Avaya X.25 User Manual

Configuring X.25 Services

Router Software Version 10.0

Site Manager Software Version 4.0

Part No.112926 Rev. A

January 1996

4401 Great America Parkway 8 Federal Street Santa Clara, CA 95054 Billerica, MA 01821

recommendations in this document are believed to be accurate and reliable, but are presented without express or implied warranty. Users must take full responsibility for their applications of any products speciﬁed in this document. The information in this document is proprietary to Bay Networks, Inc.

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Note:

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4401 Great America Parkway, Santa Clara, CA 95054

8 Federal Street, Billerica, MA 01821

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Bay Networks Software License

9. Licensee shall not reverse assemble, reverse compile, or in any way reverse engineer the Software. [Note: For licensees in the European Community, the Softw are Directiv e dated 14 May 1991 (as may be amended from time to time) shall apply for interoperability purposes. Licensee must notify Bay Networks in writing of any such intended examination of the Software and Bay Networks may provide review and assistance.]

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(continued)

4401 Great America Parkway, Santa Clara, CA 95054

8 Federal Street, Billerica, MA 01821

Bay Networks, Inc.

About This Guide

Audience ...........................................................................................................................xi

Before You Begin ..............................................................................................................xii

Bay Networks Customer Support .....................................................................................xii

CompuServe ..............................................................................................................xii

InfoFACTS .................................................................................................................xiii

World Wide Web ........................................................................................................xiii

How to Get Help ..............................................................................................................xiv

Conventions .....................................................................................................................xiv

Ordering Bay Networks Publications ............................................................................... xv

Acronyms ......................................................................................................................... xv

Chapter 1 X.25 Overview

X.25 Interface .................................................................................................................1-1

X.25 and the OSI Model .................................................................................................1-2

Physical Layer ..........................................................................................................1-3

Data Link Layer ........................................................................................................1-3

Link Access Procedure Balanced Protocol ........................................................1-4

LAPB Implementation on Bay Networks Routers ..............................................1-4

Network Layer ..........................................................................................................1-5

X.25 Network Types ........................................................................................................1-5

How X.25 Services Work ................................................................................................1-6

Determining the X.121 Destination ..........................................................................1-7

Establishing a Virtual Circuit ....................................................................................1-8

Transmitting Data ...................................................................................................1-10

Chapter 2 Implementation Notes

X.25 Data Compression .................................................................................................2-1

Load Sharing ..................................................................................................................2-2

Clocking Sources for Routers Set Back-to-Back ............................................................2-2

Packet-level Parameters: Max Window Size and Max Packet Length ............................2-2

Flow-Control Negotiation ................................................................................................2-3

Conﬁguring LAPB for an AN or ASN ..............................................................................2-4

Conﬁguring Synchronous Lines with X.25 ......................................................................2-4

DDN Default Service Record ..........................................................................................2-5

Chapter 3 Enabling X.25 Service

Enabling X.25 on an Interface ...........................................................................................7

Selecting a Connector .......................................................................................................8

Conﬁguring X.25 Packet-level Parameters ......................................................................10

X.25 Packet-level Parameter Descriptions ................................................................11

Adding X.25 Network Service Records ...........................................................................16

X.25 Network Service Record Parameter Descriptions ............................................18

Adding X.25 Network Service Records to a Previously Conﬁgured Interface ...........20

Enabling Bridging and Routing Services on an X.25 Circuit ...........................................20

Conﬁguring IP Interfaces over X.25 Circuits ....................................................................21

Chapter 4 Editing X.25 Parameters

Editing the X.25 Global Parameter ..................................................................................32

X.25 Global Parameter Description ...........................................................................33

Editing X.25 Packet-level Parameters ..............................................................................33

X.25 Packet-level Parameter Descriptions ................................................................35

Editing X.25 Network Service Records ...........................................................................53

X.25 Network Service Record Parameter Descriptions ............................................56

Deleting X.25 Network Service Records .........................................................................65

Deleting X.25 from the Router .........................................................................................65

Appendix A X.25 Parameter Default Settings

Index

Figures

Figure 1-1. X.25 Network ...........................................................................................1-2

Figure 1-2. OSI/X.25 Correspondence .......................................................................1-3

Figure 1-3. LAPB Frame .............................................................................................1-4

Figure 1-4. Sample X.25 Conﬁguration ......................................................................1-7

Figure 1-5. Virtual Circuit Connecting Bay Networks Routers ...................................1-8

Figure 1-6. X.25 Call Request Packet Format ............................................................1-9

Figure 1-7. Setting Up an X.25 Call Connection ......................................................1-10

Figure 1-8. Routing IP Trafﬁc across the X.25 Network ............................................1-11

Figure 3-1. Add Circuit Window ..................................................................................3-2

Figure 3-2. WAN Protocols Window ...........................................................................3-3

Figure 3-3. X.25 Packet Conﬁg Window .....................................................................3-4

Figure 3-4. X.25 Service Conﬁguration Window for a PDN Network ........................3-10

Figure 3-5. X.25 Service Window .............................................................................3-11

Figure 3-6. Selecting the Protocols Add/Delete Function in the X.25 Service Conﬁguration

Window 3-16

Figure 3-7. Select Protocols Windows ......................................................................3-17

Figure 3-8. IP Conﬁguration Window ........................................................................3-18

Figure 3-9. Enter Adjacent Host Window .................................................................3-20

Figure 3-10. IP Interfaces Window .............................................................................3-21

Figure 3-11. ...............................................Adding an IP Interface to an X.25 Circuit 3-22

Figure 4-1. Conﬁguration Manager Window ...............................................................4-2

Figure 4-2. Edit X.25 Global Parameters Window ......................................................4-3

Figure 4-3. X.25 Packet Level Edit Window ................................................................4-4

Figure 4-4. X.25 Service Conﬁguration Window for a DDN Network .......................4-24

vii

Tables

Table 2-1. X.25 Packet-level Parameters ..................................................................2-3

Table 2-2. X.25 Service Record Parameters ............................................................2-3

Table 2-3. Synchronous Line Parameter Defaults for X.25 .......................................2-4

Table 4-1. Parameter Settings for Flow-Control Negotiation ...................................4-13

Table 4-2. User Facilities and Codes ......................................................................4-33

Table A-1. X.25 Global Parameter ........................................................................... A-1

Table A-2. X.25 Packet-level Parameters ................................................................. A-1

Table A-3. X.25 Network Service Record Parameters .............................................A-4

About This Guide

If you are responsible for conﬁguring and managing Bay Networks™ routers, read this guide to learn how to customize Bay Networks router software for X.25 services.

Audience

Conﬁguring X.25 Services

• An overview of Bay Networks X.25 services (Chapter 1)

• Implementation notes that may affect how you conﬁgure X.25 services (Chapter 2)

• Directions for enabling X.25 (Chapter 3)

• Descriptions of X.25 parameters and instructions for editing those parameters (Chapter 4)

• Default parameter settings (Appendix A)

Written for system and network managers, this guide describes how to conﬁgure the Bay Networks implementation of X.25 services to suit your environment.

offers

Configuring X.25 Services

Before Y ou Begin

Before using this guide, you must complete the following procedures:

• Create and save a conﬁguration ﬁle that has at least one X.25 interface.

• Retrieve the conﬁguration ﬁle in local, remote, or dynamic mode.

• Reboot the router with the conﬁguration ﬁle.

Refer to

Conﬁguring Routers

for instructions.

Bay Networks Customer Support

Bay Networks provides live telephone technical support to our distributors, resellers, and service-contracted customers from two U.S. and three international support centers. If you have purchased your Bay Networks product from a distributor or authorized reseller, contact the technical support staff of that distributor or reseller for assistance with installation, conﬁguration, troubleshooting, or integration issues.

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CompuServe

xii

Bay Networks maintains an active forum on CompuServ e. All you need to join us online is a computer, a modem, and a CompuServe account. We also recommend using the CompuServe Information Manager software, available from CompuServe.

About This Guide

The Bay Networks forum contains libraries of technical and product documents designed to help you manage and troubleshoot your Bay Networks products. Software agents and patches are available, and the message boards are monitored by technical staff and can be a source for problem solving and shared experiences.

Customers and resellers holding Bay Networks service contracts can visit the special libraries to acquire advanced levels of support documentation and software.

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InfoFACTS

InfoFACTS is the Bay Networks free 24-hour fax-on-demand service. This automated system contains libraries of technical and product documents designed to help you manage and troubleshoot your Bay Networks products. The system can return a fax copy to the caller or to a third party within minutes of being accessed.

W orld Wide Web

The World Wide Web (WWW) is a global information system for ﬁle distribution and online document viewing via the Internet. You need a direct connection to the Internet and a Web Browser (such as Mosaic or Netscape).

xiii

Configuring X.25 Services

Bay Networks maintains a WWW Home Page that you can access at http://www.baynetworks.com. One of the menu items on the Home Page is the Customer Support Web Server, which offers technical documents, software agents, and an E-mail capability for communicating with our technical support engineers.

How to Get Help

For additional information or advice, contact the Bay Networks Technical Response Center in your area:

United States 1-800-2LAN-WAN Valbonne, France (33) 92-966-968 Sydney, Australia (61) 2-903-5800 Tokyo, Japan (81) 3-328-005

Conventions

arrow character (➔) Separates menu and option names in instructions.

➔

Example: Protocols

AppleTalk identiﬁes the

AppleTalk option in the Protocols menu.

xiv

bold text

italic text

Indicates text that you need to enter and command

dinfo

names in text. Example: Use the

command.

Indicates variable values in command syntax descriptions, new terms, ﬁle and directory names, and book titles.

quotation marks (“ ”) Indicate the title of a chapter or section within a book.

screen text

Indicates data that appears on the screen. Example:

Bay Networks Trap Monitor Filters

Set

vertical line (|) Indicates that you enter only one of the parts of the

command. The vertical line separates choices. Do not type the vertical line when entering the command.

Example: If the command syntax is

show at routes show at routes

nets

, you enter either

show at nets

, but not both.

Ordering Bay Networks Publications

To purchase additional copies of this document or other Bay Networks publications, order by part number from Bay Networks Press™ at the following numbers. You may also request a free catalog of Bay Networks Press product publications.

Phone: 1-800-845-9523 FAX - U.S./Canada: 1-800-582-8000 FAX - International: 1-916-939-1010

Acronyms

BFE Blacker Front-End BOFL Breath of Life (message) CPU central processing unit CUG closed user group CUGOA closed user group with outgoing access DCE Data Circuit-Terminating Equipment DDN Defense Data Network DoD Department of Defense DTE Data T erminal Equipment HDLC High-level Data Link Control IP Internet Protocol ISO International Organization for Standardization ITU-T International Telecommunications

Union–Telecommunications sector (formerly CCITT) LAN local area network LAP Link Access Procedure LAPB Link Access Procedure Balanced MIB Management Information Base OSI Open Systems Interconnection OSPF Open Shortest Path First PAD packet assembler/disassembler PDN Public Data Network PDU protocol data unit

About This Guide

Configuring X.25 Services

PLP Packet Level Protocol PPP Point-to-Point Protocol PSN packet-switching network RFC Request for Comments RIP Routing Information Protocol RPOA recognized private operating agencies SNAP Subnetwork Access Protocol TCP/IP Transmission Control Protocol/Internet Protocol VC virtual circuit

xvi

The X.25 Protocol provides access for LAN trafﬁc to packet-switching networks (PSNs). X.25 allows many different kinds of equipment to communicate across networks at a relatively low cost.

Common carriers, mainly the telephone companies, designed X.25. An agency of the United Nations, the International Telecommunications Union– Telecommunications sector (ITU-T, formerly CCITT), administers the X.25 Protocol. X.25 is a global standard, and is the dominant communications protocol in use around the world today.

X.25 Interface

Chapter 1

X.25 Overview

X.25 deﬁnes the interaction across PSNs between Data Terminal Equipment (DTE) and Data Circuit-Terminating Equipment (DCE). DTEs include devices such as terminals, hosts, and routers; DCEs include devices such as modems, packet switches, and other ports.

igure 1-1 shows an X.25 network. A DTE (in this case, Router A) connects to a

DCE in the PSN. The PSN connects to another DCE and, ﬁnally, to another DTE (Router B).

1-1

Configuring X.25 Services

PSN

Router A (DTE)

Figure 1-1. X.25 Network

To begin communication, one DTE device (for example, a router) calls another DTE to request a data exchange session. The called DTE can accept or refuse the connection. If the called DTE accepts the connection, the two systems begin full-duplex data transfer. Either side can terminate the connection at any time. Because public data networks (PDNs), the most commonly used type of PSN, typically use error-prone analog lines, the X.25 Protocol provides extensive error checking, recovery, and packet sequencing.

A DTE can be a device that does not itself implement X.25. In this case, the DTE connects to a DCE through a packet assembler/disassembler (PAD), which is a device that translates data into packet form.

X.25 and the OSI Model

Virtual Circuit Virtual Crcuit

DCE

Router B (DTE)

1-2

The Open Systems Interconnection (OSI) Basic Reference Model combines a nonproprietary structured computer system architecture with a set of common communication protocols. It comprises seven layers. Each layer provides speciﬁc functions or services and follows the corresponding OSI communications protocols to perform those services.

The X.25 Protocol focuses on three of the seven layers in the OSI model: the physical layer, the data link layer, and the network, or packet, layer. As you read the following sections, refer to F between X.25 and the OSI model. F

igure 1-2, which illustrates the correspondence

igure 1-2 conforms to the typical rendering of

the OSI model, which depicts the physical layer at the bottom of the protocol stack, and refers to succeeding layers as representing higher-level protocols.

OSI Model X.25 Protocol

X.25 Overview

Figure 1-2. OSI/X.25 Correspondence

Physical Layer

The physical layer manages the transmission of bits across the physical connection or modem interface. Bay Networks supports all of the standard media for X.25 transmission: X.21, X.21bis/RS232C, RS449/422, and V.35.

Network Layer

Data Link Layer

Physical Layer

X.25 Packet Layer

LAPB

X.21, X.21bis/RS232C, RS449/422, and V.35

Data Link Layer

The data link layer deﬁnes the link access procedures for transferring frames of data accurately and reliably across the access lines between the DTE and the DCE.

1-3

Configuring X.25 Services

Link Access Procedure Balanced Protocol

X.25 uses the Link Access Procedure Balanced (LAPB) protocol at the data link layer to

• Initialize the link between the DTE and the local DCE device

• Frame X.25 data packets before transmitting them to the DCE LAPB is a version of High-level Data Link Control (HDLC), which is an OSI

standard. Figure 1-3 shows a LAPB frame. The LAPB information ﬁeld contains the X.25

data packet. Once an X.25 packet reaches the destination router, the LAPB protocol strips away the LAPB frame and deliv ers the pack et to the netw ork layer for further processing.

Flag Control

Address

Information

Frame Check Sequence

Flag

Figure 1-3. LAPB Frame

LAPB Implementation on Bay Networks Routers

The implementation of the LAPB protocol on the AN® and ASN® routers, and on

and LN® routers with Octal Sync, differs from that on other Bay Networks

BN routers. On the AN and ASN routers and BN and LN routers with Octal Sync, LAPB is implemented in software in routers that use the QUICC 68360 driver. On the other routers, LAPB is implemented in the hardware using the MK5025 chip.

Note:

The different LAPB implementations r esult in two different LAPB MIBs. This means that if you copy an existing conﬁguration from a Bay Networks router that uses the MK5025 chip to the AN or ASN, or the BN or LN with octal sync, the conﬁguration may not work because the location of the LAPB MIB is different.

1-4

Although detailed discussion of the LAPB MIB is beyond the scope of this guide, when you conﬁgure X.25, you automatically set up LAPB for all routers.

Network Layer

The network, or packet, layer establishes the virtual circuit and provides procedures for call establishment, data transfer, ﬂow control, error recovery, and call clearing. The router uses the network layer to determine destination X.121 addresses and to specify which user-conﬁgurable X.25 facilities the network layer supports. (See “Determining the X.121 Destination, ” later in this chapter , for more information about X.121 addresses.) The X.25 Protocol deﬁnes its respective DCE communicate and exchange data.

X.25 Overview

how

the DTE and

The X.25 network transmits data over and destination on the network. Because as many as 128 VCs can exist on the same physical link at the same time, multiple devices can share the bandwidth of the transmission line, sending data in multiple packets from the source to the destination.

X.25 Network Types

The Bay Networks router transmits data across three types of X.25 network services.

• Public Data Network (PDN)

The X.25 PDN service provides end-to-end connectivity between the router and a remote DTE that supports Internet RFC 1356 X.25 services. IP uses PDN service to transmit IP datagrams. OSI uses PDN service to send OSI protocol data units (PDUs) over the X.25 network. No other protocols use PDN services. The Bay Networks router supports Internet RFC 1356 for IP and OSI.

• Defense Data Network (DDN)

The X.25 DDN service provides end-to-end connectivity between a router and a remote DTE that supports X.25 DDN Standard Service. IP uses DDN service to transmit IP datagrams. OSI uses DDN service to send OSI protocol data units (PDUs) over the X.25 network. No other protocols use DDN services.

virtual circuits

(VCs) between each source

1-5

Configuring X.25 Services

You can implement an X.25 DDN network as a Blacker Front-End (BFE) network. BFE is an external, standalone encryption device that you connect to your router to establish X.25 DDN networks.

• Point-to-Point Service

Point-to-Point service is proprietary to Bay Networks, so Bay Networks routers must be at both ends of the connection. AppleTalk, transparent and spanning tree bridging, DECnet, IP, VINES, XNS, IPX, and OSI can use Point-to-Point X.25 service to transmit datagrams over the X.25 network.

The type of datagram trafﬁc that the router forwards depends upon the type of network layer service enabled on each of the router’s network interfaces. For example, if you conﬁgure an interface for DDN services, you cannot conﬁgure any other type of service. You can, however, conﬁgure an interface to run PDN and Point-to-Point services together.

How X.25 Services Work

End-users on a LAN use the services of the Bay Networks router to access X.25 networks. The router acts as a DTE device; it encapsulates user data in X.25 format and transmits it across the network.

1-6

To demonstrate how Bay Networks X.25 services work, the following sections explain how Router A, which is conﬁgured for X.25 PDN services, routes data from IP endstation 1.1.1.2 over the X.25 network to IP endstation 3.1.1.2. Refer to Figure 1-4 as you read the next sections.

X.25 Overview

1.1.1.1

10000 20000

Router A Router B

1.1.1.2

IP Network IP Network

Key

DCE = Data Circuit-terminating Equipment 10000, 20000 = X.121 Addresses

Figure 1-4. Sample X.25 Conﬁguration

X.25 PDN

DCE

2.1.1.22.1.1.1

3.1.1.1

3.1.1.2

Determining the X.121 Destination

Each interface connecting to the X.25 network has an X.121 address. For example, in Figure 1-4 the X.121 network addresses for Routers A and B are 10000 and 20000, respectively. Router A communicates with Router B over the X.25 network by setting up virtual circuits that connect the two X.25 interfaces.

Data transmission begins when

1. Router A receives an IP datagram from IP endstation 1.1.1.2.

2. Router A checks its IP routing table to determine the next hop on the

datagram’s path (in this example, IP address 2.1.1.2).

3. Once Router A determines that the next hop is located across the X.25

network, it checks to see which destination X.121 address maps to the next hop’s IP address via the IP adjacent host table (in this e xample, X.121 address

20000).

1-7

Configuring X.25 Services

4. To transmit the datagram across the network, the router now establishes a

virtual connection between itself and destination X.121 address 20000. Router A begins by selecting an unused virtual circuit. The router assigns the

circuit a 12-bit virtual circuit number (Figure 1-5), which it chooses from a user-speciﬁed range of virtual circuit numbers. The virtual circuit number identiﬁes the logical channel portion of the circuit that connects the router and its DCE.

10000

Virtual circuit number = 000000000001

Logical Channel

X.25 PDN

20000

Router A

Figure 1-5. Virtual Circuit Connecting Bay Networks Routers

The logical channel consists of a 4-bit logical channel group number concatenated with an 8-bit logical channel number. The logical channel number identiﬁes this circuit as the one that will carry all data transmitted between the router and the destination DTE, once the connection to the destination X.121 address is established.

Establishing a Virtual Circuit

After Router A determines the destination X.121 address, the tw o routers establish a virtual circuit as follows:

1. Router A uses the services of the packet layer protocol to generate a call

request packet that it sends to Router B Along with various optional X.25 facilities, the call request packet speciﬁes

the outgoing logical channel number, Router A’s X.121 address, and Router B’s X.121 address (Figure 1-6).

DCE

Router B

1-8

X.25 Overview

00010000 00000001

00001011

Source Destination

X.121 Length X.121 Length

Destination X.121 Address

Source X.121 Address

Facilities Length

Facilities

Data

Logical Channel Group Number Logical Channel Number

Call Request

Figure 1-6. X.25 Call Request Packet Format

2. When the local DCE receives Router A’s call request, the DCE forwards it

across the X.25 network, where it is eventually routed to Router B.

3. Router B checks the called address for a match to its conﬁgured X.121

address. It also check the calling address for a match to the remote X.121 address conﬁgured in the service record.

4. If it ﬁnds both matches, it accepts the call, and responds with a call accept

packet that establishes the virtual connection between the two routers.

Once the virtual circuit is established, the router can transmit and receive data (Figure 1-7).

1-9

Configuring X.25 Services

1. Send Request X.25 PDN

Call Request

Router A

2. Establish Connection

Call Confirm Call Accept

Router A

3. Encapsulate and Transmit Data

User Data

Router A

DCE

X.25 PDN

DCE

X.25 PDN

DCE

Incoming Call

Router B

User Data

Router B

Figure 1-7. Setting Up an X.25 Call Connection

Transmitting Data

After Router B establishes the circuit, data travels between endstations 1.1.1.2 and

3.1.1.2 as follows:

1. Router A begins processing the packets it receives from IP endstation 1.1.1.2 across the X.25 network to Router B.

2. Router B removes the X.25 packet headers and trailers and forwards only the IP data to IP endstation 3.1.1.2 (Figure 1-8).

1-10

X.25 Overview

3. IP endstation 3.1.1.2 transmits data to endstation 1.1.1.2. Note that other IP endstations (for example, 1.1.1.3) can use the virtual circuit

to transmit data in the direction of endstation 3.1.1.2 until the call is cleared. The call request and call accept packets specify the logical channel numbers

(LCNs) assigned to the virtual connections between each router and its corresponding DCE. As a result, subsequent X.25 data packets contain only the logical channel numbers, rather than the complete X.121 destination addresses.

1.1.1.1

10000 20000

Router A Router B

1.1.1.2

1.1.1.3

IP Network IP Network

Figure 1-8. Routing IP Trafﬁc across the X.25 Network

X.25 PDN

DCE

2.1.1.22.1.1.1

3.1.1.1

3.1.1.2

1-11

Chapter 2

Implementation Notes

This chapter provides information about special features of the Bay Networks X.25 implementation, including

• Data compression

• Load sharing

• Clocking sources for routers set back to back

• Max Window Size and Max Packet Length parameters

• Flow control negotiation

• Conﬁguring LAPB for an AN or ASN

• Conﬁguring synchronous lines

• DDN default service record

X.25 Data Compression

Bay Networks data compression software enables you to reduce line costs and improve response times over X.25 networks.

Our data compression eliminates redundancies in data streams. When you use compression on your network, bandwidth efﬁciency improves, enabling you to transmit more data over a given amount of network bandwidth.

To use data compression with X.25, you must set the X.25 service record parameter, Enable Compression, to Enable. See Chapter 4 for information about how to access this parameter.

2-1

Configuring X.25 Services

For a complete discussion of data compression, descriptions of compression parameters, and instructions for conﬁguring compression for an X.25 interface,

Conﬁguring Data Compression Services

see

Load Sharing

The Bay Networks implementation of X.25 on PDN networks includes load sharing across as many as four VCs, using a round-robin algorithm to distribute trafﬁc. This feature improves performance by increasing the effective window size, that is, the number of packets that a DTE can transmit before it receives an acknowledgment.

To take advantage of multiple virtual connections and load sharing across them, you must set the Max Connections network service record parameter to a value greater than one (refer to Chapter 4).

Clocking Sources for Routers Set Back-to-Back

If two Bay Networks routers are operating back-to-back without a clocking source, you must conﬁgure internal clocking on both routers. Use a crossover cable to connect the ports.

The default clocking source for X.25 is external. When you conﬁgure X.25 and LAPB on an existing network, external clocking can cause unpredictable results on any internally clocked line. Clocking sources must be the same for each device within the network.

Packet-level Parameters: Max Window Size and Max Packet Length

When you conﬁgure X.25 packet-level parameters, make certain to set the Max Window Size and Max Packet Length parameters for peer routers to the same value. If you do not, the routers cannot perform network service-level negotiations.

For example, if you set the Max Window Size for Router A to 7, set the Max Window Size for peer Router B to 7. Similarly, if you set the Max Packet Length for Router A to 512, set the Max Packet Length for peer Router B to 512.

2-2

+ 74 hidden pages

Avaya X.25 User Manual

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