Panasonic 15000 User Manual

Nortel Multiservice Switch 7400/15000/20000

Terminology

NN10600-005

Document status: Standard Document issue: 7.2S1 Document date: March 2006 Product release: PCR7.2 and up Job function: Product Fundamentals Type: NTP Language type: U.S. English

NORTEL, the globemark design, and the NORTEL corporate logo are trademarks of Nortel.

What’s new 4

Secure shell (Ssh) on Nortel Multiservice Switch 15000 and 20000 4 Load Re-balancing on Parallel Links 4

List of terms 5

Nortel Multiservice Switch 7400/15000/20000

Terminology

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Nortel Confidential

What’s new

Terms that apply to the following features were added to this document:

• Secure shell (Ssh) on Nortel Multiservice Switch 15000 and 20000

(page 4)

• Load Re-balancing on Parallel Links (page 4)

Attention: To ensure that you are using the most current version of an NTP, check the current NTP list in NN10600-000 Nortel Multiservice Switch 7400/ 15000/20000 What’s New.

Secure shell (Ssh) on Nortel Multiservice Switch 15000 and 20000

The following terms were updated for this feature:

• component model (page 32)

• Internet protocol interface over virtual circuit (IPIVC) (page 67)

• network management interface (NMIF) (page 88)

The following terms were added for this feature:

• Secure shell (Ssh) (page 118)

• Ssh (page 126)

Load Re-balancing on Parallel Links

The following term was added for this feature:

• LRB (page 78)

Nortel Multiservice Switch 7400/15000/20000

Terminology

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Nortel Confidential

List of terms

802.3

An IEEE standard defining Ethernet communications.

AAL

See ATM adaptation layer (AAL) (page 12).

AAL1

See ATM adaptation layer type 1 (AAL1) (page 13).

AAL2

See ATM adaptation layer type 2 (AAL2) (page 13).

AAList

See active alarm list (page 7).

AAL2 channel identifier (CID)

A numerical value associated with a virtual channel connection (VCC) narrowband timeslot. For non-switched trunks, the association is fixed when the VCC is established. For switched trunks, the association is made for each cell.

AAL-5

See ATM adaptation layer type 5 (AAL-5) (page 13).

A-bit signaling

See availability-bit signaling (page 16).

ABR

1 See area border router (ABR) (page 11).

ABS

2 See available bit rate (ABR) (page 16).

See ATM bearer service (ABS) (page 13).

Nortel Multiservice Switch 7400/15000/20000

Terminology

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Nortel Confidential

- 6 -

List of terms

abstract syntax notation 1 (ASN.1)

A complex data description language used for defining data in a machineindependent manner. ASN.1 is defined in ITU-T and ISO specifications.

ACC

See access call control (ACC) (page 6).

acceptable routing path

A path that satisfies the traffic requirements for an ATM PNNI call and for which the optimization metric is within the specified variance interval. Acceptable routing paths are used for ATM network load balancing.

access call control (ACC)

Nortel Multiservice Switch protocol-independent software that controls the progress and state of a call.

access delay

The time it takes to clock a frame or cell into or out of an access port on a Nortel Multiservice Switch node. In a Multiservice Switch network, the calculated value for access delay includes the serialization delay only. Access devices are assumed to be located close enough to a Multiservice Switch node so that propagation delay is ignored.

access module (AM)

A DPN-100 device that provides user access, termination, and concentration, and local data switching. Access modules can use Nortel Multiservice Switch nodes as a backbone device.

access protocol control (APC)

Software residing on a Nortel Multiservice Switch node. APC software support OSI Layers 1, 2, and 3 CCS message handling and call processing functions for connections with PBXs. See also

(page 30).

accounting gateway

A software application that runs on a workstation and is used to convert accounting records into a format usable by an IBM or VAX billing host.

common channel signaling (CCS)

accounting meter

Collects data for the frame relay egress accounting and ATM accounting features based on the end-user traffic at the entry and exit points of the networks. The meter generates accounting records from the collected data.

acknowledgment

A message that the receiving end sends to the source to indicate that it has received a transmission in good order.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 7 -

List of terms

ACR

See available cell rate (ACR) (page 16).

active alarm list

A list of active alarms, residing on each running card, that have been raised but not yet cleared.

actual shaping rate (ASR)

The shaping rate that is applied to a given ATM virtual channel connection (VCC) or virtual path connection (VPC). This value is based on the traffic descriptor type parameters and the quality of service specified for the connection, and is determined through traffic shaping.

adaptive differential pulse code modulation (ADPCM)

A widely used voice compression technique standardized by the ITU-T.

address plan

Specifies the format of the addresses that identify the network elements to which Nortel Multiservice Switch nodes can route packets. The address plan is known by every node capable of receiving such packets. The plan can be either internal or external to Multiservice Switch. Multiservice Switch uses the external DPN-100 address plan that combines ITU-T specifications X.121 and E.164 with DPN-100 RID/MID addressing.

address prefix

A string of bits that forms the lead portion of one or more ATM addresses. The length of the prefix is a maximum of 152 bits.

address resolution protocol (ARP)

A mechanism for mapping an IP network layer address to a data link layer address.

address scope

In ATM PNNI networking, a configured value for each node that participates in the network. Address scope is assigned to the node address and defines the highest level up to which the node advertises this address in the PNNI hierarchy.

address space manager (ASM)

A component in a LEN node that assigns and frees session addresses.

address summarization

In ATM PNNI networking, reduces the amount of addressing information that needs to be distributed throughout the network. Address summarization makes scaling in large networks possible. See

Nortel Multiservice Switch 7400/15000/20000

Terminology

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

summary address (page 129).

- 8 -

List of terms

adjacency

A relationship formed between selected neighboring routers for the purpose of exchanging routing information. Not every pair of neighboring routers becomes adjacent.

adjacent network identifier (ANID)

A numeric identifier assigned to an adjacent network that is directly connected to this network through at least one X.25 or X.75 gateway.

ADPCM

See adaptive differential pulse code modulation (ADPCM) (page 7).

ADTF

See allowed cell rate decrease time factor (ADTF) (page 9).

advertisement scope

See address scope (page 7).

Advisor

A Multiservice Data Manager toolset.

agent

Network management software components that are contained in managed entities such as routers, concentrators, and host computers. These components monitor the operation of the managed entity by maintaining a collection of objects in the management information base (MIB).

Agents communicate with corresponding managers.

aggregate policy

An internetworking policy through which the border gateway protocol (BGP) combines the characteristics of different routes and advertises this combination as a single route. Aggregation reduces the data that a BGP speaker stores and exchanges with another BGP speaker.

AINI

See ATM inter-network interface (AINI) (page 13).

AIR

See allowed information rate (AIR) (page 9).

AIS

See alarm indication signal (AIS) (page 9).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

alarm agent

An entity residing on every function processor (FP) and control processor (CP) that receives alarm events from a variety of services/applications.

alarm

Notification of an unusual, important, or abnormal event. An event can be degradation of service or quality of service conditions, processing errors, outof-service conditions, software errors, administrative conditions, or security violations.

alarm collector

An entity residing on the active control processor (CP) that receives alarms from its alarm agents.

alarm indication signal (AIS)

1 A signal transmitted in lieu of the normal signal to maintain transmission

continuity and to indicate to the receiving equipment that there is a transmission interruption located either at the equipment originating the AIS signal or upstream of that equipment.

- 9 -

List of terms

2 A signal transmitted in the downstream direction from a point of failure.

The AIS signal is used at the physical and ATM layers.

A-law

A technique for translating pulse code modulated voice into 64 kbit/s digital voice channels. A-law is used in countries that use E1 function processors. See also

mu-law (page 83).

allowed cell rate

In ATM ABR networking, the rate at which the ABR source is allowed to transmit cells into the network. The allowed cell rate for an ABR connection varies dynamically as resource availability changes along the connection.

allowed cell rate decrease time factor (ADTF)

In ATM ABR networking, the time interval permitted between sending forward resource management (FRM) cells before the allowed cell rate is decreased to the initial cell rate (ICR). If the source does not transmit an FRM cell for a period of ADTF centiseconds (hundredths of a second), it reduces its allowed cell rate to the value of its ICR. If the allowed cell rate is already at or below ICR, further rate reductions are defined by the ABR FRM cell limit.

allowed information rate (AIR)

A pro-active congestion control mechanism used by the network that reduces allocated bandwidth when congestion occurs and by doing so discards frames in a controlled fashion.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

List of terms

alternate clock master

For Nortel Multiservice Switch 7400 nodes, the bus tap in slot 0 or slot 15, which is the alternate clock signal for a backplane bus. This term can also be applied to the processor card that contains the bus tap. See also

(page 28).

alternate mark inversion (AMI)

A digital line encoding technique in which a zero is transmitted by no pulse while a one is transmitted by a pulse opposite in polarity to the previous pulse.

alternate path

An optional pre-determined path for a specified path connection. The alternate path acts as a backup in case the primary path fails.

See access module (AM) (page 6).

- 10 -

clock master

AM cluster

A set of DPN-100 access modules (AM) and routing identifiers (RID), where these AMs and RIDs have been grouped for routing purposes. Each AM cluster can have up to two RIDs. Each RID can be a member of more than one AM cluster.

American standard code for information interchange (ASCII)

A standards-based format for text files, in which each character is represented as a 7-digit binary string. There are 128 characters. There are variations, notably for Windows NT and derivative operating systems and IBM System 390 servers. There is also extended ASCII, which includes up to 256 characters.

AMI

See alternate mark inversion (AMI) (page 10).

American National Standards Institute (ANSI)

An organization that establishes voluntary industry standards.

ancestor node

An ancestor node is a node that has a parent relationship to a given node.

ANID

See adjacent network identifier (ANID) (page 8).

ANSI

See American National Standards Institute (ANSI) (page 10).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

APC

See access protocol control (APC) (page 6).

APS

See automatic protection switching (APS) (page 15).

application

Nortel Multiservice Switch software is partitioned into distinct software applications. Applications contain features that are loaded on cards to provide services. A

Multiservice Switch node can run multiple software applications simultaneously. An example of an application is frame relay service. See also

application version (AV) (page 11).

application journaling

Represents the journaling of operational data between active and standby applications

- 11 -

List of terms

application-specific integrated circuit (ASIC)

An integrated circuit that performs a set of specific processes more quickly and efficiently than a generic processor.

application version (AV)

A particular version (or release) of an application.

application version list (AVL)

Specifies the version level of all applications that are configured to run on a Nortel Multiservice Switch node.

AQM

See ATM queue manager (AQM) (page 14).

Architect for Passport

A Multiservice Data Manager toolset.

area border router (ABR)

Connects one or more OSPF areas and the backbone in IP networking. ABRs condense or summarize the topological data of their attached areas for distribution on the backbone. The backbone in turn distributes the information to other areas.

ARP

See address resolution protocol (ARP) (page 7).

See autonomous system (AS) (page 15).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

ASBR

ASCII

ASIC

ASM

ASN.1

ASPEN

- 12 -

List of terms

See autonomous system boundary router (ASBR) (page 15).

See American standard code for information interchange (ASCII) (page 10).

See application-specific integrated circuit (ASIC) (page 11).

See address space manager (ASM) (page 7).

See abstract syntax notation 1 (ASN.1) (page 6).

See voice gateway control protocol (VGCP) (page 145).

ASR

See actual shaping rate (ASR) (page 7).

AS weight policy

See autonomous system weight policy (page 15).

associated signaling

Uses one dedicated path between nodes as the signaling link.

asynchronous transfer mode (ATM)

A technology that provides access to a network by multiplexing user information into fixed-length units called cells. ATM forms the basis for broadband networks.

ATM

See asynchronous transfer mode (ATM) (page 12).

ATM accounting

Collects usage information in the form of cell counts for ATM connections. The service provider can use this information to bill customers or for test purposes, statistics, network engineering, and planning.

ATM adaptation layer (AAL)

The standards layer that allows multiple applications to convert data to and from a set of ATM cells. AAL translates higher layer services into the size and format of an ATM cell.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 13 -

List of terms

ATM adaptation layer type 1 (AAL1)

An AAL protocol used to transfer constant bit rate traffic such as voice and video.

ATM adaptation layer type 2 (AAL2)

An AAL protocol used to transfer variable bit rate traffic.

ATM adaptation layer type 5 (AAL-5)

An AAL protocol used to transfer variable bit rate, delay-tolerant, connectionoriented traffic that requires minimal sequencing or error detection support.

ATM anycast capability

An ATM routing and signaling feature that allows a user to request a point-topoint connection to a single ATM end system that is part of an ATM group.

ATM bearer service (ABS)

Nortel Multiservice Switch ATM node’s bearer service allows ATM users and external equipment (ATM hubs, routers, workstations, servers, and videoconferencing equipment) access to the service provides sequence-preserving connection-oriented cell transfer between source and destination with a defined quality of service and throughput.

Multiservice Switch network. This

ATM bus controller (ABC)

A bus controller on a Nortel Multiservice Switch ATM node’s function processor.

ATM interface CAC (AtmIf-CAC)

A connection admission control (CAC) technique that applies to independent virtual channel connections (VCC) and virtual path connections (VPC) under an ATM interface. Compare with

(page 143).

AtmIf-CAC

See ATM interface CAC (AtmIf-CAC) (page 13).

ATM inter-network interface (AINI)

ATM Forum standard signaling protocol that provides interconnection between Nortel Multiservice Switch nodes as well as interconnection between Multiservice Switch and non-Multiservice Switch nodes (Nortel Networksfamily devices and devices from other vendors).

virtual path termination CAC (VPT-CAC)

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

ATM IP function processor

Nortel Multiservice Switch ATM node function processor that uses the Multiservice Switch queue controller (PQC) and ATM queue manager (AQM) ASICs to provide enhanced cell processing and ATM traffic management capabilities.

ATM layer

A layer in the B-ISDN protocol stack that transfers ATM cells. It is positioned between the physical layer and the AAL.

ATM link

A standards-based ATM connection.

ATM logical multicasting

Logical multicasting creates additional VCCs on the same output port of a node, thus allowing more than one replicated copy of the same cell to be delivered to the same output port. This in turn enables cell replication for transport over ATM networks that do not support multicasting.

- 14 -

List of terms

ATM multiprotocol encapsulation service

A service that supports two encapsulation methods for carrying connectionless network interconnect traffic over AAL-5. The first method is logical link control (LLC) encapsulation, which permits multiple protocols over a single ATM virtual circuit (VC). The second method is VC encapsulation, which permits one protocol over each ATM VC.

ATM network multicasting

Network multicasting is performed at each node in the ATM network to determine where branch points for a PMP call are required. Once a branch point is identified, spatial multicasting techniques are utilized to replicate the cell stream.

ATM networking

Encompasses the standards-based UNI, IISP, AINI, and PNNI routing and signaling protocols.

ATM queue manager (AQM)

A hardware chip on ATM IP function processors. The AQM performs traffic management functions such as per-VC queuing, shaped fair queuing, and processing for available bit rate (ABR) traffic.

ATM spatial multicasting

Spatial multicasting delivers replicated cells to different output ports on the same node, thus permitting the routing of cells from the same node to different destinations.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 15 -

List of terms

attribute

Defines the behavior or information associated with a specific component. Attributes are either operational or provisionable. See also

attribute (page 93) and provisionable attribute (page 107).

attribute type

Specifies the structure of the attribute’s value (for example, decimal, hex, BCD, integer, or IP address).

attribute value

The current setting for an attribute. The structure of the value is dictated by the type of attribute.

automatic protection switching (APS)

APS detects faults in SONET or SDH lines that are connected to the active function processor. Under line APS, two SONET or SDH lines are defined: working and protection. Either line can be active. Line APS monitors the line that is active and when necessary causes the card to switch to the other line.

operational

autonomous system (AS)

An autonomous system is one or more networks that are under the control of one enterprise. These networks are usually under the control of a single routing protocol.

autonomous system boundary router (ASBR)

An ASBR is a gateway between autonomous systems. ASBRs are the backbone of the Internet.

autonomous system weight policy

The autonomous system weight policy allows you to set a preference for some autonomous systems and discriminate against others. You can assign each autonomous system a weight, where the border gateway protocol (BGP) prefers the path with lowest weight.

See application version (AV) (page 11).

AVL

See application version list (AVL) (page 11).

availability

The percentage of time during which a device or service is ready for use.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 16 -

List of terms

availability-bit signaling

The availability-bit (A-bit) signaling technique exchanges availability status between the two ends of a frame relay permanent virtual channel (PVC) connection. A-bit signaling permits each end of a PVC to determine if the remote end is ready to process data.

availability message packet (AMP)

An availability message packet (AMP) is a status message sent by a hunt group member to its hunt group server. A hunt group member sends an AMP each time its availability status changes significantly.

available bit rate (ABR)

An ATM service category. ABR permits dynamic allocation of bandwidth to applications that are highly tolerant of cell delay and delay variance, such as LAN interconnection. ABR traffic is characterized as very bursty.

available cell rate (ACR)

The available capacity of an ATM link. In general, ACR refers to links that are already in use by one or more ATM connections.

B-channel

See bearer channel (B-channel) (page 19).

B-ICI

See broadband inter-s interface (B-ICI) (page 21).

B3ZS

See binary 3 zero substitution (B3ZS) (page 19).

B8ZS

See binary 8 zero substitution (B8ZS) (page 19).

backbone

A group of interconnected core nodes that normally tandem traffic. A backbone node exchanges full topology information with all nodes in the same topology region that are not cluster nodes. The backbone exchanges limited routing and no topology information with clusters. The backbone does not exchange any information with nodes in other topology regions.

backbone border node

Nortel Multiservice Switch nodes that reside on a backbone boundary, connected by backbone-cluster border links to cluster nodes.

backbone node

Nortel Multiservice Switch nodes that reside within a backbone.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

backbone router

A router that has an interface to the backbone, including area border routers (ABR). A backbone router that has connections only to other backbone routers also functions as an internal router.

backplane

The printed circuit board into which control and function processors on a shelf are seated. The backplane serves two functions: distributes power to all processor cards on the shelf, and supports the bus that transports data and signaling between processor cards.

backplane bus

A cell-based 800 Mbit/s bus. The backplane bus allows each processor card in a shelf to send data or signaling to any other processor card. There are two backplane buses for each shelf: X and Y.

- 17 -

List of terms

backplane control system (BCS)

The software system that manages the operation of the Nortel Multiservice Switch

15000 and Multiservice Switch 20000 fabrics. The BCS controls the fabrics on each processor card, allowing applications to send and receive frames over the backplane X and Y fabrics. The BCS also monitors the state of the fabrics to ensure that all cards can communicate. Lastly, the BCS allows the operator to monitor and test the fabrics.

backplane fabric

A cell-based 56.3 Gbit/s fabric. The backplane fabric allows each processor card in a shelf to send data or signaling to any other processor card. There are two backplane fabrics for each shelf: X and Y.

backplane file system (BFS)

The file system that enables a processor card to access files on either the active or standby control processor across the backplane.

backward congestion indication (BCI)

A bit in the Nortel Multiservice Switch packet header that indicates that packets travelling in the opposite direction on the connection are encountering congestion.

backward explicit congestion notification (BECN)

The bit in a frame relay header that indicates congestion in the path for the direction opposite to the direction in which the frame is flowing.

backward resource management cell (BRM)

Forward resource management cells that the ABR destination device turns around for delivery to the available bit rate source. See

management cell (FRM) (page 54).

Nortel Multiservice Switch 7400/15000/20000

Terminology

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

forward resource

- 18 -

List of terms

bandwidth-elastic connection

See elastic connection (page 47).

bandwidth-non-elastic connection

See non-elastic connection (page 90).

bandwidth management

Allows both connectionless and path-oriented traffic to share the same Nortel Multiservice Switch trunk while ensuring that trunk bandwidth is not oversubscribed to by circuits carrying voice and video traffic. Bandwidth is reserved for the duration of a logical connection and can be partitioned among services according to their priorities, minimizing the probability that voice and video traffic is discarded.

bandwidth on demand (BWOD)

Capability enabling users to acquire varying amounts of bandwidth on request.

bandwidth pools

In ATM traffic management, a method of reserving by service category a percentage of link bandwidth (known as a bandwidth pool) for connections.

basic rate interface (BRI)

The interface between an ISDN subscriber and the ISDN switch (that is, the local loop). The interface consists of two 64 kbit/s B-channels and one 16 kbit/ s D-channel.

basic virtual path terminator

A type of virtual path terminator that provides traffic management at the VC level only.

See committed burst size (Bc) (page 30).

See bus controller (BC) (page 22).

BCD

See binary-coded decimal (BCD) (page 19).

BCI

See backward congestion indication (BCI) (page 17).

BCS

1 See bus control system (BCS) (page 22).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

2 See backplane control system (BCS) (page 17).

See excess burst size (Be) (page 50).

bearer channel (B-channel)

In ISDN connections, a 64 kbit/s digital bidirectional channel for carrying voice and data traffic.

BECN

See backward explicit congestion notification (BECN) (page 17).

beginning of message (BOM)

The first cell in a series of cells that result from segmentation of higher-layer packets or frames. The BOM cell marks the first cell in the cell series that represents one packet or frame.

- 19 -

List of terms

BFS

See backplane file system (BFS) (page 17).

BGP

See border gateway protocol (BGP) (page 20).

binary 3 zero substitution (B3ZS)

An encoding technique used to transfer bits over a DS3 line. B3ZS guarantees 1’s density by substituting a pattern of bipolar violations if three or more zeros in a row are to be transported.

binary 8 zero substitution (B8ZS)

An encoding technique used to transfer bits over a DS1 line. B8ZS guarantees 1’s density by substituting a pattern of bipolar violations if eight or more zeros in a row are to be transported.

binary-coded decimal (BCD)

1 A computer coding system that represents each decimal number with a

group of four binary digits (1s and 0s).

2 A component model data type.

bipolar violation (BPV)

A failure to follow alternate mark inversion coding. BPVs are intentionally inserted in the bit stream using 1’s density techniques.

bit 7 stuffing

When a T1 or E1 time slot has all 0s, bit 7 (the least significant bit) is forced to a 1.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 20 -

List of terms

BITS

See building-integrated timing supply (BITS) (page 21).

bit-transparent data service (BTDS)

Nortel Multiservice Switch application that transports continuous synchronous data (isochronous) that has already been subjected to some form of encoding across the network without interpretation. The continuous data stream is broken into fixed sized cells and sent through the network.

block

A a series of contiguous memory locations. User data is stored in a block. All blocks are assumed to be the same length, usually a binary (power of 2) number of words. Memory blocks are linked together to form buffers.

BNX

The Bay Networks network element running hyperstream software.

BNX-Iwf

BNX interworking function. The set of capabilities that permits frame relay services over IP connections between virtual routers on a Nortel Multiservice Switch

15000 or Multiservice Switch 20000 node and a Bay Networks network element running hyperstream software (BNX).

BNX-Iwf DLCI

BNX interworking function DLCI. A type of FrUni DLCI that is required for interworking between the Bay Networks network element running hyperstream software (BNX) and the Nortel Multiservice Switch Multiservice Switch

20000 node supporting frame relay over IP.

BOM

See beginning of message (BOM) (page 19).

border gateway protocol (BGP)

Border gateway protocol (BGP) is an inter-autonomous systems routing protocol for the Internet.

border node

A logical node at the edge of some kind of networking boundary, such as a topology region, peer group, or cluster.

15000 or

bootstrap router (BSR)

A dynamically elected router within a PIM domain that is responsible for constructing the RP-Set and originating bootstrap messages.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 21 -

List of terms

BPV

See bipolar violation (BPV) (page 19).

break-before-make rerouting

See connection recovery (page 33).

BRI

See basic rate interface (BRI) (page 18).

BRM

See backward resource management cell (BRM) (page 17).

broadband inter-s interface (B-ICI)

An interface between public ATM networks.

broadcast

To send one or more messages to multiple addresses on one or more networks.

BSR

See bootstrap router (BSR) (page 20).

See burst tolerance (BT) (page 22).

BTDS

See bit-transparent data service (BTDS) (page 20).

buffer

A linked list of blocks. The blocks that make up a buffer are not necessarily contiguous. Buffers are composed of multiple blocks when the user data does not fit into a single block. The linkage of blocks to form a buffer is managed by the queue controller.

buffer memory

See shared memory (page 121).

building-integrated timing supply (BITS)

The most accurate and stable clock source within a physical structure. All digital equipment in the structure receives timing reference from the same master clock. BITS derives its signal from a stratum-3E or better reference signal. BITS provides network clock synchronization through external timing to the Nortel Multiservice Switch Multiservice Switch

20000 node.

7400, Multiservice Switch 15000, or

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

bundle

Grouping of one or more physical links using the formats and procedures of the multilink frame relay (MLFR) standards. The bundle operates as a logical interface function that emulates a single physical interface to the Q.922 data link layer.

bundle link

A multilink frame relay (MLFR) sub-component that controls operation of one of the bundle’s physical links.

burst tolerance (BT)

A characteristic of ATM usage parameter control applied to traffic defined through traffic descriptor types 6, 7, and 8, and is based primarily on the MBS value defined in parameter 3 for each of these types. BT is defined as MBS minus 1 multiplied by the difference between the PCR and SCR cell intervals. BT, together with SCR and the GCRA, determines the MBS that can be transmitted at the PCR.

- 22 -

List of terms

bus

The Nortel Multiservice Switch node bus.

bus control system (BCS)

The software system that manages the operation of the Nortel Multiservice Switch node bus.

bus controller (BC)

A Nortel Multiservice Switch ASIC that allows a processor card to send and receive data and to control information over a backplane bus. There are two bus controllers for each processor card, one for each 800 Mbit/s bus.

bus mode

A property of a Nortel Multiservice Switch node that indicates the number of backplane buses that are currently in service (for example, single-bus mode or dual-bus mode).

bus tap

The interface between a processor card and the backplane bus. The bus tap consists of a bus controller ASIC and some additional backplane interface logic. There are two bus taps for each processor card.

bus terminator card

A printed circuit board that terminates backplane traces, thereby reducing errors on the backplane buses by eliminating signal reflection. Each shelf contains two bus terminator cards, one at each end of the backplane.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 23 -

List of terms

BWOD

See bandwidth on demand (BWOD) (page 18).

cable management area

One of the four divisions of the shelf. It allows orderly management of cables and acts as an exhaust duct for hot air.

cache management system (CMS)

A feature that allows the user to configure the IP local cache table size.

CAC

See connection admission control (CAC) (page 33).

call

Communication between two subscribers who are connected to endpoints of the network.

call correlation tag (CCT)

An identifier, unique for each call, provided in the accounting record to facilitate off-switch correlation of several records issued at different interfaces in the network.

call establishment

Establishing a call between two access services across a network.

call management

The capability of the Nortel Multiservice Switch accounting system to prevent the loss of accounting records by only accepting new SVC calls if the system has enough resources to process the accounting records associated with the SVC call. Call management is engineered for each logical processor.

call preservation

See connection preservation (page 34).

call redirection server (CRS)

Provides call redirection for DPRS services on Nortel Multiservice Switch node-only networks. A CRS improves an application’s availability by redirecting a call attempt that would otherwise fail because the destination cannot be reached. Call redirection servers are located on function processors that are spread throughout the routing identifier (RID) subnet in the DPRS network.

call router (CR)

Provides the translation of a DNA to a routable identity.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 24 -

List of terms

call server resource module (CSRM)

A DPN-100 resource module that is directly connected to and provides call server functions for a Nortel Multiservice Switch network.

candidate bootstrap router (C-BSR)

A router configured to participate in a BSR election and acts as a BSR if elected.

candidate rendezvous point (C-RP)

A router configured as a potential rendezvous point for a specified range of multicast addresses.

CAR

See connection address resolution (CAR) (page 32).

card

An electronic circuit board. In Nortel Multiservice Switch documentation, card usually refers to a processor card (either a function processor or a control processor).

card port

An interface between the fabric card and the processor cards of the Nortel Multiservice Switch

15000 or Multiservice Switch 20000 node.

Carrier’s Carrier

The feature, service or configuration that offers BGP/MPLS VPN services to other service providers also offering BGP/MPLS VPN services to their end customers. Also referred to as hierarchical BGP/MPLS VPNs.

Carrier’s Carrier customer edge router (CE’)

The Passport router that interfaces with the Carrier's Carrier PE router (PE') and performs label distribution functionality between the customer carrier and the Carrier's Carrier in order to utilize the MPLS VPN transit service provided by the Carrier's Carrier. The CE' node also acts simultaneously as a PE router to the end CE router of the customer carrier.

Carrier’s Carrier provider edge router (PE’)

The router that offers the Carrier's Carrier service to the CE' router.

CAS

1 See component administration system (CAS) (page 31).

2 See channel-associated signaling (CAS) (page 27).

CAW

See cumulative administrative weight (CAW) (page 37).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

CBC

CBR

C-BSR

CCITT

- 25 -

List of terms

See connection bandwidth control (CBC) (page 33).

See constant bit rate (CBR) (page 34).

See candidate bootstrap router (C-BSR) (page 24).

See congestion control (CC) (page 32).

See Comité Consultatif International Télégraphique et Téléphonique (CCITT)

(page 30).

CCR

CCS

CCT

CDL

CDMA

CDV

CDVT

C-RP

See current cell rate (CCR) (page 37).

See common channel signaling (CCS) (page 30).

See call correlation tag (CCT) (page 23).

See component description language (CDL) (page 31).

See code-division multiple access (page 29)

See cell delay variation (CDV) (page 26).

See cell delay variation tolerance (CDVT) (page 26).

See candidate rendezvous point (C-RP) (page 24).

See “customer edge device or router (CE)” (page 37).

CE’

See “Carrier’s Carrier customer edge router (CE’)” (page 24).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 26 -

List of terms

cell

A small, fixed-length data unit, with associated control header (cell header), that is transmitted across the network. Many cells can be required to carry a complete message for a customer. The ATM cell is 53 bytes long.

cell delay variation (CDV)

The allowable variation in time that a cell can take to travel over a virtual connection. Also, the measurable variation in the interval between ATM cells arriving at a network element. The accumulation of this variation results in cell clumping. Also known as cell delay variance.

cell delay variation tolerance (CDVT)

One of a set of ATM traffic characterization values. CDVT defines the tolerance to cell clumping that results from the accumulating amount of cell delay variation or “jitter” in the network or customer premises equipment (CPE). CDVT is Nortel Multiservice Switch node-specific and is not part of the ATM Forum specification.

cell header

Information wrapped within a cell that determines the destination of the cell and carries sequencing and error detection information.

cell loss priority (CLP)

A bit located in the ATM cell header that identifies the priority of the cell as eligible for discard at a point of congestion.

cell loss ratio (CLR)

The allowable percentage of cells that can be lost for a given traffic type. CLR is the ratio between ATM cells transmitted by the source over a link and the number of cells discarded by the destination due to congestion. CLR is a QOS class parameter that defines the loss ratio that the service provider agrees to over the lifetime of a connection.

cell queue controller (CQC)

The hardware chip that supports traffic shaping and usage parameter control on ATM interfaces and connections, and that permits per-VC queuing. The CQC ASIC defines the series of CQC ATM function processors as distinct from other series of ATM function processors.

cell queue memory (CQM)

The RAM memory used by the cell queue controller (CQC). This memory is used as buffer space for the link transmit queues, reserved space, and connection space.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

List of terms

cell switching

A hardware-based switching technology in which data entering the network is broken down into one or more fixed-length cells. The cells are transported independently through the network and reassembled at the destination.

cell transfer delay (CTD)

The time it takes a cell to travel from one end of a virtual connection to the other. CTD is also defined as the measurable elapsed time between an exit event at a measuring point (the source UNI) and an entry event at a measuring point (the destination UNI). This measurement is the sum of the total internode transmission delay and the total node processing delay between the two measuring points.

central processing unit (CPU)

The main processing unit of a device that performs program sequencing and arithmetic logic.

- 27 -

CES

See circuit emulation service (CES) (page 28).

channel

The smallest subdivision of a circuit that provides a single type of communication service.

channel-associated signaling (CAS)

Signaling used in voice or modem connections in which specific bits in the DS1 or E1 frame structure carry the ABCD signaling information for each channel.

channel service unit (CSU)

A type of interface used to connect a terminal or computer to a digital medium. A CSU also performs diagnostic and protective functions, such as providing a keep-alive signal to maintain line synchronization.

child node

In an ATM PNNI network, a node at the next lower level of the hierarchy where that node is contained in the peer group represented by the logical group node currently referenced. The child node can be a logical group node or a physical node.

child peer group

A child peer group of a peer group is any one group that contains a child node of a logical group node in that peer group.

CID

See customer identifier (CID) (page 38).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 28 -

List of terms

CIDR

See classless inter-domain routing (CIDR) (page 28).

CIR

See committed information rate (CIR) (page 30).

circuit emulation service (CES)

A service that converts and transports data from one circuit format to another. For example, a CES can convert DS1 circuit data to ATM cells at the ingress node for transport over an ATM network, and then reconvert the data to its original DS1 circuit format at the egress node.

Class A, B, and C (internetworking)

Address ranges for Internet addressing. These ranges are based on the first eight bits of the address. Each range allows less of the whole address for host addresses than the previous range.

• A Range from 1 to 126. This class is used for networks that have up to 224

nodes, such as government agencies and major university systems. Default address mask of 255.0.0.0.

• B Range from 128 to 191. This class is used for networks that have up to

nodes, such as large corporations. Default address mask of

255.255.0.0.

• C Range from 192 to 254. This class is used for smaller networks that

have fewer than 255 nodes, such as smaller colleges and businesses. Default address mask of 255.255.255.0.

class of service (IP CoS)

A Nortel Multiservice Switch IP differentiated service feature that provides limited IP traffic management.

classless inter-domain routing (CIDR)

An internetworking protocol that uses subnetwork masks other than the defaults used for IP address classes. Defined in RFC1517 and RFC1518.

clock master

The bus tap in slot 0 or 15 that supplies clock signals for a backplane bus. This term can also be used for the processor card that contains this bus tap.

closed user group (CUG)

A collection of users whose members are governed by certain rules of access with respect to communication with each other, with members of other closed user groups, and with the open part of the network. These rules maintain security, prohibit unauthorized access. and provide logical partitioning of the network for better access control.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

CLP

See cell loss priority (CLP) (page 26).

CLR

See cell loss ratio (CLR) (page 26).

CLR alarm

An alarm that is issued subsequent to an associated SET alarm when the fault condition no longer applies. These alarms have an activeListStatus value of “CLR”.

cluster

See Multiservice Switch cluster (page 85).

cluster border node

Nortel Multiservice Switch nodes that reside on a cluster boundary, connected by backbone-cluster border links to the backbone.

- 29 -

List of terms

cluster node

Nortel Multiservice Switch nodes that reside within a cluster.

CMS

See cache management system (CMS) (page 23).

CNLS

See connectionless routing (CNLS) (page 33).

CNM

See customer network management (CNM) (page 38).

See connection-oriented routing (CO) (page 34).

COI

See community of interest (COI) (page 31).

code-division multiple access

A method of allowing multiple users to access the same system by assigning them different digital codes which they can use to decode their desired narrowband information from the stream's wideband composite signal.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 30 -

List of terms

cold standby

Applications and features that operate with a standby instance that is not synchronized with the active instance of the software. During an equipment switchover, cold standby applications incur longer outages than hot standby and warm standby applications, and all connections must be re-established.

COM

Continuation of message. See beginning of message (BOM) (page 19).

Comité Consultatif International Télégraphique et Téléphonique (CCITT)

A European standards body now known as ITU-T.

command area

An adjustable segment of a window where you enter and review commands. The command area contains two fields: a command (input) field and a history field.

command file

A set of instructions stored as a macro. When the command file is executed, all instructions or commands in that file are performed automatically.

command line interface

An area on a terminal screen that allows you to enter instructions from the keyboard and then execute those instructions.

committed burst size (Bc)

The maximum amount of data (in bits) that a network agrees to transfer under normal conditions over a measurement interval.

committed information rate (CIR)

The rate (in bit/s) at which the network agrees to transfer information over a connection. It is related to committed burst size (Bc) and measurement interval (T) as CIR = Bc/T.

common header

A small Nortel Multiservice Switch node-specific common frame header that is appended to the front of frames and cells that are routed between Nortel Multiservice Switch nodes.

common channel signaling (CCS)

A signaling system in which signaling control data for all channels on a facility is carried on a single separate channel in the form of a data protocol. For example, the control signals for 30 voice channels are carried on an ISDN PBX trunk, and the data channel (D-channel) is carried in one of the remaining channels.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 31 -

List of terms

common part convergence sublayer (CPCS)

A sublayer of the AAL-5 layer.

common queuing

An ATM queuing structure in which traffic from two or more connections is placed on a single queue during node congestion. Traffic is processed in round-robin fashion within the common queue. Compare with

(page 101).

common transmit clock (CTC) mode

An IMA configuration in which the same transmit clock is used for all physical links in the IMA group. This configuration contrasts with independent transmit clock (ITC) mode.

community of interest (COI)

The source and destination of communications traffic. Two common COIs referred to are as follows:

PHB

1 A local COI refers to the traffic entering on access ports of a Nortel

Multiservice Switch node that is destined for another port on the same node.

2 A network COI refers to a matrix of inter-node traffic in the network. For

each node in a network, the matrix has an entry for the volume of data originating from that node and terminating on the other nodes in the network.

component

Used by the network operator or administrator to control Nortel Multiservice Switch software, hardware, capabilities, and access services. Each component represents some part of the Multiservice Switch network—a service, a piece of software, or a physical hardware element. Standardized and organized in a highly structured fashion, components provide the model for operator interaction with Multiservice Switch. All commands for provisioning, monitoring, and maintenance are addressed to components.

component administration system (CAS)

The command and control system that processes network management requests by passing them to the appropriate components for action and returns the results to the source of the request. CAS also provisions and creates components on the Nortel Multiservice Switch node. In addition, when working with the network management interface system (NMIS), CAS provides the provisioning view for external network management systems.

component description language (CDL)

A proprietary data modeling language for Passport managed objects. CDL is encoded within FrameMaker .cdf files or ASCII .cdl files.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

component instance

When more than one of a component type exists, they are differentiated by an instance value. The instance value is information (such as a decimal or a string) appended to the component type.

component model

An OSI-like management model describing Nortel Multiservice Switch nodes in terms of a set of components arranged into hierarchies. Components contain attributes that are arranged in attribute groups. Components support verbs that take options. A verb applied to a component can produce responses. Components can also produce asynchronous responses, such as alarms. The component model is supported over the local, Telnet, Ssh, and FMIP NMIFs. It is indirectly supported within the Multiservice Switch enterprise SNMP MIB.

component type

The part of the component name that identifies the component being referred to. For example, FrameRelayUni is the component type of the component name FrameRelayUni/4.

- 32 -

List of terms

congestion state

An indication of the degree of congestion of a memory entity such as a queue or free list. On ATM FPs, there are four congestion states, where 0 is the most congested and 3 is the least congested. When a memory entity is in congestion state x, all data of discard priority greater than x is discarded.

congestion control (CC)

ATM mechanisms that detect, prevent, and correct traffic congestion.

conjugate-structure, algebraic-code-excited linear prediction (CSACELP)

An 8 kbit/s compression algorithm used to encode voice data, based on ITU-T recommendation G.729.

connection

A channel or path between two network entities. The channel or path can be either physical or virtual. A network entity is any system or subsystem that is attached to the network medium.

connection address resolution (CAR)

The protocol by which a data network address is resolved into a routable destination on the network for the purpose of establishing a call connection.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 33 -

List of terms

connection admission control (CAC)

A preventative ATM traffic management strategy through which Nortel Multiservice Switch nodes evaluate a connection request based on the traffic characteristics of both established connections and the requested connection. The request is accepted if the new connection does not jeopardize the QOS of established connections.

connection bandwidth control (CBC)

Connection bandwidth control guides the response of ATM connections to changes in bandwidth available over an ATM link.

connection recovery

A process of finding an alternate route for a failed connection that would have been cleared back to the end-user. In connection recovery, the incumbent connection segment is released before the establishment of an alternate connection segment. Connection recovery is also known as hard rerouting and break-before-make rerouting.

connection segment

A portion of an end-to-end connection or the entire end-to-end connection, spanning a series of intermediate nodes across a PNNI network.

connection scope

The PNNI routing level above which the network cannot route calls.

connection scope selection information element (CSS-IE)

A signaled information element that is used in ATM anycast call requests. CSS-IE in the call setup message permits the calling endstation to constrain a point-to-point connection request using the ATM anycast capability to group members within a specified level of routing hierarchy.

connection trace

A control plane mechanism that determines the physical nodes and physical links traversed by existing connections that have already been established.

connectionless routing (CNLS)

A point-to-point routing service where a message’s path through the network is not specified during the call establishment phase. Instead, the path for each data unit (a frame or cell) of a message is calculated independently and dynamically. Each path is based on the destination address of the frame, current network topology, and available bandwidth. Connectionless routing features a high degree of robustness and reliability, since data can be easily steered away from failed or heavily congested facilities.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 34 -

List of terms

connection-oriented routing (CO)

A routing service in which the path used by the frames or cells is determined when the connection is set up and remains fixed for the duration of the connection (barring network problems). Each path is set up on the nodes of that path and each packet needs a minimum of routing information.

connection preservation

The process of maintaining a connection over a sequence of potentially disruptive events such that the connection does not need to be reestablished when that sequence of events is complete.

Also known as call preservation.

constant bit rate (CBR)

An ATM Forum UNI 4.0 quality of service (QOS) class. This QOS class defines a static bandwidth that is continuously available for the duration of a connection. Corresponds to UNI 3.0/3.1 QOS class 1 and to Nortel Multiservice Switch constant bit rate QOS class.

Networks use CBR for voice, video, and telemetry services that need carefully metered transmission rates. In this sense, CBR emulates individual private line service. CBR avoids disagreeable “glitches” in service quality that result from data rate variance and data losses.

continuation of message cells (COM)

All cells in a stream between the beginning of message cell and the end of message cell, all of which belong to a series of cells that result from segmentation of higher-layer packets or frames.

control plane (C-plane)

Defines all aspects of the management and control of frame relay. The local management interface (LMI) is the interface to the C-plane. It uses procedures defined in

• Frame Relay User-to-Network Interface With Extensions, document

number 001-208966 (available through Nortel Networks)

• ANSI T1.617 Annex D

• ITU-T Q.933 Annex A

For more information, see NN10600-900 Nortel Multiservice Switch 7400/ 15000/20000 Frame Relay Technology Fundamentals.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

List of terms

control plane protection (CPP)

An IP feature designed to protect the Nortel Multiservice Switch against certain denial of service (DoS) attacks on the control plane. This control plane can be defined as all packets that have locally destined IP addresses within a VR, VCG, RTR, or VRF address space and are terminating on the Multiservice Switch node.

control processor (CP)

A type of processor card optimized to support the software that performs complex, memory-intensive processes. Among other things, these processes parse operator commands, and modify and display provisioning data. The control processor also supports the administration interfaces for the Nortel Multiservice Switch node. Each node must have an active control processor and can also have (for redundancy) a standby control processor. Each control processor contains the disk, a DCE V.24 interface, and an Ethernet interface to manage the node.

- 35 -

control processor (CP) switchover

The process of the standby CP becoming active. This process can occur upon CP failure, restart of the active CP, a manual reset of the CP, or when a switchover is invoked manually using the “Switchover Lp” command.

convergence sublayer (CS)

A sublayer of an ATM adaptation layer.

Coordinated Universal Time (UTC)

A time standard that Nortel Multiservice Switch software uses for establishing network time, that is equivalent to Greenwich Mean Time (GMT). GMT is the time at the Greenwich meridian (0 degrees longitude).

cooling unit

The cooling unit is a hardware component of a Nortel Multiservice Switch node. It contains a forced-air cooling system that ensures adequate cooling of the processor cards. For more information, see NN10600-170 Nortel

Multiservice Switch 7400 Hardware Description or NN10600-120 Nortel Multiservice Switch 15000/20000 Hardware Description.

core networking

Encompasses the three Nortel Multiservice Switch networking systems: PORS, and DPRS.

CoS

See class of service (IP CoS) (page 28).

See control processor (CP) switchover (page 35)

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

CPP

CPCS

CPE

CPeD

C-plane

CQC

- 36 -

List of terms

See control plane protection (CPP) (page 35)

See common part convergence sublayer (CPCS) (page 31)

Customer premises equipment.

A control processor with external (BITS) DS1 timing support.

See control plane (C-plane) (page 34).

See cell queue controller (CQC) (page 26).

CQC function processor

A type of Nortel Multiservice Switch ATM node function processor that uses a cell queue controller (CQC) ASIC. This type of function processor was the original ATM FP on Multiservice Switch nodes.

CQM

See cell queue memory (CQM) (page 26).

crankback

A mechanism in ATM networking that partially releases a connection setup in progress when that setup request encounters a failure in the network. This mechanism allows ATM routing protocols to perform alternate routing.

See call router (CR) (page 23).

critical IP address

An IP interface on the local router. If the VRRP virtual router configuration includes a critical IP interface address, a change in state to that IP interface causes a role switch in that VRRP virtual router.

CRC-4

A cyclic redundancy check pattern used on an E1 line.

CRC-6

A cyclic redundancy check pattern used in extended superframe (ESF) mode on a DS1 line.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

cross-net polling

The process of periodically exchanging a status message across the subnet between the two end points of a PVC. This message indicates the status of the source to the destination.

CRS

See call redirection server (CRS) (page 23).

CS-ACELP

See conjugate-structure, algebraic-code-excited linear prediction (CS-

ACELP) (page 32).

CSRM

See call server resource module (CSRM) (page 24).

CSS-IE

See connection scope selection information element (CSS-IE) (page 33).

- 37 -

List of terms

CSU

See channel service unit (CSU) (page 27).

CTC mode

See common transmit clock (CTC) mode (page 31).

CTD

See cell transfer delay (CTD) (page 27).

CUG

See closed user group (CUG) (page 28).

cumulative administrative weight (CAW)

Sum of the connection segment costs across the rerouting domain.

current cell rate (CCR)

The cell rate at which ATM elastic connections are operating when they are not running at full capacity (in a reduced bandwidth state). When an elastic connection is operating at full capacity, its CCR is equal to its equivalent cell rate (ECR).

customer edge device or router (CE)

A router or device that is part of a customer network and that interfaces to a provider edge (PE) router.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 38 -

List of terms

customer identifier (CID)

The customer identifier is used in customer network management (CNM) to limit the user’s access to components that belong to the same customer identifier. A CNM operator can send commands only to components provisioned with the same CID as the operator. A CNM operator receives only data collection system (DCS) data, such as alarms, that is generated by components provisioned with the same CID as that of the operator. The special CID of 0 is reserved for the network owner, known as the network manager (Netman). A CID of zero is required to provision the overall network.

customer network management (CNM)

Allows virtual private network (VPN) user access to VPN-specific information, such as real-time alarms and the use and status of VPN network components and shared components.

D-channel

See delta channel (D-channel) (page 41).

One of the framing patterns for DS1, in which there are 12 frames for each multiframe. See also

extended superframe (ESF) (page 50).

data circuit-terminating equipment (DCE)

In data communications, the equipment at the network side of a subscriber link that provides both interface control and the means of digital transmission between user premises and the network nodes.

data collection system (DCS)

A software system that collects various types of management data (such as alarms, accounting records, logs, state change notifications, and traps information) and distributes it as requested.

data encryption standard (DES)

A symmetric encryption algorithm standardized by the National Institute of Standards and Technology.

data link connection identifier (DLCI)

Ten bits within the two address octets of a frame relay address header that carry information used to locally identify the virtual circuits or permanent virtual circuits. For more information, see NN10600-900 Nortel Multiservice Switch 7400/15000/20000 Frame Relay Technology Fundamentals.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 39 -

List of terms

data flow preservation

The process of maintaining uninterrupted data flow over a sequence of potentially disruptive events. Connection preservation is implied whenever data flow is preserved. Data flow preservation does not guarantee that data is never discarded (for example, due to either congestion or error conditions).

See connection preservation (page 34).

data link control (DLC)

An interface that provides logical link control connection services.

data link switching (DLSw)

A forwarding protocol for wide area network support of the NetBIOS protocol.

data manipulation engine (DME)

The data manipulation engine (DME) is the base service that provides capabilities for moving data frames to/from link interfaces and between function processors within a Nortel Multiservice Switch node. It is designed to provide protocol-based applications with the capability of performing operations on data frames. Such operations are packet header manipulation, packet retransmission, timing events, and queuing.

data network address (DNA)

A DNA is an identifier given to applications in many data networks. This address is used as the fundamental identifier for setting up a virtual circuit between data networks.

data packet network

A standards-based data networking system for interconnecting diverse host, application, and end-user environments. The system gives organizations the ability to choose the best solutions for data networking. DPN-100 addresses the needs of organizations for reliable multi-protocol data services, such as frame relay, SNA, and X.25, at speeds up to T1/E1. It supports a wide range of physical interfaces including V.24, V.35, V.36, X.21, G.703, and token ring. The highest possible availability, 99.999%, is achieved through networking features, built-in redundancy, and a modular design.

data path object (DPO)

A data path object is a C++ object that processes frames at the interrupt level on a Nortel Multiservice Switch card. A frame processes by passing through a chain of DPOs; each DPO returns the ID of the next DPO in the chain. You can configure a DPO to be addressable module-wide.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

List of terms

data path object environment

A data path object environment is one of the two programming environments that are extensions of the operating system. The data path object environment supports the functions of Nortel Multiservice Switch network services, that is, functions that associate with data path processing.

data service unit (DSU)

A type of interface used to connect a terminal to a digital medium. In most cases, it is used in conjunction with a CSU. Refer to

(CSU) (page 27) for details.

data terminal equipment (DTE)

The name used to designate the user equipment on a subscriber link.

data type

A division of information with common qualities that affect their representation and semantics (for example, numbers or strings). Data types are used to represent values in component instances, component attributes, verb options, response attributes. They are used as index values within replicated, vector, and array attribute types. The component model supports the following data types and variations: array, ASCII string, binary-coded decimal (BCD), component name, compound, dashed hex string, decimal, enumeration, extended ASCII string, hex number, hex string, IP address, link, list, long, null, replicated, integer sequence, set of bits, signed, time, fixed-point decimal, vector, and wild-carded BCD.

- 40 -

channel service unit

For more information on each attribute type, see the appendix on attribute types in NN10600-060 Nortel Multiservice Switch 7400/15000/20000 Component Reference.

DBNL

See dial backup network link (DBNL) (page 41).

DBR

See domain-based rerouting (DBR) (page 43).

DCE

See data circuit-terminating equipment (DCE) (page 38).

DCS

See data collection system (DCS) (page 38).

See discard eligibility (DE) (page 42).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 41 -

List of terms

See designated router (DR) (page 41).

default gateway

The gateway used to reach a destination if no other route is known or provided.

Defense Network Secure Information Exchange (DNSIX)

A protocol defined in RFC 1038 and RFC 1108 for passing confidential data securely over a network.

delta channel (D-channel)

A bidirectional channel, also known as the D-channel, used to carry call control messages and signaling information over ISDN links.

designated router (DR)

When a LAN has multiple multicast routers attached, one of the routers is elected as the router designated to forward the multicast traffic.

designated transit list (DTL)

A list of node and link identifiers that completely specify a path across a single PNNI peer group. Link identifiers are optional.

device alarm

An alarm that originated from a device (for example, a Nortel Multiservice Switch node).

DGCRA

See dynamic generic cell rate algorithm (DGCRA) (page 45).

dial backup network link (DBNL)

A type of dial-in DPN gateway providing connectivity when a dedicated connection breaks.

dial-in DPN gateway

A connection made by modem between a DPN module and a Nortel Multiservice Switch node. The network link type is dial backup.

DiffServ

A Nortel Multiservice Switch IP differentiated service feature that provides IP traffic management.

DiffServ domain

A group of virtual routers that are using the same per-hop-behavior

(page 101) definitions to apply differentiated services to IP traffic.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 42 -

List of terms

differentiated services code point

A 6-bit field in an IP packet header that is used for specifying differentiated service parameters for the IP packet.

Digital Private Network Signaling System No 1 (DPNSS 1)

A common-channel signaling protocol intended for use between PBXs in private networks through time slot 16 of a 2.048 Mbit/s digital transmission system. Similarly, it can be used through time slot 23 of a 1.544 Mbit/s digital transmission system.

DIN

Deutsche Industrialische Norm. A set of standards for electronic and industrial products that originated in Germany.

Dijkstra’s algorithm

An algorithm that is sometimes used to calculate routes in an ATM network, given a link and nodal state topology database.

direct memory access (DMA)

A method of transferring data to or from memory without having to use the CPU, thus improving the overall speed of the system.

discard eligibility (DE)

A bit in the frame relay header. A frame is marked with the DE bit to indicate that, in times of congestion, the frame is to be discarded before frames without the DE bit set. This bit is set either by the user or the network.

discard priority (DP)

Discard priority refers to the importance of a frame or cell. The Nortel Multiservice Switch system has 4 discard levels, where 0 is the most important (last to be discarded) and 3 is the least important (first to be discarded). Discard priority 0 is reserved for Multiservice Switch control traffic, leaving three discard priorities for user traffic.

DLCI

See data link connection identifier (DLCI) (page 38).

DLSw

See data link switching (DLSw) (page 39).

DMA

See direct memory access (DMA) (page 42).

DME

See data manipulation engine (DME) (page 39).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

List of terms

DNA

See data network address (DNA) (page 39).

DNSIX

See Defense Network Secure Information Exchange (DNSIX) (page 41).

domain

See PNNI routing domain (page 103).

domain-based rerouting (DBR)

An ATM Forum standard protocol that enables the PNNI network to employ a rerouting mechanism that protects a connection segment within one or more local rerouting domains.

double-ended accounting

Accounting records are generated at both the ingress and egress ends of the connection. This option is available for both frame relay and ATM accounting features. BothEnds is another term for a double-ended accounting record for frame relay accounting. Double-ended accounting is recommended for ATM accounting over single-ended accounting to ensure the records reflect the actual amount of data transported from end to end.

- 43 -

downspeeding

In bit-transparent data service (BTDS) software, the capability of decreasing the data rate by adjusting the physical clock speed of the line in response to congestion.

DPN

See data packet network (page 39).

DPN gateway

A Nortel Multiservice Switch node-to-DPN connection. Its provisioning is similar to that of a Multiservice Switch trunk.

DPN routing

See dynamic packet routing system (DPRS) (page 45).

DPNSS 1

See Digital Private Network Signaling System No 1 (DPNSS 1) (page 42).

See discard priority (DP) (page 42) and drop precedence (DP) (page 44).

DPO

See data path object (DPO) (page 39).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

DPRS

See dynamic packet routing system (DPRS) (page 45).

DRAM

Dynamic random access memory.

drop precedence (DP)

Drop precedence refers to the importance of an IP packet. A drop precedence value is assigned to a packet to control its loss sensitivity relative to other packets when they are placed on the same queue. Generally, a drop precedence value of low indicates the packet is less likely to be discarded when the queue is congested. This traffic has a higher probability of being forwarded. Similarly, a drop precedence value of high indicates the packet is more likely to be discarded when the queue is congested. This traffic has a lower probability of being forwarded. The actual loss sensitivity of packets depends on the discarding mechanism at the queue.

- 44 -

List of terms

DS0

DS1

DS1c

DS3

DSCP

DSU

DTE

The 64 kbit/s line standard format for North America as defined by the ITU-T.

The 1.544 Mbit/s interface defined in ITU-T G.703. Consists of a framed pattern of twenty-four 64 kbit/s time slots.

A digital signal level having a transmission rate of 3.152 Mbit/s carrying

DS0s plus overhead bits.

The 44.736 Mbit/s line standard format in North America as defined by the ITU-T. This is the format used to carry information over the T3 trunk.

See differentiated services code point (page 42).

See data service unit (DSU) (page 40).

See data terminal equipment (DTE) (page 40).

DTL

See designated transit list (DTL) (page 41).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

DTL originator

The first lowest-level node within the entire PNNI routing domain to build the initial DTL stack for a given connection.

DTL terminator

The last lowest-level node within the entire PNNI routing domain to process the connection (and thus the DTL for the connection).

DTMF

See dual tone multi-frequency (DTMF) (page 45)

dual-bus mode

A configuration in which both backplane buses are available to carry cells between operational cards.

dual fabric mode

A configuration in which both backplane fabric cards are available to carry cells between operational cards.

- 45 -

List of terms

dual-FP line APS

A type of implementation scheme that uses two optical interface cards to provide SONET or SDH line automatic protection switching. Dual-FP APS allows equipment sparing for optical interface cards.

See automatic protection switching (APS) (page 15).

dual leaky bucket

See inverse-UPC shaping (page 68).

dual tone multi-frequency (DTMF)

A signalling method that uses specific pairs of frequencies within the voice band for signals.

dynamic generic cell rate algorithm (DGCRA)

A version of the GCRA. DGCRA uses information supplied by ABR.

dynamic packet routing system (DPRS)

A connectionless routing system for delay-sensitive and high-throughput variable bit rate traffic. DPRS carries data traffic such as frame relay and all DPN-100 services such as X.25.

The 2.048 Mbit/s interface defined in ITU-T G.703. Usually consists of a framed pattern of thirty-two 64 kbit/s time slots.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

The 34.368 Mbit/s interface defined in ITU-T G.703 and G.704.

E.164

The ITU-T recommended numbering plan for ISDN that includes the numbering plan for public switched telephone networks.

early packet discard (EPD)

EPD is a feature that applies a more stringent discard policy to the first cell of an AAL-5 frame than it does to subsequent cells. This reduces the number of incomplete frames in the network and thereby increases the throughput.

EAP

See external address plan (EAP) (page 51).

EBGP

See external border gateway protocol (EBGP) (page 51).

- 46 -

List of terms

EBR

1 See edge-based rerouting (EBR) (page 46).

2 See equivalent bit rate (EBR) (page 49)

echo cancellation

A technique in voice networking that allows for the isolation and filtering of unwanted signal energy caused by echoes from the main transmitted signal.

ECR

See equivalent cell rate (ECR) (page 49).

edge-based rerouting (EBR)

Edge-based rerouting refers to procedures used in a PNNI network to recover and optimize active point-to-point SVC, SVP, soft PVC, and soft PVP connections.

EFCI

See explicit forward congestion indication (EFCI) (page 50).

See external gateway (EG) (page 51).

EGP

See exterior gateway protocol (EGP) (page 51).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

egress accounting

A method of collecting information based on customer use of network resources. The information is used by the service provider to develop billing policies and quality of service parameters. As the name implies, this information is collected at the exit (egress) points of the network for each frame relay data link connection (DLC).

egress node

The last Nortel Multiservice Switch node that processes the packet as it traverses the Multiservice Switch network; that is, the node from which the packet exits the Multiservice Switch network.

See also ingress node (page 64) and tandem node (page 132).

egress protocol

The egress protocol synchronizes the accounting meters at the opposite ends of the connection and facilitates the exchange of data collected by the accounting meters.

- 47 -

List of terms

egress traffic

Egress traffic refers to the traffic exiting from a Nortel Multiservice Switch network through an access point.

EIR

See excess information rate (EIR) (page 50).

elastic connection

An ATM connection type that is able to respond to changes in bandwidth over an ATM link through a decrease or an increase in its contracted data rate.

See enterprise module (EM) (page 48).

emission priority (EP)

Traffic management mechanism used to handle delay requirements of different types of traffic. Emission priority grading is implemented in three emission queues, interrupting, high, and normal, which are serviced in that order. The interrupting queue is typically used for CBR traffic, such as voice and BTDS. The high and normal priority queues are used for VBR traffic, such as frame relay. This queue arrangement allows delay-sensitive cells, such as voice and video, to interrupt the transmission of long data frames, such as frame relay. (In ATM FPs, there is no interrupting queue, since multiplexing is already occurring at the cell level. The queues are known as high, medium, and normal.)

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

A class scheduler uses emission priority to determine relative importance between service classes for the purpose of determining which service class data is forwarded to the next queue.

end of message (EOM) cell

The last cell in a series of cells that result from segmentation of higher-layer packets or frames. The EOM cell marks the last cell in the cell series that represents one packet or frame.

endpoint (EP)

The software managing the subscriber access point. The endpoint can include the software for the access service, the virtual channel or path, or the logical connection.

end system

A system on which connection termination points are located.

- 48 -

List of terms

end-to-end connection

The entire connection within the PNNI network from the PNNI source node to the PNNI destination node.

enterprise module (EM)

The root-level component of Nortel Multiservice Switch node. Its instance value is the node name.

entry border node

The node that receives a call over an outside link. This node is the first within a peer group to see the call.

EOM

See end of message (EOM) cell (page 48).

1 See endpoint (EP) (page 48).

2 See emission priority (EP) (page 47).

EPD

See early packet discard (EPD) (page 46).

equipment sparing

Switching service functionality from failed hardware to equivalent standby hardware. For CPs and FPs, one-for-one sparing enables a spare processor card to stand by for an equivalent single main processor card. One-for-n sparing enables a spare processor card to stand by for “n” main processor

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

cards. One-for-n FP sparing requires a sparing panel and only applies to electrical FPs (copper-based as opposed to fiber optical). See also

(page 125).

equivalent bit rate (EBR)

The bandwidth (in bit/s) that the network reserves for a FR-ATM connection. The EBR or requested bandwidth computation for each connection request determines the CAC mechanism.

equivalent cell rate (ECR)

The bandwidth (in cell/s) that the network reserves for a particular ATM connection.

See explicit rate (ER) (page 50).

- 49 -

List of terms

spare card

ESD jack

A jack located on the Nortel Multiservice Switch node for plugging in an antistatic wrist strap to protect the hardware against electrostatic discharge.

ESF

See extended superframe (ESF) (page 50).

Ethernet

A physical and data link layer protocol that follows the IEEE 802.3 standard or the related Xerox, Digital, and Intel Ethernet standard.

Ethernet address

A 48-bit media access layer (MAC) address composed of an assigned sixoctet manufacturer’s code and a unique number (such as a serial number) provided by the manufacturer.

ETSI

European Telecommunications Standards Institute. A telecommunications standards body.

ETSI QSIG

European Telecommunications Standards Institute Q interface signaling. A common channel signaling protocol supported by the Nortel Multiservice Switch Voice Networking service.

European digital subscriber signaling system number one (EDSS1)

A common channel signaling protocol supported by the Nortel Multiservice Switch Voice Networking service.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 50 -

List of terms

excess burst size (Be)

The amount of data (in bits) that a network agrees to transfer over a measured interval if network bandwidth is available.

excess information rate (EIR)

The sustainable rate of data transfer in excess of CIR that the network delivers if there is available bandwidth. It is related to excess burst (Be) and measurement interval (T) as EIR = Be/T.

exit border node

The node that progresses a call over an outside link. This node is the last within a peer group to see the call.

explicit forward congestion indication (EFCI)

An indicator that an ATM network element can set in a cell header to indicate pending or current network congestion. End system applications can read this indicator and reduce transmission requirements, which in turn reduces network congestion over time. EFCI is a reactive traffic management strategy. Not all applications can read the EFCI and respond accordingly.

Also, a function of ABR through which nodes indicate the presence of local congestion by setting a bit in traffic cells.

explicit rate (ER)

A function of ABR whereby nodes deposit an explicit cell rate offer in a BRM cell based on the current rate and locally determined congestion.

export policy

A collection of rules that govern the distribution of route information. These policies are used by the BGP, EGP, OSPF, and RIP route management protocols.

extended superframe (ESF)

One of the framing patterns for a DS1 line consisting of 24 frames for each superframe. See also

D4 (page 38).

exterior

In PNNI networking, a term that indicates that an item (such as a link, node, or reachable address) is outside of a PNNI routing domain.

exterior link

A link that crosses the boundary of the PNNI routing domain. The PNNI protocol does not run over an exterior link.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 51 -

List of terms

exterior reachable address

An address that a node can reach through a PNNI routing domain but that is not located in that PNNI routing domain.

external address plan (EAP)

An address plan that is not the Nortel Multiservice Switch internal address plan. Examples of EAPs are a DPN internal address plan and an IP address plan.

external border gateway protocol (EBGP)

BGP configuration in which sessions are established between routers in different autonomous systems (ASs). See also

(BGP) (page 20) and multi-hop BGP (page 83).

external gateway (EG)

A connection to a non-Nortel Multiservice Switch external module (for example, a connection to a DPN-100 module).

border gateway protocol

exterior gateway protocol (EGP)

An IP routing protocol that operates between autonomous systems on the Internet. BGP-4 is replacing EGP.

external routing protocol

A routing protocol from another network. Routing of external protocols is done either natively or using encapsulation. External protocols are routed natively when the packet is routed directly according to the address contained in its header. Encapsulation is used to completely envelop the external protocol within a Nortel Multiservice Switch packet, using it for making routing decisions.

fabric card

The circuit pack that performs the cell-switching activities between the processor cards of a Nortel Multiservice Switch Switch

20000 node.

fabric port

An interface to the fabrics of a Nortel Multiservice Switch 15000, or Multiservice Switch

20000 node.

facsimile handling

The handling of in-band facsimile or modem data dynamically. On detection of a facsimile or data call, echo cancellation is disabled and the voice compression rate is adjusted to allow the facsimile or data information to be transported to its destination.

15000, or Multiservice

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 52 -

List of terms

fair buffer allocation (FBA)

Guarantees that connections or classes receive a fair portion of the total available cell buffers in a function processor.

FAS

See frame alignment signal (FAS) (page 54).

fast management information protocol (FMIP)

The proprietary fast management information protocol (based on OSI/ASN.1 principles) implemented between a Nortel Multiservice Switch node and Nortel Multiservice Data Manager workstation, to manage the node.

FAX handling

See facsimile handling (page 51).

fax idle suppression (FIS)

A function performed by Nortel Multiservice Switch nodes when processing facsimile transmissions, which saves bandwidth by not transmitting the idle portions between data bursts. During a typical facsimile transmission, FIS can reduce bandwidth use by as much as 20 percent in the sending direction and 80 percent in the receiving direction.

fax relay

A modulation/demodulation technique used by the voice transport service for transmitting facsimile traffic across a Nortel Multiservice Switch network. The types of modulation supported are based on ITU-T recommendations V.27 (up to 4.8 kbit/s) and V.29 (up to 9.6 kbit/s). Fax relay is only supported on MVPE FPs.

FBA

See fair buffer allocation (FBA) (page 52).

FCI

See forward congestion indication (FCI) (page 54).

feature

Nortel Multiservice Switch applications consist of features (for example, frame relay UNI is a feature of the frame relay application). Each processor card is provisioned to run a set of features.

feature list (FL)

The list of provisionable features that can be loaded onto a processor. The feature list is a provisionable attribute of a logical processor type.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

FECN

See forward explicit congestion notification (FECN) (page 54).

file

A set of related records that are treated as a unit for the purposes of storage and retrieval.

file prober

Software residing on the Nortel Multiservice Data Manager workstation that uses FTP to transfer accounting data from the Nortel Multiservice Switch node to the host computer.

file transfer protocol (FTP)

A TCP/IP protocol used to transfer files across an internet. See also Internet protocol interface over virtual circuit (IPIVC).

- 53 -

List of terms

filter

filtering

FIS

FLM

FMI

FMIP

A subroutine for discriminating among packets. Filters are used to decrease traffic or improve security over network interfaces.

In the context of using commands such as list, display or find, filtering is an operation that decreases the number of components targeted by a command.

See fax idle suppression (FIS) (page 52).

See feature list (FL) (page 52).

See frame link monitoring (FLM) (page 55).

See frame mode information (FMI) (page 55).

See fast management information protocol (FMIP) (page 52).

FMIP enclosed

Format type associated with Nortel Multiservice Switch system accounting and statistics records. FMIP enclosed accounting and statistics records are raw data records that are enclosed in FMIP headers and trailers.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 54 -

List of terms

foreign address

An address or address prefix that does not match the summary addresses provisioned on any given node.

forward congestion indication (FCI)

A bit in the Nortel Multiservice Switch common header set to indicate that congestion was experienced by packets travelling through the Multiservice Switch network. Congestion in the subnet and at the access is indicated by BCI/FCI bits. The frame relay service at the node evaluates frames from the subnet for BCI/FCI bit indications, and based on this, sets the appropriate BECN/FECN bit on the frame sent to the user.

forward explicit congestion notification (FECN)

The FECN bit is used in the frame relay header of a frame to warn the receiving-end device that the frames it is receiving (traveling in the same direction) have encountered congestion or congested resources.

forward resource management cell (FRM)

Resource management cells that an ABR source sends to its destination. See

resource management (RM) cell (page 113).

See function processor (FP) (page 57).

frame

A variable length data unit, with an associated control header, that is transmitted across the network. The frame header determines the destination of the frame and carries sequencing and error detection information. Many frames are required to carry a complete document or message.

frame alignment signal (FAS)

A sequence of signal bits used for synchronizing E3 frames.

frame-cell trunk

The transport mechanism used by Nortel Multiservice Switch trunks to carry both frame and cell traffic on a frame-based interface.

HDLC mode is a provisionable mode in which a frame-cell trunk can operate and use HDLC framing.

Interrupting mode is a provisionable mode in which a frame-cell trunk can operate and use a modified HDLC-based framing. Interrupting mode allows highest priority data to interrupt traffic less sensitive to delay or traffic with a lower emission priority.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

frame link monitoring (FLM)

Provides the ability to distinguish between physical line failure and customer premises equipment failure in the case of a system failure at the access to a Nortel Multiservice Switch frame relay node.

framed protocol

A set of formal rules describing how to transmit frames. HDLC framing uses a standard protocol for the sequential transmission of individual frames. Interrupting framing uses a modified-HDLC format that allows voice cells to interrupt the transmission of data frames, transmit the voice cell, and continue transmitting the data frame.

Framer

The Framer component controls link layer framing for application components sending and receiving data on a link interface. For frame relay applications, it is also through Framer that an application component is associated with a specific hardware link interface.

- 55 -

List of terms

frame mode information (FMI)

The system responsible for maintaining the Nortel Multiservice Switch nodeto-node connections. For example, FMI supports the following connections: Multiservice Switch node-to-Multiservice Switch node, Multiservice Switch node-to-DPN-100 access module, Multiservice Switch node-to-DPN-100 resource module.

frame relay IP server

A logical representation that allows multiple IP-enabled FrUnis on the same function processor to share a single protocol port on the virtual router.

frame relay multiplexor/demultiplexor

A Nortel Multiservice Switch component that can distinguish traffic from multiple frame relay peers for distribution to multiple applications in a Multiservice Switch node.

frame relay managed cut-through switching (MCS)

A feature that provides bidirectional, point-to-point virtual connections between Nortel Multiservice Switch nodes at a specific quality of service (QOS). The MCS connection is a switched path that provides many-to-one multiplexing of connections for a data service.

frame relay service (FRS)

A streamlined ISO data link layer protocol. A frame relay network supports only core communications functions (such as transparency, multiplexing, and orderly delivery). This simplified processing (as opposed to traditional packet data protocols) permits higher speeds and lower delays for a given processing capability. Simplification is made possible by the assumed use of improved

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 56 -

List of terms

transmission facilities (high-quality digital facilities), which are affected by far fewer transmission errors. Furthermore, many functions such as sequencing flow control and retransmission are performed by end user equipment.

Frame relay-to-ATM interworking function (FR-ATM IWF)

A Nortel Multiservice Switch frame relay service that provides interworking functions between frame relay PVCs and ATM PVCs using AAL-5.

See also, FR-ATM interworking service (page 56).

FR-ATM accounting

An accounting service that collects usage information (byte and frame counts) on FR-ATM connections. Service providers can use this information to bill their customers, or for test, statistics, network engineering, and planning purposes.

FR-ATM gateway

An application of the FR-ATM interworking service that converts frame/cell traffic to and from ATM cell traffic. The FR-ATM gateway provides a frame relay interface (either UNI or NNI) that converts frame relay traffic coming in from its link into cells leaving the node at an ATM interface. In the other direction, the gateway converts cell traffic coming into the node at the ATM interface to frame relay traffic going out on the frame relay UNI or NNI. The FR-ATM services frame relay traffic originating across the frame/cell subnet.

FR-ATM interworking service

The FR-ATM interworking service allows the carriage of frame relay traffic over an ATM networking and transport infrastructure. It maps frame relay permanent virtual circuits (PVCs) to and from ATM PVCs to provide connectivity between frame relay CPE and ATM-capable CPE. The FR-ATM interworking service comprises a core frame relay UNI/NNI service and an interworking function.

The FR-ATM interworking supports the application of the FRF.8 standard for service interworking (SIWF) and the FRF.5 standard for network interworking (NIWF).

free list

The part of the shared memory that is currently unused and available for data arriving into the FP card.

free list size

The number of blocks that currently make up the free list.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

free list threshold

A free list threshold is a specific number of blocks used in the determination of the congestion state of the free list. A free list can define several thresholds. As the free list size crosses each threshold, the free list enters a more severe congestion state. For example, ATM FPs define three free list thresholds. The free list at its maximum size starts off in congestion state 3; and as it is depleted and falls below the first threshold, it enters congestion state 2.

FRIP

See frame relay IP server (page 55).

FRM

See forward resource management cell (FRM) (page 54).

FRS

See frame relay service (FRS) (page 55).

- 57 -

List of terms

FTM

The Nortel Multiservice Switch traffic management system. It detects congestion and reports it to the service (frame relay, for example).

FTP

See file transfer protocol (FTP) (page 53).

full FMIP

Format type associated with Nortel Multiservice Switch system accounting and statistics records. For full FMIP accounting and statistics records, each field is completely encoded in FMIP format.

function processor (FP)

A type of processor card that supports physical interface connections to subscriber lines and network trunks. It is optimized to support the software that performs the real-time functions associated with the forwarding and routing of frames. Different types of FPs support different types of physical interfaces, such as DS1, E1, V.35, and V.11 access and trunks. See also

control processor (CP) switchover (page 35).

G.711

ITU-T standard related to pulse code modulation (PCM) of voice frequencies.

G.729

ITU-T standard related to coding of speech at 8 kbit/s using conjugatestructure algebraic-code-excited linear-prediction (CS-ACELP).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

gateway

1 See accounting gateway (page 6).

2 See DPN gateway (page 43).

3 See external gateway (EG) (page 51).

4 See FR-ATM gateway (page 56).

5 See gateway identifier (GID) (page 58).

6 See internal gateway (page 66).

7 See X.25 gateway (page 149).

8 See X.75 gateway (page 149).

gateway identifier (GID)

An integer that uniquely identifies an X.25 gateway or an X.75 gateway in a network.

- 58 -

List of terms

GCRA

See generic cell rate algorithm (GCRA) (page 58).

general packet radio service

A packet-linked technology that enables high-speed, 115-kbit/s, wireless Internet, and other data communications.

general virtual circuit interface (GvcIf)

GvcIf is a networking feature providing circuit establishment between LAN/ WAN services.

generic cell rate algorithm (GCRA)

An algorithm used in a Nortel Multiservice Switch ATM network to monitor and police network traffic. In Multiservice Switch traffic management, GCRA is used by usage parameter control (UPC) to enforce conformance at the source ATM terminal.

generic flow control (GFC)

A four-bit field in the ATM cell header at a user-to-network interface intended for traffic flow control between the user and network equipment.

generic queue manager (GQM)

A traffic management device (ASIC) which resides on GQM function processor (FP) cards. The GQM descends from other traffic management devices such as the AQM and QRD, and is capable of OC-48. It differs considerable from the other traffic management devices in that it will schedule up to a single OC-48 channel, its scheduling algorithms are frame or cell

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 59 -

List of terms

agnostic, it can shape four emission priorities (EPs), and it does not have a usage parameter control (UPC) function because that is done by a different ASIC called ATLAS (on the same card).

global rerouting domain

In the context of the global rerouting protocol, the entire set of nodes in the PNNI network including all nodes belonging to all local rerouting domains.

Global System for Mobile Communications

A standard digital cellular phone service used in Europe and Japan, to ensure interoperability between countries.

good-put

In an ATM network, the measurable amount of traffic that is transmitted from source to destination that can be successfully segmented and reassembled by the end systems. A high good-put means that few or no cells were transmitted that could not be reassembled into frames.

GPRS

See general packet radio service (page 58)

group address

In ATM networking, identifies a group of endstations. The ATM group address is characterized by the group address AFI. The ATM groups and AFIs are defined in the ATM Forum User-to-Network Interface Signaling Specification Version 4.0 (af-sig-0061.000), Annex 5.

GQM

See generic queue manager (GQM) (page 58).

GSM

See Global System for Mobile Communications (page 59).

GvcIf

See general virtual circuit interface (GvcIf) (page 58).

H.248

The ITU-T gateway control protocol. H.248 is one control interface used between the media gateway controller and the Media Gateway.

half session (HS)

A session-layer component consisting of the combination of data flow control and transmission control components comprising one end of a session.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 60 -

List of terms

hard rerouting

See connection recovery (page 33).

HDB3

See high-density binary 3 zero maximum encoding (HDB3) (page 60).

HDLC

See high-level data link control (HDLC) (page 61)

HDLC mode

See frame-cell trunk (page 54).

HDLC-transparent data service (HTDS)

A service that transports HDLC-framed data across the network without interpretation, except that interframe flags are not transmitted. The efficiency of the transmission is increased by not transmitting flags.

header error control (HEC)

A CRC code found in the last byte of the ATM cell header that is used for verifying cell integrity.

hello packet

A type of PNNI routing packet that neighboring logical nodes exchange.

Hello protocol

The Hello protocol is a neighbor discovery protocol run over private networkto-network interface (PNNI) links between lowest level nodes and logical group nodes (LGNs).

HEP

See hot equipment protection (HEP) (page 62).

See hunt group (HG) (page 62).

hierarchically complete source route

A stack of DTLs that represent a route across a PNNI routing domain. A DTL is included for each hierarchical level between and including the current level and the lowest visible level in which the source and destination nodes are reachable.

high-density binary 3 zero maximum encoding (HDB3)

An encoding technique used to transfer bits over E1 and E3 lines. To ensure 1’s density, HDB3 substitutes a bipolar violation where four or more 0s are to be sent in a row.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 61 -

List of terms

high-level data link control (HDLC)

An ITU-TSS link layer protocol standard for point-to-point and multipoint communications.

high-speed serial interface (HSSI)

An EIA/TIA-613 physical layer standard. Similar to V.35 and V.11, HSSI is an interchange circuit that transfers serial data between DTE and DCE at speeds ranging from 1 Mbit/s to 52 Mbit/s.

hitless CP switchover

The switch of activity from the active CP to a standby CP without restarting the FPs on the shelf. FPs that support hitless CP switchover continue, uninterrupted, to provide service. FPs that do not support hitless CP switchover must restart and do not provide uninterrupted service.

hitless services

1 A service is hitless when the software that provides the service can run

uninterrupted, even when the hardware providing the service changes. With hitless services, traffic incurs minimal interruption and established connections stay up. Nortel Multiservice Switch software applications and features are categorized based on their ability to provide hitless services.

2 See cold standby (page 30).

3 See hot standby (page 62).

4 See warm standby (page 148).

hitless software migration (HSM)

Hitless software migration allows a shelf (CPs and FPs) to migrate from one version of software to another without interrupting the services being provided by that shelf.

holding priority (HP)

In an ATM network, a priority scheme that is assigned to all bandwidth nonelastic ATM connections to indicate the relative importance of each connection. When a loss of bandwidth occurs, connections with lower holding priority are released first.

In a PORS network, a parameter that indicates the tolerance of a connection for path bumping. A connection with a lower holding priority can be bumped to an alternative path or terminated by a connection with a higher priority.

hop by hop route

A routing approach in which each node along the path uses its own routing knowledge to determine the next hop of the route. The expectation is that all nodes choose consistent hops so that the call reaches the requested destination.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

List of terms

hop count

The number of hops it takes for a packet to make it from a source to a destination, that is the number of nodes (routers) between a source and a destination. Each switch or router traversed by a packed is considered a hop.

horizontal link

A link between two logical nodes that belong to the same peer group.

host computer

The central controlling computer in a network of computers. It allows lowerlevel terminals to work through it to obtain access to other computers and their stores of information.

hot equipment protection (HEP)

A carrier grade feature that provides a customer with the capability of setting up a sparing configuration that allows for hitless switch-over capabilities.

- 62 -

hot standby

Hot standby applications and features offer hitless services during an FP or CP switchover. During an equipment switchover, hot standby applications incur minimal traffic interruption and established connections stay up.

hot swapping

Hot swapping of a data path refers to a service switchover while the node is in service.

See holding priority (HP) (page 61).

See half session (HS) (page 59).

HSM

See hitless software migration (HSM) (page 61).

HSSI

See high-speed serial interface (HSSI) (page 61).

HTDS

See HDLC-transparent data service (HTDS) (page 60).

hunt group (HG)

Hunt groups are a group of network addresses (DNAs) reachable from a unique DNA and configured so that an incoming call automatically searches for an available address in the group.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

I80960

IAD

IBGP

ICR

ICMP

- 63 -

List of terms

A 32-bit Intel embedded processor that is one of the processing engines of control processors and function processors. It coordinates all activity on these processor cards.

See Integrated Alarm Display (IAD) (page 65).

See internal border gateway protocol (IBGP) (page 66).

See initial cell rate (ICR) (page 64).

See Internet control message protocol (ICMP) (page 67).

IGMP

See Internet group management protocol (IGMP) (page 67).

IGP

See interior gateway protocol (IGP) (page 66).

IISP

See interim interswitch signaling protocol (IISP) (page 66).

IMA

See inverse multiplexing for ATM (IMA) (page 68).

IME

See interface management entity (IME) (page 65).

IMA link group

See link group (LG) (page 73).

IMUX

See inverse multiplexing for frame relay (IMUX) (page 68)

import policy

A collection of rules that govern the reception of route information. These policies are used by the BGP, EGP, and RIP route management protocols.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 64 -

List of terms

in-band synchronization

The process through which the accounting system takes a simultaneous snapshot of the accounting data at each end of the virtual circuit. This snapshot is used to generate an accounting record.

incumbent segment

An active connection segment that is in the process of being replaced by an alternate connection segment.

independent link

A single physical link used directly by the ATM layer. It is not part of an IMA group.

independent transmit clock (ITC) mode

An IMA configuration in which the transmit clock on one or more physical links in the IMA group is derived from different sources. This is contrasted with common transmit clock (CTC) mode.

independent VCC

A VCC that is not associated with a virtual path terminator.

induced uplink

An induced uplink is an uplink that is created by a logical group node (LGN) by aggregating uplinks advertised by its corresponding lower level peer group leader (PGL).

ingress node

1 The first Nortel Multiservice Switch node that decides to which egress

node the data packet is sent.

2 See also egress node (page 47) and tandem node (page 132).

ingress traffic

Ingress traffic refers to the traffic entering a Nortel Multiservice Switch network through an access point.

initial cell rate (ICR)

In ATM ABR networking, the rate at which the ABR source transmits cells, both initially and after an idle period.

inside link

Synonymous with horizontal link. See horizontal link (page 62).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

instance

Information (such as a decimal or a string) appended to the component type. When more than one of a component type exists, they are differentiated by an instance value.

instance type

The data type for a component instance. The null data type is used for nonreplicated components, and the compound data type is used for multi-indexed components.

instance value

The actual component instance value as permitted by its type.

instantiating

In PORS, the process of laying down the path on the selected route. Once the route is selected by the route selector and returned to the source endpoint, the source endpoint starts the procedure of setting up the path.

- 65 -

List of terms

inter-domain link

A PNNI link that connects two nodes that are in different local rerouting domains or a link using a non-PNNI signaling interface such as UNI, IISP, and AINI.

Integrated Alarm Display (IAD)

A Nortel Multiservice Data Manager Advisor tool used to display alarms.

integrated local management interface (ILMI)

A management interface at an ATM interface that consists of a management information base (MIB) on each side of the UNI and an SNMP-based protocol for exchanging information in the MIBs across the UNI.

integrated services digital network (ISDN)

A digital technology that provides combined voice and data services. BRI access to an ISDN switch provides 2B+D (two 64 kbit/s B-channels and one 16 kbit/s D-channel) over an existing copper telephone line.

Out-of-band signaling is sent over the D-channel to request the setup of one of the B-channels (for high-speed data or voice applications) or of the Dchannel for low-speed data (which can be multiplexed with the signaling and other low-speed data applications from other terminals on the same loop).

interface management entity (IME)

The ATM interface over which ILMI is operating.

interface protocol

1 See FMIP (page 53).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 66 -

List of terms

2 See Telnet (page 133).

3 See local management interface (LMI) (page 75).

4 See SNMP (page 123).

interior gateway protocol (IGP)

An Internet protocol used to exchange routing information with an Autonomous System.

interim interswitch signaling protocol (IISP)

IISP provides interconnection between Nortel Multiservice Switch nodes as well as interconnection between Multiservice Switch and non-Multiservice Switch nodes (Nortel Networks-family nodes and devices from other vendors).

internal border gateway protocol (IBGP)

BGP configuration in which sessions are established between routers in the same autonomous systems (ASs). See also

(page 20).

border gateway protocol (BGP)

internal gateway

A DPN logical connection that runs over a Nortel Multiservice Switch trunk interconnecting two Multiservice Switch nodes in different RID subnets. A Multiservice Switch trunk supporting internal gateways continues to operate as a normal Multiservice Switch trunk in supporting non-DPN type of traffic.

internal reachable address

In PNNI networking, an address of a destination point that is directly attached to the logical node that advertises the address.

internal router

A router with all directly connected networks belonging to the same area. There can be internal routers in the backbone area if all of their interfaces are in the backbone.

International Telecommunication Union - Telecommunication Standardization Bureau (ITU-T)

A European standards body formerly called Comité Consultatif International Télégraphique et Téléphonique (CCITT).

Internet

A network of two or more networks. Usually these networks use different governing protocols or are administratively or physically separated.

Internet addressing

A system of addressing using a 32-bit address, usually divided into four octets.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 67 -

List of terms

Internet control message protocol (ICMP)

A collection of error conditions and control messages exchanged by IP modules in both hosts and gateways. Examples consist of echo requests and replies and notification of discarded datagrams.

Internet group management protocol (IGMP)

A protocol that is used between routers and locally attached hosts to communicate multicast group membership information.

Internet protocol (IP)

A protocol suite that operates within the Internet as defined by the requests for comment (RFC). This term can also refer to the network-layer (level 3) of this protocol stack-the layer concerned with routing datagrams from network to network.

Internet protocol interface over frame relay (IPIFR)

Allows a Nortel Multiservice Data Manager workstation to communicate with Nortel Multiservice Switch nodes over frame relay. Once the connection between a workstation and a node has been established, Multiservice Data Manager can connect to the node over frame relay and exchange IP datagrams.

Internet protocol interface over virtual circuit (IPIVC)

In Nortel Multiservice Switch device’s initial releases, FTP, Telnet, Ssh, and FMIP protocols are implemented over TCP/IP protocols using the IPIVC system. This system allows Nortel Multiservice Data Manager workstations to communicate with Multiservice Switch nodes by way of X.25 on DPN-100. Once the connection between a workstation and a DPN-100 module has been established, Multiservice Data Manager can connect to the node over the X.25 virtual circuit and exchange IP datagrams. The ftp connections can be either secure or non-secure as described in the Multiservice Data Manager Security User Guide.

inter-region Multiservice Switch trunk

A Nortel Multiservice Switch trunk that is a link between two border nodes in different topology regions.

interrupting mode

See frame-cell trunk (page 54).

intra-domain link

A PNNI link that connects two nodes that are in the same local rerouting domain.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 68 -

List of terms

inverse multiplexing for ATM (IMA)

A feature available on Nortel Multiservice Switch nodes that supports the transparent transmission of ATM cell data over a link group. IMA transparently distributes a single stream of ATM layer cell traffic onto multiple physical links for transmission across the links, and then combines the traffic back into the original ATM layer cell sequence at the remote end.

inverse multiplexing for frame relay (IMUX)

A frame-based inverse multiplexing function provided by the multilink frame relay (MLFR) service.

inverse-UPC shaping

This form of shaping uses dynamic rate changes so that the resulting cell stream exactly conforms to the requirements of a dual leaky bucket UPC enforcer. Also known as dual-leaky-bucket or VBR shaping.

See Internet protocol (IP) (page 67).

IP address owner

The VRRP router that has the virtual router’s IP address(es) as real interface address(es).

IP class of service (COS)

Provides four different classes of service for different types of IP traffic. With IP COS, you can define a set of policies that identify different types of IP traffic and specify the class of service to pass the IP traffic through the network.

IP COS

See IP class of service (COS) (page 68).

IP multicast forwarding

A packet forwarding mode that delivers IP multicast packets to a group of nodes interested in receiving those packets in an IP network.

IP multicast forwarding table (FWD)

A forwarding table that performs exact match and best match for IP multicast traffic.

IP multicast routing database (RDB)

A routing database for IP multicast traffic.

IP multicast routing table manager (MRTM)

A routing table manager for IP multicast traffic.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

IPSec

A security feature that defines a suite of cryptographic protocols and an architecture used to protect packets at the network layer.

IP tunneling

A feature available on Nortel Multiservice Switch nodes that allows you to connect physically separate IP networks that share the same address space through an IP network on a different address space.

IPIFR

See Internet protocol interface over frame relay (IPIFR) (page 67).

IPIVC

See Internet protocol interface over virtual circuit (IPIVC) (page 67).

Ipv4Label

The BGP address family used for Carrier's Carrier to distribute routes and labels associated with them. It consists of both the address family identifier (AFI) and the subsequent address family identifier (SAFI). Ipv4Label represents the AFI/SAFI value of 1/4.

- 69 -

List of terms

Ipv4MplsVpn

The BGP address family used for BGP/MPLS VPNs to distribute VRF routes and service labels associated with them. It consists of both the address family identifier (AFI) and the subsequent address family identifier (SAFI). Ipv4MplsVpn represents the AFI/SAFI value of 1/128.

ISDN

See integrated services digital network (ISDN) (page 65).

ISO

International Organization for Standardization.

isochronous

A data bit stream that has equal time between bits.

ITC mode

See independent transmit clock (ITC) mode (page 64).

ITU-T

See International Telecommunication Union - Telecommunication

Standardization Bureau (ITU-T) (page 66).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

JT2

A 6312 kbit/s interface defined in TTC JT-G.703. Consists of a framing structure of 789 bits made up of 98 time slots (8-bit) followed by 5 framing bits as defined in TTC JT-G704.

junctor virtual circuit (JVC)

A virtual circuit used to extend the subnet to the legacy data module in a Passport

4400 access unit. The JVC permits the establishment of a general virtual circuit (GVC) connection over a Multiservice Passport access network link (MPANL) service.

JVC

See junctor virtual circuit (JVC) (page 70).

label switching router (LSR)

A core node that performs label switching in an MPLS network.

- 70 -

List of terms

LACP

See “link aggregation control protocol (LACP)” (page 72).

LAG

See “link aggregation (LAG)” (page 72).

LAN

See local area network (LAN) (page 74).

LAPD

See link access procedure on the D-channel (LAPD) (page 72).

LAPF

See link access procedure on frame relay (LAPF) (page 72).

LATA

See local access transport area (LATA) (page 74).

last common node

Network node where the information flow uses an established call/connection to a party at the ingress, and an unused interface at the egress.

late packet discard (LPD)

A packet discard mechanism that works in conjunction with PPD. LPD preserves the end-of-packet cell of a packet that is subject to PPD, which permits identification of the beginning of the subsequent packet.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

layer

In the OSI reference model, a collection of related network processing functions that comprise one level of a hierarchy of functions.

1 See link controller (LC) (page 72).

2 See logical channel (LC) (page 76).

LCN

See logical channel number.

LCo

See logical connection (LCo) (page 76).

LD-CELP

See Low-delay code excited linear prediction (LD-CELP) (page 77).

- 71 -

List of terms

LDS

leaf

LEN

level

LGN

See link delay synchronization (LDS) (page 73).

Is sometimes used interchangeably with party. However, a leaf more accurately denotes any single destination point of a point-to-multipoint call.

See low-entry networking (LEN) node (page 77).

In ATM networking, a level is the position in the PNNI hierarchy at which a particular node or peer group exists. A level that has a smaller numerical value implies greater topology aggregation. Conversely, a level that has a larger numerical value implies less topology aggregation. Smaller numerical values indicate high levels while larger numerical values indicate lower levels.

See link group (LG) (page 73).

See logical group node (LGN) (page 76).

LGN Horizontal Link Hello protocol

The LGN (logical group node) Horizontal Link Hello protocol is a protocol run over an SVCC RCC channel to discover and monitor logical links between neighboring logical group nodes.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 72 -

List of terms

LIF

See loss of IMA frame (LIF) (page 77).

line

1 A dedicated private or leased facility that connects user equipment to the

Nortel Multiservice Switch network. A line can be a link.

2 In SONET, a part of a connection between STS-n multiplexers.

3 In SDH, a part of a connection between STM-n multiplexers.

line automatic protection switching (APS)

1 Automatic protection switching applied to SONET and SDH lines.

Sometimes called linear APS in some specifications, such as Telcordia GR-253.

2 See automatic protection switching (APS) (page 15)

line sparing

See automatic protection switching (APS) (page 15).

link

1 A channel or path between network entities that includes the connection

and the interface devices.

2 A component model data type used to relate non-hierarchical

components. It is represented using an attribute on either component with a value being the other component name. If one side of the link is changed, the other is automatically updated.

link access procedure on frame relay (LAPF)

The data link layer protocol that has been defined for ITU-T Q.921. LAPF is an ISDN access protocol used with links that are established on frame relay.

link access procedure on the D-channel (LAPD)

The data link layer protocol that has been defined for ITU-T Q.921. LAPD is an ISDN access protocol used with links established on a D-channel.

link aggregation (LAG)

Logical grouping of multiple Ethernet links.

link aggregation control protocol (LACP)

This protocol is used to exchange LAG information between two nodes.

link controller (LC)

The integrated circuit (ASIC) that provides a serial data interface into the Nortel Multiservice Switch node.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 73 -

List of terms

link delay synchronization (LDS)

A circumstance in which the receiving end of an IMA link group has measured and compensated for the differential delay over a physical link. If this is the case, then the link is considered to be in link delay synchronization (LDS).

link group (LG)

1 A group of links (Nortel Multiservice Switch trunks or DPN gateways)

between two nodes that can share traffic between the nodes. This allows the available bandwidth between the two nodes to be greater than that of a single link. A maximum of four links in a link group can be supported.

2 An IMA link group refers to the combination of multiple physical links that

use the inverse multiplexing process to transmit traffic across these links. A link group is presented as a single link to the ATM layer. A link group originates on one FP running the IMA feature and terminates on another FP running the IMA feature (typically these FPs are on two different Multiservice Switch nodes). Any link group can be composed of up to eight DS1/E1 physical links on an FP running IMA.

link-level protocol (LLP)

A protocol that permits encapsulation of multiple protocols over a single ATM virtual circuit.

link state advertisement (LSA)

A packet of information that determines the shortest path to a destination.

link-state algorithm

A routing technology in which each node broadcasts to all other nodes its view of the links. When every node in the network does this, all nodes can derive the complete topology and perform operations on that topology.

link state parameter

Information that captures an aspect or property of a link.

live alarm

An alarm that is issued by a fault or other significant event, rather than in response to a replay command.

LLP

See link-level protocol (LLP) (page 73).

LMI

See local management interface (LMI) (page 75).

1 See logical network (LN) (page 76).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 74 -

List of terms

2 See logical node (LN) (page 76).

LNID

See logical node identifier (LNID) (page 76).

LNN

See logical network number (LNN) (page 76).

Load Re-balancing on Parallel Links

When a new Private Network-Network Interface (PNNI) parallel link is added, or an existing PNNI parallel link is dropped and then recovered, the bandwidth is distributed equally across the parallel links.

load sharing

Load sharing is the process by which traffic is divided over links in a link group on a packet by packet basis.

load spreading

If there is more than one equal path to a destination, Nortel Multiservice Switch node’s will pick two of them. Load spreading is the process by which nodes divide traffic, on a VC basis, over the two link groups on those paths and the links in the link group. The algorithm used ensures (under normal conditions) that all the traffic for a given VC follows the same path and uses the same links along that path.

local access transport area (LATA)

Also referred to as a service area by some Bell Operating Companies (BOC), a LATA serves two basic purposes: to provide a method for delineating the area within which the BOCs may offer services and, to provide a basis for determining how the assets of the former Bell System were to be divided between the BOCs and AT&T at divestiture.

The United States has been divided into 200 LATAs by the AT&T Modified Final Judgment. Each BOC may service more than one LATA, but BOCs are generally constrained from providing long distance service between LATAs. Long distance service within a LATA is provided by the LEC. Service between LATAs is provided by an IEC.

local address resolver

A component of connection address resolution (CAR) that performs the resolution of a destination address at the local level.

local area network (LAN)

A network that connects microcomputers, workstations, printers, and other devices together, limited to local distances.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

local bus

A 32-bit bus on a processor module joining local memory (SRAM and DRAM), boot ROM, SBIC, and the microprocessor.

local domain edge node

A node that has at least one inter-domain link.

local domain link type

In the context of the local rerouting protocol, a PNNI link can be described as an intra-domain link or an inter-domain link.

local leaf

Relevant to a single node in a PMP call. A local leaf is on a branch with a local root, across the Nortel Multiservice Switch node back plane, forming a new link to the remote leaf.

- 75 -

List of terms

local management interface (LMI)

In frame relay, the part of the C-plane that manages the PVCs.

local memory

A RAM that stores code and program data for the microprocessor.

local node name

The name of a Nortel Multiservice Switch node. It forms the initial part of all component names, but is usually suppressed. For example, em/ottawa lp/0 appears as lp/0.

local rerouting domain

In the context of the local rerouting protocol, a group of nodes linked by intradomain links.

local root

Relevant to a single node in a PMP call. A local root is on a branch with a local leaf across the Nortel Multiservice Switch node backplane. A local root multicasts copies of incoming cells to each local leaf.

LODS

See loss of delay synchronization (LODS) (page 77).

LOF

See loss of frame (LOF) (page 77).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

logical channel (LC)

A logical division of a Nortel Multiservice Switch trunk that constitutes part of a path. A logical channel is used in a single direction and is locally identified by a logical channel number.

logical connection (LCo)

A logical connection is an association between two endpoints in the Nortel Multiservice Switch network for the purpose of exchanging data.

logical group node (LGN)

An abstract representation of a lower level peer group as a single point for purposes of operating at one level of the PNNI routing hierarchy.

logical link

The combination of logical node identifier and logical port identifier.

- 76 -

List of terms

logical network (LN)

A logical network is a set of Nortel Multiservice Switch nodes and transport facilities (links) that support a particular address plan and packet format. Logical networks allow different customers to set up logically distinct networks using the same physical resources—even the same address scheme, routing protocol, packet formats, and packet forwarding algorithms.

logical network number (LNN)

An identifier for a logical network.

logical node (LN)

A lowest level node or a logical group node.

logical node identifier (LNID)

A string of bits that unambiguously identifies a logical node within a routing domain.

logical port identifier (ID)

Identifies a logical port on the logical node that the connection is to traverse or has traversed.

logical processor (LP)

A body of software that can be mapped to a processor card to deliver one or more Nortel Multiservice Switch services or capabilities. Logical processor-tocard mapping can vary depending on sparing configuration and hardware availability.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 77 -

List of terms

logical processor type (LPT)

Defines the characteristics of an LP. The LPT specifies which software needs to be loaded and provides some processor engineering parameters.

long loop

The ABR VS/VD scenario where FRM cells transit the node to the egress FP before the node turns them around to become BRM cells.

LOS

See loss of signal (LOS) (page 77).

loss of delay synchronization (LODS)

When the delay on a physical link changes such that it exceeds the maximum differential delay specified for the IMA link group, the link is considered to have lost its delay synchronization. That is, the link has experienced a loss of delay synchronization (LODS), and is deactivated from the link group.

loss of frame (LOF)

This failure condition is declared after severely errored frame (SEF) defects have been detected for at least two seconds for a DS1, DS3, E1, or E3.

loss of IMA frame (LIF)

A failure condition in which IMA framing is lost on a link that is part of an IMA link group.

loss of signal (LOS)

For DS1, DS3, E1, and E3, this event is detected at a line interface when 175+/-75 contiguous pulse positions with no pulses of either positive or negative polarity are detected. An LOS failure condition is declared after LOS defects have been observed for at least 2 s.

Low-delay code excited linear prediction (LD-CELP)

A 16 kbit/s compression algorithm used to encode voice data, based on ITU-T

recommendation G.728.

low-entry networking (LEN) node

In Systems Network Architecture (SNA), a physical unit type 2.1 with a control processor does not communicate with other nodes. LEN nodes support logical unit protocols.

lowest level node

A leaf in the PNNI routing hierarchy. A lowest level node is an abstraction that represents a single instance of the PNNI routing protocol. Lowest level nodes are created in a switching system through provisioning and are not created dynamically.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

See logical processor (LP) (page 76).

LP instance

One defined instance of a logical processor. In addition, when a spare card is available, an LP instance can be used to implement equipment sparing.

LPD

See late packet discard (LPD) (page 70).

LPT

See logical processor type (LPT) (page 77).

LRB

See Load Re-balancing on Parallel Links (page 74).

- 78 -

List of terms

LSA

See link state advertisement (LSA) (page 73).

LSR

See label switching router (LSR) (page 70).

MAC

See media access control (MAC) (page 80).

make-before-break rerouting

See path optimization (page 98).

main card

The primary processor card on which an LP is provisioned to run. In a sparing configuration, a main card carries traffic unless a failure causes traffic to switch to a spare card.

MAN

See metropolitan area network (MAN) (page 81).

Management Data Provider (MDP)

The Management Data Provider (MDP) host stores and converts accounting data from DPN-100 and management data (accounting, statistics, alarms, SCNs, and logs) from Nortel Multiservice Switch nodes prior to transferring the data to either a Billing host or a Network Engineering host. The Management Data Provider replaces the Accounting Data Server.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 79 -

List of terms

management data router (MDR)

Collects surveillance data from multiple Nortel Multiservice Switch nodes and distributes it to multiple Nortel Multiservice Data Manager network operation centers.

management information base (MIB)

A database containing configuration and status information relating to a specific managed object or objects. Provides a description of all the components and variables within a component that a network management system can access. It provides the way of naming each of these components and variables. MIB is a concept defined in network management standards such as SNMP.

manual CLR alarm

A CLR alarm issued in response to manual intervention, rather than in response to the system detecting that the associated fault condition no longer exists.

manual path

In path-oriented routing, specifying the series of Nortel Multiservice Switch trunks that form the path instead of letting the system create the path automatically.

marker protocol

A protocol that is used by link aggregation to transfer a conversation from one logical link to another without misordering cells.

maximum burst size (MBS)

One of a set of traffic characterization values used to define traffic characteristics through the traffic descriptor types. MBS defines the length in cells of a traffic burst relative to the peak cell rate (PCR), which it cannot exceed, and the sustainable cell rate (SCR), which it can exceed but only for the time period defined by BT.

maximum transmission unit (MTU)

1 The size (in bytes) of the largest datagram that a router or interface can

transmit.

2 The size of the largest frame that a link can transmit.

MBR

See multicast border router (MBR) (page 83).

MBS

See maximum burst size (MBS) (page 79).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

MCDN

MCR

MCS

MDCR

MDP

MDR

- 80 -

List of terms

See Meridian 1 ISDN Primary Rate Interface (MCDN) (page 81).

See minimum cell rate (MCR) (page 81).

See frame relay managed cut-through switching (MCS) (page 55).

See minimum desired cell rate (MDCR) (page 81).

See Management Data Provider (MDP) (page 78).

See management data router (MDR) (page 79).

measurement interval (T)

The time interval over which rates and burst sizes are measured. In general, its duration is proportional to the burstiness of the traffic.

media access control (MAC)

A 48-bit address unique to each local area network interface. This address is usually derived from the manufacturer’s ID number and the serial number of the interface chip set.

media gateway (MG)

A device that provides media transformation from TDM to VoIP or ATM under the control of a media gateway controller via a device control interface such as VGCP. The MG handles all the bearer traffic functionality.

media gateway controller (MGC)

A device that acts on user- or peer-device signaling to create or delete a narrowband connection on a media gateway via a device control interface such as VGCP. The MGC handles all the signaling and call control functionality.

membership scope

In PNNI networking, the level of the routing hierarchy within which advertisement of a given address is constrained.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 81 -

List of terms

Meridian 1 ISDN Primary Rate Interface (MCDN)

A common-channel signaling protocol intended for use between members of the Nortel Networks Meridian family of Private Telecommunication Network Exchanges. The signaling information is carried through time slot 16 of a

2.048 Mbit/s digital transmission system. Similarly, it is carried through time slot 23 of a 1.544 Mbit/s digital transmission system.

metric

A metric is a number that is used to represent the attractiveness (a smaller metric is more attractive) of a link or LinkGroup to a routing protocol. Some of the metrics used by Nortel Multiservice Switch are

• cost: a user-definable value

• delay: measured by the system (a lower metric represents a lower delay)

• throughput: measured by the system (higher speed links have lower

metrics)

metropolitan area network (MAN)

A network that spans a city. It is bigger than a local area network (LAN) but smaller than a wide area network (WAN).

See media gateway (MG) (page 80).

MGC

See media gateway controller (MGC) (page 80).

MIB

See management information base (MIB) (page 79).

MIB view

A specific set of components in the MIB hierarchy that is created from subsets of included and excluded subtrees.

MID

See module identifier (MID) (page 82).

minimum cell rate (MCR)

A measure of the minimum useful data rate for the given ATM UBR service category. This term is used interchangeably with MDCR.

minimum desired cell rate (MDCR)

A measure of the minimum useful data rate for the given ATM UBR service category. This term is used interchangeably with MCR.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

mixed-mode (MX)

A type of function processor that incorporates ports supporting different types of optical fiber (Meridian devices only). A mixed-mode FP contains at least one port that operates in single mode and one port that operates in multimode.

MLFR

See multilink frame relay (MLFR) (page 83).

See multimode (MM) (page 84).

MMTC

See multimedia traffic classes (MMTC) (page 84).

model

A way of describing Nortel Multiservice Switch nodes for management purposes. The two supported models are the component model and the SNMP model.

- 82 -

List of terms

module identifier (MID)

MIDs identify individual Nortel Multiservice Switch nodes or DPN-100 access modules.

MPANL

See Multiservice Passport access network link (MPANL) (page 85).

MPLS

See multiprotocol label switching (MPLS) (page 84).

MPS

See multiple priority system (MPS) (page 84).

See multi-rate (MR) (page 84).

MSA

See multiservice access function processor (MSA32 FP) (page 84).

MSA8

See Multiservice Access Function Processor (MSA8 FP), 8-port (page 85).

MSP

See Multiservice Passport access network link signaling protocol (MSP)

(page 85).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

List of terms

MTU

See maximum transmission unit (MTU) (page 79).

mu-law

Normally written as m-law. A technique for translating pulse code modulated voice into 64 kbit/s digital voice channels. m-law is used in North America, Japan, and other countries that use DS-1 function processors. See also

(page 9).

multicast border router (MBR)

A router that participates in more than one multicast domain.

multicast domain

A set of one or more contiguous links with optional routers that implement the same multicast protocol configured to operate within a common boundary.

- 83 -

A-law

multicast forwarding

A packet forwarding mode that delivers the packet to all nodes in the logical network.

multiframe

A group of frames seen as a single entity and located by a multiframe signal. Multiframing is a concept used in E1 and DS1 protocols.

multihomed address

In ATM PNNI networking, an address that is advertised by multiple PNNI nodes.

multi-hop BGP

Multi-hop border gateway protocol (BGP) refers to a BGP connection established between peers that are not directly connected and can span across multiple hops. See also

(page 51) and internal border gateway protocol (IBGP) (page 66).

multilink frame relay (MLFR)

A service for FrUni and FrNni connections. MLFR provides physical interface emulation for frame relay devices. The emulated physical interface consists of one or more DS1 links, called bundle links, that are aggregated into a single bundle that offers greatly expanded bandwidth. This service also provides a frame-based inverse multiplexing function, sometimes referred to as a inverse multiplexing for frame relay (IMUX). This definition is in accordance with the Frame Relay Forum Implementation Agreement FRF.16.

external border gateway protocol (EBGP)

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 84 -

List of terms

multimedia traffic classes (MMTC)

Subscriber options that enable you to select the traffic handling preferences from the network to meet the application requirements. MMTC handle delaysensitive multimedia traffic and minimize the delay transfer time and delay variance through the Nortel Multiservice Switch network.

multimode (MM)

Optical fiber that is capable of propagating light signals of two or more wavelengths (modes).

multiple priority system (MPS)

Nortel Multiservice Switch system proprietary priority system which defines traffic importance in terms of three emission priorities and four discard priorities.

multiport aggregate device

A multiport aggregate device breaks out the ports of the 32-port E1 AAL function processor (FP). Each multiport aggregate device provides connections for 16 E1 ports. You must use two multiport aggregate devices to break out all the ports of the FP.

multiprotocol label switching (MPLS)

MPLS is a label-swapping, networking technology that forwards packet traffic over multiple, underlying layer-2 media. This technology integrates layer-2 switching and layer-3 routing by linking the layer-2 infrastructure with layer-3 routing characteristics. Layer-3 routing occurs at the edge of the network, and layer-2 switching takes over in the MPLS network core.

multipurpose voice platform enhanced echo cancellation (MVP-E)

An MVP function processor with an on-board daughter card that provides echo cancellation capabilities according to ITU-T G.164, G.165 and G.168. The five types of Nortel Multiservice Switch MVP-E function processor are 1port DS1 MVP-E, 1-port E1 MVP-E, 4-port DS1 MVP-E, 4-port E1 MVP-E and 1-port TTC2M MVP-E.

multi-rate (MR)

The capability of a function processor (FP) to operate at multiple line rates according to specific configurations. The 4-port multi-rate POS and ATM FP (4pMRPosAtm) is an example of a multi-rate FP.

multiservice access function processor (MSA32 FP)

A function processor possessing 32 DS1 or E1 ports. The MSA FP is capable of running multiple services on Nortel Multiservice Switch nodes.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 85 -

List of terms

Multiservice Access Function Processor (MSA8 FP), 8-port

The 8-port DS1 or E1 function processor card which provides Multiservice capability on the Multiservice Switch

7400.

Multiservice Passport access network link (MPANL)

A Nortel Multiservice Switch link support service designed to communicate with Passport elements derived from ITU-T X.36 (frame relay) and signaling protocols (Q.922 and Q.933). These protocol elements enhance the treatment of voice traffic over links shared with application data and enable secure signaling as a frame relay application. MPANL includes

• components for interfacing to Passport 4400 access units using frame

relay, FrMux, and ISDN

• components for traffic shaping

• components for participating in Multiservice Switch voice and various VC

services

4400 access units. MPANL includes proprietary protocol

Multiservice Passport access network link signaling protocol (MSP)

This protocol allows end devices connected to a Passport 4400 unit to interwork with end devices of a similar type in the Nortel Multiservice Switch network. The same protocol can also allow a Passport another Passport

4400 unit in a hierarchical manner.

4400 unit to connect to

Multiservice Switch bus

Two synchronous 32-bit 25-MHz cell buses, operating in a load-sharing capacity, that can communicate with up to 16 function and control processors. Each bus operates at 800 Mbit/s for a combined speed of 1.6

Gbits/s.

Multiservice Switch cluster

A group of one or more interconnected access nodes connected to the backbone in the same RID subnet. A cluster may consist of a single node or multiple nodes. A single-node cluster is a single cluster border node providing access and not connected to any other access nodes. A multi-node cluster is a group of one or more access nodes interconnected to one or more cluster border nodes. A cluster exchanges limited routing information and no topology information with the backbone.

Multiservice Switch subnet

A number of Nortel Multiservice Switch nodes directly connected to one another.

Multiservice Switch trunk

Nortel Multiservice Switch node-to-Multiservice Switch node connection supporting core networking. Multiservice Switch trunks support the dynamic packet routing system (DPRS) and path-oriented routing system (PORS).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 86 -

List of terms

Multiservice Switch trunk over ATM

The transport mechanism used by Nortel Multiservice Switch trunks to carry cell traffic on an ATM-based interface.

Multiservice Switch trunking system

The software system that implements Nortel Multiservice Switch trunking functions, such as managing links with other Multiservice Switch nodes or DPN-100 modules.

MVP-E

See multipurpose voice platform enhanced echo cancellation (MVP-E)

(page 84).

See mixed-mode (MX) (page 82).

nailed-up endpoint (NEP)

An endpoint in a permanent connection. Nailed-up endpoints link the ATM connection to Nortel Multiservice Switch trunking over ATM.

nailed-up relay point (NRP)

An intermediate or relay point in a permanent connection. Nailed-up relay points are linked together in a Nortel Multiservice Switch node to form an

bearer service (ABS) (page 13).

NAMS ID

See 1In Nortel Multiservice Switch systems, an attribute allowing the definition

of a NAMS identifier. See NN10600-060 Nortel Multiservice Switch 7400/ 15000/20000 Component Reference for NAMS ID attribute description. (page 86).

NAMS identifier (NAMS ID)

1 In Nortel Multiservice Switch systems, an attribute allowing the definition

of a NAMS identifier. See NN10600-060 Nortel Multiservice Switch 7400/ 15000/20000 Component Reference for NAMS ID attribute description.

2 In DPN, the identifier for a subsection of a functional grouping of

administrative subsystems. See NAMS in 241-0001-002 DPN-100 List of Te r ms .

AT M

native address

An address or address prefix that matches one of the summary addresses for a given node.

NCS

See Network Clock Synchronization (NCS) System (page 87).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 87 -

List of terms

NEBS

See Network Equipment Building System (NEBS) (page 87).

NEP

See nailed-up endpoint (NEP) (page 86).

Network Clock Synchronization (NCS) System

A system used to synchronize the clocking of multiple ports and nodes in the Nortel Multiservice Switch network. NCS can be synchronized to the signal originating from a single internal source or to a source external to the network. NCS ensures the accurate transmission and reproduction of synchronous data (for example, BTDS uses NCS).

Network Engineering host

The Network Engineering host receives Nortel Multiservice Switch system statistics data in bulk data format from the Management Data Provider. The data is used by this host for planning and analysis of network operations.

Network Equipment Building System (NEBS)

The Telcordia standards for power cabling, grounding, and environmental safety, power, and operation interfaces for telecommunications equipment. The NEBS frame is used to house telecommunications equipment.

Network Equipment Building System (NEBS) 2000 frame

A Nortel Networks universal frame used to house a Nortel Multiservice Switch device. The installation consists of two half NEBS frames bolted together back to back. The NEBS frame measures 600 mm in width by 600 mm in depth by 2125

mm in height.

Network File System (NFS)

A seamless file system that can operate over a whole network. It is based on Sun’s NFS protocol and operates on IP networks using IP and UDP or TCP.

networking

Networking allows for the transfer of packets from source to destination through Nortel Multiservice Switch routing, trunking, and traffic management systems.

network interface specification A211-1 (NIS A211-1)

A North American variant of an ISDN CCS signaling protocol supported by Nortel Multiservice Switch voice networking service. See also common channel signaling.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 88 -

List of terms

network interworking function (NIWF)

The FR-ATM network interworking function (NIWF) enables frame relay CPE connectivity across frame relay networks interconnected over a backbone ATM network. The NIWF encapsulates frame relay traffic over ATM and multiplexes many frame relay DLCIs to one ATM VCC. The FR-ATM network interworking function is based on the FRF.5 standard.

See also, FR-ATM interworking service (page 56).

network management interface (NMIF)

An interface between Nortel Multiservice Switch nodes and external entities for management purposes, using a specific protocol. The supported interface and protocol types are: local, Telnet, Ssh, FMIP, and FTP (both non-secure and secure).

network management interface system (NMIS)

Manages interfaces between the Nortel Multiservice Switch software and external network management systems. Through NMIS, commands can be issued to Nortel Multiservice Switch nodes from network managers, and results returned. This allows Multiservice Switch nodes to be controlled and monitored.

network mask

A 32-bit value that masks (or causes a router to ignore) portions of a packet’s address. This technique allows the administrator to subdivide the logical network from the IP address.

network processing unit

A programmable device that specializes in the processing of data packets.

network protocol

A protocol that consists of an address plan, a frame format, and a state machine for the protocol's behavior.

network service access point address

An address used in ATM-based services (for example, PORS and Circuit Emulation) to identify objects in a network. It is defined in RFC 1629 and in ATM USER-Network Interface (UNI) Signalling Specification (Version 4.0), released by the ATM Forum Technical Committee, July 1996.

network time protocol (NTP)

A public network time synchronization protocol that Nortel Multiservice Switch XNTP software can use to synchronize the time between different nodes in a network. RFC 1305, Network Time Protocol (Version 3), defines the standards for this protocol.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 89 -

List of terms

Network Time Synchronization (NTS) System

A system that maintains time-of-day synchronization for all devices in the Nortel Multiservice Switch network. NTS resides in the control processor software and synchronizes the local real-time clock interface module from an IP-reachable network management system time server connection. NTS also accepts local operator commands for setting the local time.

When NTS for Nortel Multiservice Switch, NTS for Nortel Multiservice Data Manager, and NTS for DPN-100 are used together, they provide one network time-of-day reference used by all DPN-100 modules, Multiservice Data Manager workstations, and Multiservice Switch nodes in the network.

network-to-network interface (NNI)

Frame relay service can be provided through a standard interface between two frame relay networks of different manufacture. The interface is called the network-to-network interface. For more information, see NN10600-900 Nortel

Multiservice Switch 7400/15000/20000 Frame Relay Technology Fundamentals.

NFAS

NFS

NIWF

NMIF

NMIS

NNI

NNID

NPU

See non-facility associated signaling (NFAS) (page 90).

See Network File System (NFS) (page 87).

See network interworking function (NIWF) (page 88).

See network management interface (NMIF) (page 88).

See network management interface system (NMIS) (page 88).

See network-to-network interface (NNI) (page 89).

See non-adjacent network identifier (NNID) (page 90).

See “network processing unit” (page 88).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

nodal state parameter

Information that captures an aspect or property of a node.

node ID

A unique number used to identify a specific Nortel Multiservice Switch node within a network. See NN10600-060 Nortel Multiservice Switch 7400/15000/ 20000 Component Reference for more information.

Node Management System

A system that supports maintenance, monitoring, and testing of Nortel Multiservice Switch hardware and software, as well as the facilities for connecting Multiservice Switch devices to other network elements.

node name

A unique name used to identify a Nortel Multiservice Switch node within a network. The name is an ASCII string that contains a maximum of 12 characters. See NN10600-060 Nortel Multiservice Switch 7400/15000/20000 Component Reference for more information.

- 90 -

List of terms

node NSAP address

The attributes nodePrefix and alternatePorsPrefix, provisioned under the Mod component, that are broadcast and stored in the Base Routing Topology Database. They are also referred to as node addresses. See NN10600-435

Nortel Multiservice Switch 7400/15000/20000 Operations: Path-Oriented Routing System for more information.

non-adjacent network identifier (NNID)

A numeric identifier assigned to a network that is indirectly connected to this network through one or more adjacent networks.

non-associated signaling

Uses separate logical paths and multiple nodes as signaling links.

non-branching node

A node that cannot currently support additional branching points for point-tomultipoint calls.

non-elastic connection

An ATM connection type that cannot respond to changes in bandwidth over an ATM link by decreasing or increasing its data rate. If there is insufficient bandwidth, the connection is released. Compare with

(page 47).

elastic connection

non-facility associated signaling (NFAS)

A type of signaling used by PBXs whereby a single D-channel spans multiple DS1 or E1 links.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 91 -

List of terms

non-real time variable bit rate (NRT-VBR)

A QOS class that defines the throughput connection history as bursty with an expected low cell loss ratio (CLR) for transmitted cells. NRT-VBR supports statistical multiplexing for connections, with no associated delay bounds. NRTVBR is designed to support non-real time applications.

non-operational card

A processor card that cannot provide service. The card can be absent, unprovisioned, locked, or has not yet finished loading its software.

non-switched voice

1 A Nortel Multiservice Switch 7400 node feature in which narrowband

traffic between TDM nodes is transported transparently over an ATM network.

2 See also switched voice (page 131).

Nortel Multiservice Data Manager

In general, a system that helps to control, provision, and monitor the Nortel Multiservice Switch network. In Nortel Networks documents, this term most often refers to Multiservice Data Manager, Nortel Networks’s proprietary network management system.

Nortel Multiservice Data Manager software

A network management software system for controlling, provisioning, and monitoring DPN and Nortel Multiservice Switch networks. It consists of a set of applications supported by a common user interface running on a UNIX operating system. Multiservice Data Manager uses a commercially available hardware platform, such as a Sun SPARC station.

NPI

See numbering-plan indicator (NPI) (page 92).

NRP

See nailed-up relay point (NRP) (page 86).

nrtVBR

See non-real time variable bit rate (NRT-VBR) (page 91).

NSAP address

See network service access point address (page 88).

NscNull

A Network Systems Corporation (NSC) proprietary encapsulation method that supports IP traffic over permanent virtual circuits (PVC).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

List of terms

NTP

See network time protocol (NTP) (page 88).

NTS

See Network Time Synchronization (NTS) System (page 89).

numbering-plan indicator (NPI)

The part of a given data network address that defines the numbering plan to which it belongs. Examples of numbering plans defined by ITU-T are X.121 and E.164.

OAM

See operations, administration, and maintenance (OAM) (page 93).

OC-3

Optical carrier level 3. In SONET networks, OC-3 is the optical form of the first SONET multiplexing level when it is transmitted through an optical fiber. The

155.52 Mbit/s OC-3 signal is made up of three multiplexed OC-1 basic channels.

- 92 -

OC-12

An optical carrier signal in the SONET optical format that is 12 times the OC1 rate.

OC-48

A high-speed optical carrier signal in the SONET optical format providing a line rate of 2.488 Gbits/s, ATM services, and traffic management.

OC-N

Optical Carrier level N. The optical signal that results from an optical conversion of an STS-N signal.

off-network call

A call destined to another network. An off-network call crosses one or more gateways.

on-network call

A call that is routed internally through the SCR and DCR systems to a destination within the network.

open shortest path first (OSPF)

An IP routing model defined in RFC 1583, whereby the shortest route to a destination is calculated from a database of link states.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 93 -

List of terms

Open Systems Interconnection (OSI)

A suite of communication protocols, network architectures, and network management standards produced by the International Standards Organization (ISO). The aim of OSI is to provide information transfer in a nonproprietary environment. The protocols are open in nature, that is, defined in an agreed forum by vendors and government committees.

operations, administration, and maintenance (OAM)

A segment boundary associated with an ATM interface or a specific connection passing through that interface.

If the interface is on an OAM segment boundary, all connections passing through the interface terminate OAM segment loopback cells. If the interface is not on a segment boundary, OAM segment loopback cells pass through transparently. The setting for the segment boundary at the interface level can be overridden at the connection level for nailed-up relay points in an ATM bearer service connection.

operational attribute

Provides information or data used for monitoring the operation of Nortel Multiservice Switch nodes and services. The values of operational attributes are not retained across system restarts. These values cannot be provisioned, but some of them can be set. Operational attributes include information such as component OSI management state and statistical data.

operational card

A processor card that is capable of providing service. The card can operate as either an active instance or a standby instance.

operational component

A component that is created automatically by Nortel Multiservice Switch systems to represent some modeled entity that is dynamic in nature. An operational component can contain only operational attributes and subcomponents. It can also be created using operator commands. Operational information is not retained in the event of a power outage.

optimization

A PORS feature that allows operational paths to be evaluated based on their current path characteristics against new paths that are determined by Route Selector. If the new path can minimize the original paths provisioned metric (cost or delay), then the current path will be moved to the more optimal path.

optimization metric

An optimization metric refers to the route computation criteria that is minimized when finding the best path for a call.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

option

An option modifies the behavior or provides more information about a verb being applied to a component. For example, the display -p option shows provisioned data and the display -o option shows operational data.

option type

The data type of an option.

option value

The entered value for an option, as permitted by its type.

OSI

See Open Systems Interconnection (OSI) (page 93).

OSI state

Nortel Multiservice Switch systems define component states according to the OSI standards. A component has three high-level state variables: operational, usage, and administrative. These states are the primary factors affecting the management state of the component. For more information, see NN10600-520 Nortel Multiservice Switch 7400/15000/20000 Fault and

Performance Management: Troubleshooting

- 94 -

List of terms

OSI status

In addition to the three state attributes, six status attributes exist within OSI. The primary function of these attributes is to provide additional information about a component’s operability and usage. The attributes are: alarm status, procedural status, availability status, control status, standby status, and unknown status. For more information, see NN10600-520 Nortel Multiservice

Switch 7400/15000/20000 Fault and Performance Management: Troubleshooting.

OSPF

See open shortest path first (OSPF) (page 92).

outside link

A link to a lowest-level outside node. In contrast to an inside link (that is, a horizontal link) or an uplink, an outside link does not form part of the PNNI topology. As a result, nodes do not include outside links in route selection.

overflow routing

Overflow routing is the process by which Nortel Multiservice Switch networks switch traffic from a chosen link to an alternate link, when the chosen link becomes congested. Normal reliability traffic will overflow only to links in the same link group. High reliability traffic can also overflow onto links in a different link group, under certain conditions.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

P-node

P’

PABX

packet

- 95 -

List of terms

See “provider nodes (P)” (page 107).

Provider node within the Carrier’s Carrier domain.

See path administrator (PA) (page 97).

See private branch exchange (PBX) (page 105).

Packet is a term that can be used interchangeably with frame to mean a variable-length data unit.

The term frame means a generic variable-length data unit. Packets are generally used in layer 3 and frames in layer 2.

packet delay variation (PDV)

The measurable variation in the interval between AAL2 packets arriving at a network element. The accumulation of this variation results in packet clumping.

packet delay variation tolerance (PDVT)

PDVT defines the tolerance to AAL2 packet clumping that results from the accumulating amount of packet delay variation or “jitter” in the network or customer premises equipment (CPE).

packet forwarding

A term used to describe the process of moving packets from node to node on the network. See also

unicast forwarding (page 138) and multicast forwarding

(page 83).

packet forwarding table

Information relating to network topology that is used to route packets to paths that are appropriate to their requirements. For example, packet headers specify the destination and the priority of the packet. This is checked against the packet forwarding tables, which contain information about the network. The packet is then sent along the path that best fits its requirements.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

Packet over SONET

When POS is supported, the generic queue manager (GQM) function processor (FP) cards of a Nortel Multiservice Switch Switch

15000, or Multiservice Switch 20000 nodes transmit or receive packets over SONET (POS), or over SDH. POS handles whatever the packetbased data is because it is a layer 3 protocol over a layer 1 transmission with no layer 2.

packet voice gateway (PVG)

A gateway between an ATM network and service provider networks that allows voice and voice band data traffic to be delivered over an ATM broadband network instead of the narrowband nodes of the PSTN.

The term “PVG” is synonymous with the term “media gateway”. Refer to media

gateway (MG) (page 80) for more information.

- 96 -

List of terms

7400, Multiservice

panic

An abnormal halt to operations caused by an internal error. When an internal error occurs and the router is unable to recover gracefully, the router generates a text string, saves logout areas, and halts operations. A panic can lead to a restart if the nucleus is configured to restart on error.

parent node

The logical group node that represents the containing peer group of a specific node at the next higher level of the hierarchy.

parent peer group

The parent peer group of a peer group contains the logical group node that represents that peer group.

partial packet discard (PPD)

A Nortel Multiservice Switch ATM traffic management strategy through which cells are discarded if they belong to a frame that has had one or more cells previously discarded. This strategy ensures that cells that will eventually be discarded at the endpoints are not transmitted across the network, thereby increasing network good-put.

party

Is sometimes used interchangeably with leaf. However, a party should more accurately be considered as a component of a PMP call with its primary attribute being the destination that it defines. For example, in a PMP SPVC context, a provisioned party on the SPVC will result in a leaf when that portion of the PMP connection terminates. Branches for the PMP call in transit nodes can be servicing single or multiple parties, each of which will terminate at a leaf.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

List of terms

Passport 4400

A low-cost Nortel Multiservice Switch network access unit capable of multiplexing voice, fax, video, and LAN traffic onto a frame relay interface.

Passport Carrier Release (PCR)

The Passport Carrier Release (PCR) is the software load that runs on these members of the Nortel Multiservice Switch family:

• Multiservice Switch 7400 series

• Multiservice Switch 15000

• Multiservice Switch 15000 VSS

• Multiservice Switch 20000

One load supports all of these nodes. Each PCR is given an incremental version number, 4.1 for example. The software version directly supports specific hardware and software functionality and services that are added or changed for a release.

- 97 -

Passport queue controller (PQC)

A hardware chip on some Nortel Multiservice Switch ATM function processors that performs base layer functions, such as ATM cell forwarding and frame forwarding for frame relay and IP traffic.

Passport to Passport interface (PPI)

A proprietary ATM interface between Nortel Multiservice Switch nodes. The PPI is the Multiservice Switch system’s interim NNI (network-to-network interface) product while NNI standards develop.

patch

A patch is a temporary enhancement or correction to the functionality of an application version. Patches allow for a number of small changes to be made to an application until the next version of the application is available. In general, a new application version will incorporate all the changes in functionality made in the preceding patches.

path

The instance of a route for a logical connection in the network that has a flow in each direction. It is the sequence of Nortel Multiservice Switch trunks that is used to form the connection.

path administrator (PA)

A subcomponent of Nortel Multiservice Switch Tr u n k component, that is used to describe bandwidth-sharing characteristics and path activities.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

path bumping

Path bumping is the forced rerouting of an existing path by a new higher priority path of another logical connection. Bumping happens when there is not enough bandwidth in the selected Nortel Multiservice Switch trunk to establish a new path. The rerouting can in turn cause bumping of other paths. A bumped path can be rerouted on another Multiservice Switch trunk if the route selection criteria of the path are satisfied.

path endpoint

Defines each end of a path through a Nortel Multiservice Switch network.

path optimization

A process of finding and moving active connections to more optimal routes to provide better utilization of network resources and traffic resources. In path optimization, the incumbent connection segment is released after the establishment of an alternate connection segment. Path optimization is also known as soft rerouting and make-before-break rerouting.

- 98 -

List of terms

path-oriented routing system (PORS)

Nortel Multiservice Switch routing system in which the path is determined when the connection is set up and is fixed for the duration of the connection. In the event of

Multiservice Switch trunk failure, the path can be rerouted. The path then remains fixed in its new configuration. An advantage of pathoriented techniques is that the delay variance between two endpoints can be minimized by specifying the path in advance. This characteristic is important for some traffic types, for example, a video signal carried over a transparent data service (TDS).

path scope

The highest level reached in the private network-to-network interface (PNNI) hierarchy when calculating the path.

path trace

A control plane mechanism that determines the physical nodes and physical links traversed by new connections in the process of being established.

payload

A term used when discussing layered protocols for data communications. The payload for one layer is the information delivered to it by the layer above it. The header information added by that higher layer is considered to be part of the payload.

payload type identifier (PTI)

A field in the ATM cell header that identifies the type of data carried by the cell.

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 99 -

List of terms

P-SPVC

See permanent switched permanent virtual circuit (P-SPVC) (page 100).

P-switched permanent virtual circuit (P-SPVC)

See permanent switched permanent virtual circuit (P-SPVC) (page 100).

PBX

See private branch exchange (PBX) (page 105).

PCM

See pulse code modulation (PCM) (page 109).

PCR

See peak cell rate (PCR) (page 100) or Passport Carrier Release (PCR)

(page 97).

PCS

PDU

PDV

PDVT

PDH

PDR

See processor control system (PCS) (page 106).

See protocol data unit (PDU) (page 107).

See packet delay variation (PDV) (page 95).

See packet delay variation tolerance (PDVT) (page 95).

Plesiochronous Digital Hierarchy. An electrical transmission format. The precursor to SDH.

See protected default route (PDR) (page 106)

See “provider edge router (PE)” (page 107).

PE’

See “Carrier’s Carrier provider edge router (PE’)” (page 24).

PEC

See product engineering code (PEC) (page 106).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

- 100 -

List of terms

peak cell rate (PCR)

The maximum transfer rate into a network, defined as upper bound on the inverse of the time interval between two consecutive ATM cell emissions.

peer database exchange protocol

A protocol between two neighboring ATM nodes to synchronize their topology databases over an RCC channel.

peer group

A set of logical nodes that the network engineer groups together for the purposes of creating a routing hierarchy. All members of the group exchange PTSEs.

peer group identifier

A string of bits that unambiguously identifies a peer group.

peer group leader (PGL)

A node in a peer group that performs the extra work of collecting, aggregating, and building data that represents the entire peer group as a single node. The PGL makes this representation available to the network through the parent node.

peer group leader election (PGLE)

The peer group leader election is the process by which a single node in a peer group is elected to be the peer group leader.

performance measurements

Real-time statistics that are collected by the data collection system (DCS) from various applications. These real-time statistics are used for day-to-day troubleshooting activities.

permanent logical connection (PLC)

A connection that is an association between two points in the network for the purpose of exchanging data. The connection is called permanent because it is set up by PORS when the service is provisioned.

permanent switched permanent virtual circuit (P-SPVC)

1 In frame relay networking, a configured connection between two SPVC

endpoints in different frame relay networks. The P-SPVC uses a switched connection (S-SPVC) across frame relay network-to-network interfaces (NNIs) to establish end-to-end connectivity.

2 See also switched permanent virtual circuit (SPVC) (page 129).

Nortel Multiservice Switch 7400/15000/20000

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Terminology

Panasonic 15000 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents

What’s new

Secure shell (Ssh) on Nortel Multiservice Switch 15000 and 20000

Load Re-balancing on Parallel Links

List of terms