Avaya Differentiated User Manual

BayRS Version 14.00 Part No. 308620-14.00 Rev 00

September 1999 4401 Great America Parkway

Santa Clara, CA 95054

Configuring Differentiated Services

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iii

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Contents

Preface

Before You Begin .............................................................................................................xiii

Text Conventions .............................................................................................................xiv

Acronyms ........................... .......................... .......................... ......................... .................xvi

Hard-Copy Technical Manuals .................................. ...... ....... ...... ...... ....... .......................xvi

How to Get Help .............................................................................................................xvii

Chapter 1 Differentiated Services Overview

Implementing Differentiated Services .............................................................................1-1

Components of a Differentiated Services Network .........................................................1-2

Communicating with the Bandwidth Broker ....................................................................1-4

Marking Packets for Specific Services .....................................................................1-6

URL Filters .................. ....... ...... ....... ...... ............................................. ....... ...... ................1-8

Chapter 2 Starting Differentiated Servic es

Planning for a Differentiated Services Network ..............................................................2-1

Starting the Site Manager Configuration Tool .................................................................2-2

Preparing a Configuration File ........................................................................................2-2

Enabling Differentiated Services ....................................................................................2-3

Choosing A Filter Mechanism .........................................................................................2-3

Enabling COPS ........................................................................................................2-4

Enabling Static Filters ..............................................................................................2-5

Creating a Filter Template ..................................................................................2-5

Applying the Template to a Filter .......................................................................2-7

Configuring Filters for HTTP Packets ................................................................2-7

What To Do Next .............................................................................................................2-8

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Chapter 3 Customizing Differentiat ed Services

Adding a Differentiated Services Interface .....................................................................3-2

Modifying a Differentiated Services Interface .................................................................3-3

Disabling and Reenabling Differentiated Services Interfaces .........................................3-4

Disabling and Reenabling a Single Interface .............................. ....... ...... ....... ...... ...3- 4

Disabling and Reenabling All Interfaces ...................................................................3-4

Deleting Differentiated Services Interfaces .....................................................................3-5

Deleting a Single Interface .......................................................................................3-5

Deleting All Interfaces ..............................................................................................3-6

Adding COPS Servers ....................................................................................................3-6

Modifying COPS Global Parameters ..............................................................................3-7

Modifying the COPS Server Record ...............................................................................3-8

Prioritizing COPS Servers ........................................................................................3-8

Modifying the COPS Connection .............................................................................3-8

Maintaining the TCP Connection to the Server ........................................................3-9

Changing the Remote TCP Port ............................................................................3-10

Disabling and Reenabling a COPS Server ........ ....... ...... ............................................. .3-11

Deleting a COPS Server ...............................................................................................3-11

Disabling and Reenabling COPS on the Router ...........................................................3-12

Deleting COPS from the Router ...................................................................................3-12

Modifying Traffic Filters .................................................................................................3-13

DS Field and DS Police Traffic Filters ....................................................................3-13

URL Filters .................. ...... ....... ...... ....... ...... ....... ...... ....... ...... .................................3-15

Appendix A Site Manager Parameters

Interface List Parameters ............................................................................................... A-2

Interface Record Parameter ........................................................................................... A-5

Differentiated Services Global Parameter ..................................................................... A-6

COPS Global Parameters .............................................................................................. A-7

COPS Server List Parameters ....................................................................................... A-9

COPS Server Record Parameters ............................................................................... A-15

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Static Traffic Filter Parameters ..................................................................................... A-16

DS Field ................................... ............................................. ...... ....... ................... A-18

DS Police Parameters .................... ....... ...... ....... ...... ....... ...... ................................ A-19

HTTP Filter Parameter .......................................................................................... A-23

Appendix B Configuration Examples

A Differentiated Services Network Using Dynamic Filters ............................................. B-1

Configuring the Router ............................................................................................ B-4

Configure a Differentiated Services Interface ................................................... B-4

Configure COPS ............................................................................................... B-5

A Differentiated Services Network Using Static Traffic Filters ....................................... B-6

Configuring the Router ............................................................................................ B-7

Configure a Differentiated Services Interface ................................................... B-7

Configure a Static Filter .................................................................................... B-8

Index

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Figures

Figure 1-1. Differentiated Services Network ...............................................................1-4

Figure 1-2. Architecture of the Bandwidth Broker ......................................................1-5

Figure 1-3. Nortel Networks Differentiated Services Architecture ..............................1-7

Figure A-1. DiffServ Interface List Window ................................................................ A-2

Figure A-2. DiffServ Interface Record Window .......................................................... A-5

Figure A-3. Edit DiffServ Global Parameters Window ............................................... A-6

Figure A-4. Edit COPS Global Parameters Window .................................................. A-7

Figure A-5. COPS Server List Window ...................................................................... A-9

Figure A-6. COPS Server Record Window .............................................................. A-15

Figure A-7. DiffServ Static Filters Window .............................................................. A-16

Figure A-8. Create DiffServ Template Window ........................................................ A-17

Figure A-9. DS Field Window .................................................................................. A-18

Figure A-10. DS Police Window ................................................................................. A-19

Figure A-11. Add URL Window .................................................................................. A-23

Figure B-1. Differentiated Services Network .............................................................. B-2

Figure B-2. Differentiated Services Network Using Static Filters ............................... B-6

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Tables

Table B-1. Filters on the BLN Router ....................................................................... B-3

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This guide describes differentiated services and what you do to start and customize these services on a Nortel Networks router.

Before You Begin

Before using this guide, you must complete the following procedures. For a new router:

• Install the router (see the installation guide that came with your router).

• Connect the router to the network and create a pilot configuration file (see

Quick-Starti ng Router s , Conf igur ing BaySt ac k Remote Acc ess , or Connecting ASN Routers to a Network).

Preface

Make sure that you are runni ng the lates t versio n of Nortel Netw orks BayRS Site Manager software. For information about upgrading BayRS and Site Manager, see the upgrading guide for your version of BayRS.

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™

and

xiii

Configuring Differentiated Services

Text Conventions

This guide uses the following text conventions:

angle brackets (< >) Indicate that you choose the text to enter based on the

description inside the brackets. Do not type the brackets when entering the command.

Example: If the command syntax is:

ping

ip_address

ping 192.32.10.12

>, you enter:

bold text

Indicates command names and options and text that you need to enter.

Example: Enter

show ip {alerts | routes

Example: Use the

dinfo

command.

braces ({}) Indicate required elements in syntax descriptions

where there is more than one option. You must choose only one of the options. Do not type the braces when entering the command.

Example: If the command syntax is:

show ip {alerts | routes show ip alerts or show ip routes

}

, you must enter either:

, but not both.

brackets ([ ]) Indicate optional elements in syntax descriptions. Do

not type the brackets when entering the command. Example: If the command syntax is:

show ip interfaces [-alerts show ip interfaces

]

, you can enter either:

show ip interfaces -alerts

ellipsis points (. . . ) Indicate that you repeat the last element of the

command as needed.

xiv

Example: If the command syntax is:

ethernet/2/1 ethernet/2/1

parameter> <value

and as many parameter-value pairs as

needed.

. . .

, you enter

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Preface

italic text Indicates file and directory names, new terms, book

titles, and variables in command syntax descriptions. Where a variable is two or mor e words, the words are connected by an underscore.

Example: If the command syntax is:

show at <

valid_route

is one variable and you substitute one value

for it.

screen text Indicates system output, for example, prompts and

system messages. Example:

Set Trap Monitor Filters

separator ( > ) Shows menu paths.

Example: Protocols > I P ide nti fies the I P opt ion on the Protocols menu.

vertical line (

) Separates choices for command keywords and

arguments. Enter only one of the choices. Do not type the vertical line when enteri ng the command.

Example: If the command syntax is:

show ip {alerts | routes}, you enter either: show ip alerts or show ip routes, but not both.

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Configuring Differentiated Services

Acronyms

This guide uses the following acronyms:

COPS Common Open Policy Server DHCP Dynamic Host Configuration Protocol DNS domain name server GUI graphical user interface HTTP Hypertext Transfer Protocol IP Internet P rotocol ISO International Organizat ion for Stand ardization LDAP Lightweight Directory Access Protocol TCP Transmission Control Protocol URL uniform resource locator

Hard-Copy Technical Manuals

xvi

You can print selected technical manuals and release notes free, directly from the Internet. Go to support.baynetworks.com/library/tpubs/. Find the product for which you need documentation. Then locate the specific category and model or version for your hardw are or soft ware product . Usi ng Adobe Ac robat Re ader, you can open the manuals and releas e notes, search for the sections you ne ed, and print them on most standard printers. You can download Acrobat Reader free from the Adobe Systems Web site, www.adobe.com.

You can purchase selected documentation sets, CDs, and technical publications through the collateral catalog. The catalog is located on the World Wide Web at

support.baynetworks.com/catalog.html and is divided into sections arranged

alphabetically:

• The “CD ROMs” section lists available CDs.

• The “Guides/Books” section lists books on technical topics.

• The “Technical Manuals” section lists available printed documentation sets.

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How to Get Help

If you purchased a service contract for your Nortel Networks product from a distributor or authorized reseller, contact the technical support staff for that distributor or reseller for assistance.

If you purchased a Nort el Net wor ks s ervice pr ogram, c ontact one of the f ollowing Nortel Networks Technical Solutions Centers:

Technical Solutions Center Telephone Number

Billerica, MA 800-2LANWAN (800-252-6926) Santa Clara, CA 800-2LANWAN (800-252-6926) Valbonne, France 33-4-92-96-69-68 Sydney, Australia 61-2-9927-8800 Tokyo, Japan 81-3-5402-7041

Preface

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xvii

Chapter 1

Differentiated Services Overview

Differentiated services is a network architecture that lets service providers and enterprise network environments offer varied levels of servi ce for different types of data traffic. Instead of using the “best-effort” service model to ensure data delivery, differentiated services lets you designate a specific level of performance on a packet-by-packet basis. If you have applications that require high performance and reliable service, such as voice and video over IP, you can use differentiated services to give preferential treatment to this data over other traffic.

For each packet, there is a differentiated services field in the packet header that you can mark for specific service. For IP packets, this is called the DS field. The DS field has a specific value that defines how the packet is treated as it travels through the network.

Differentiated services is scalable, making it ideal for large networks. Edge devices, like Nortel Networks routers, classify much of the data, leaving less of the processing for the core of the network. In addition, the services can aggregate traffic for more efficient transmis si on.

Implementing Differentiated Services

In any differentiated services network, the edge router is responsible for filtering and marking data pa ckets for serv ice; ho wev e r , there ar e two di f ferent methods for configuring filters on the edge router.

You can install filters using one of two methods:

• Dynamically install them by a server called the bandwidth broker, which communicates with th e router u sing the Common Open Polic y Serv er (COPS) protocol. Trigger and flow filters are then automatically installed on the router.

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Configuring Differentiated Services

• Manually configure them on the edge router. You can create filters that instruct the router to mark specific packets for

special service throughout the network. If you manually configure filters, there is no need for a bandwidth broker or policy server.

Implementing a differentiated depends on your specific network requirements. If you implement differentiated services with a bandwidth broker, you have more flexibility and control over your network, but you have the cost and effort of maintaining a serv er. Conversely, if you manually configuring f i lter s, this requir es a lot of work because you must configure each router separately, but you do not have the added cost of maintaining a server.

Components of a Differentiated Services Network

The following devices comprise a differentiated services network:

•Host Resides at the sending and receiving point in the network. The host is the

device that requests service from the network.

1-2

• Bandwidth Broker The bandwidth broker typically resides in the ISP or enterprise network. Its

primary function is to act as a resource manager, keeping records of all the reserved data flows and filters and managing bandwidth allocation.

The bandwidth broker installs trigger and flow filters on the edge router. These filte rs te ll t he r outer ho w t o proc es s inc oming pa cke ts. The tri gger f ilt er detects the beginning of a traffic flow and notifies the bandwidth broker. The flow filter identi fies packet s t hat belong to a spec ific data fl ow and designates how packets that match the filter should be marked. The edge device and the bandwidth broker communicate using the COPS protocol.

The bandwidth broker may also be called the COPS server because COPS is the protocol used for communication between the broker and the edge router.

Not all differentiated services networks have a bandwidth broker. If no bandwidth broker exists, you must configure filters on the edge device.

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Differentiated Services Overview

• Policy server The policy server resides inside the ISP or enterprise network. It provides

policy admission control, which administrates network services and user authentication functions. The policy server monitors which data flows are assigned to a user and whether an application should have network access. In addition, the policy server polices data flows so it can limit the amount of high-priority traffic in the network. This prevents network resources from becoming overburdened.

In some networks, the bandwidth broker is the same device as the policy server; however, they can be different devices.

Not all differentiated services networks use a policy server.

• Edge router The edge router resides at the edge of the network. Its function is to classify

data flows and mark them by setting the DS field in the IP header. The DS field designates a specific type of service to each packet and instructs the network how to process the packet.

• Core net work device

•Server Manager

Figure 1-1

and a bandwidth broker. If you manually configure filters, the bandwidth broker and server manager would not be included.

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The core network device, which is typically a high-performance router, resides in the ISP or enterprise network. It routes data along the appropriate path through the network. This router cannot classify packets itself.

The server manager, which resides outside the network, sets up video conferences. The server manager s omet imes ac ts as the intermediar y bet ween the host and the bandwidth broker, passing on the host’s requests to the bandwidth broker. The server manager is not a requi red par t of a d if ferent iated services network.

shows a differentiated services network tha t i ncl udes a server manager

1-3

Configuring Differentiated Services

Server manager

ISP or enterprise network

Bandwidth broker/

policy server

Host

BLN

Highperformance router

Figure 1-1. Differentiated Services Network

Communicating with the Bandwidth Broker

If your differentiated services network uses a bandwidth broker, the router uses the COPS protocol to communicate with t he bandwidth broker. COPS enables the exchange of policy information between the bandwidth broker and its clients.

ASN

Host

DFS0001A

1-4

The router is the COPS client. The COPS client uses the Transmission Control Protocol (TCP) to communicate with the bandwidth broker. The COPS client can connect to only one server at a time, choosing the server from list of servers that you define.

When the router requests a f ilt er from the band width brok er , the bandwidth brok er responds with its own request to perform one or more of the following actions:

• Install a new filter.

• Update an existing filter.

• Disable or enable an existing filter.

• Delete an existing filter.

For each request, the differentiated services application on the router takes the necessary action and then sends an acknowledgment back to the bandwidth broker. Note that the bandwidth broker can also send unsolicited requests.

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Differentiated Services Overview

If an interface on the router becomes inactive or terminates, the differentiated services application deletes all filters from that interface. After the interface recover s, the r outer nee ds to r equest t he f ilter s from the bandwi dth brok er a gain. If the connection to the bandwidth broker is temporarily lost, the COPS client software atte mpts to recon nect to the s erv er. In this case, the router does not delet e the filters.

The bandwidth brok er a ssigns an I D t o ea ch f i lter b efore inst alli ng it on the rout er. The bandwidth broker can then change an installed filter based on that ID. If the bandwidth broker requests an update or removal of a nonexistent filter, the router ignores the request and sends an error message to the bandwidth broker. You can view the filters installed by the bandwidth broker using the router’s traffic filters feature, but you cannot modify them.

Figure 1-2

Policy server/COPS server GUI

shows the Nortel Networks bandwidth broker architecture.

Application server

Server manager

LDAP

LDAP server with policy database

Bandwidth broker PC using

TCP connection

to the router

LDAP

Policy information

is placed in

the database

Web server

Windows NT

DFS0004A

Figure 1-2. Architecture of the Bandwidth Broker

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Configuring Differentiated Services

Marking Packets for Specific Services

A packet’s assigned level of service determines whether it receives preferential treatment as it travels through the network. The DS field has a specific value that determines the service.

If the router communicates with a bandwidth broker, the process of installing filters and marking packets is as follows:

The edge router contacts the bandwidth broker with a configuration request. This happens automatically as part of the router’s normal differentiated services activity for each differentiated services interface.

The bandwidth broker responds by downloading a set of trigger and flow filters from its database to the edge router.

When a packet ar rives at a router’s differentiated services interface, the router checks its trigger filter and fl ow filt ers, i f an y are ins tall ed, to se e if t he pack e t matches either f ilte r’s criteria. If the pack et matches the t rigger f il ter’s criteria, the router sends a message to the bandwidth broker. (For the purposes of this explanation, we will assume that the packet did not match any previously installed flow filter.)

1-6

After the bandwidth broker receives a message from the router, it responds, possibly with its own request to install additional filters.

The router may or may not accept the additional filters because it may have a limit on the number of filters it can handle, or the filter is misconfigured with an action that is unknown to the router. If the bandwidth broker does install additional f ilters, the y are added t o the fil ter table of the diff erentiate d services interface.

Packets that arrive on that interface that match the flow filter criteria are marked by the differentiated services application with a DS-field pattern specified by t he f ilt er. The value in the DS f ield d etermi nes whethe r the pac ket is sent to a high-priority data queue for preferential treatment. This is how each packet gets marked or “differen tiated” for a specific type of service.

After a packet is marked, it is sent to the core network device where, depending on the marking, the packet receives preferential treatment as it is routed through the network and on to the destination host.

Figure 1-3

shows the Nortel Networks differentiated services architecture and

how the router marks a packet.

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Bandwidth broker/policy server

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COPS client communicates with the

TCP connection

bandwidth broker

Differentiated Services Overview

1 Inbound data

COPS client

Differentiated services

application

Classification, policing, and marking mechanism

1. Router receives data.

2. There is a trigger filter match and the differentiated services application is notified.

3. Router sends message to bandwidth broker, which includes the trigger filter ID and part of the original data packet.

4. Bandwidth broker associates traffic with a level of service. The dataflow passes policy admission control.

5. Bandwidth broker associates the level of service with bandwidth resources. The dataflow passes bandwidth admission control.

6. The bandwidth broker installs a flow filter on the router.

Flows with the DS field marked go to protocol prioritization

Protocol prioritization by mark in DS field

High queue

Medium queue

Low queue

Premium marked flows

Tiered marked flows

Unmarked flows

(best effort)

DFS0005A

Figure 1-3. Nortel Networks Differentiated Services Architecture

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Configuring Differentiated Services

URL Filters

The router can filter and mark Hypertext Transfer Protocol (HTTP) traffic based on uniform resource locator (URL) strings. For the router to use an URL filter, whether it is installed by the bandwidth broker or configured manually, it must contain the URL string and optionally, any of the following information:

• Source IP address

• Destination IP address

• Destination port (the default port is 80)

Although only the URL string is required, for efficient data transmission, it is useful to also include one of these other filter criteria.

After the trigger and flow filters are configured on the router, the router can mark inbound HTTP traffic for transmission through the network. If the router receives data that matches a URL filter, the router installs another f il ter, called the dynamic filter, on the next-hop interface, which is an interface on this same router. This filter is available for the duration of the HTTP session. This dynamic filter is deleted if there is no data a cti vity du ring th e time peri od specif ie d by the URL idle out timer. The original URL filter remains installed on the router.

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For more information about the URL idle out timer, see the URL Idle Out Timer parameter description on page A-4.

Note:

Even if you configure URL filters manually (static configuration), the differentiated services application uses COPS to install the dynamic filter. URL filters are the only filters that create these dynamic filters.

You must configure differentiated services on all possible next-hop interfaces on the router , or at le ast al l ne xt-h op in terf ace s where t he HTTP se rv ers mig ht res ide. Otherwise, the router will not be able to mark the return packets.

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