Avaya TCP User Manual

Configuring TCP Services

Router Software Version 10.0

Site Manager Software Version 4.0

Software Version BNX 6.0

Site Manager Software Version BNX 6.0

Part No. 112925 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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Statement of Conditions

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Note:

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4401 Great America Parkway, Santa Clara, CA 95054

8 Federal Street, Billerica, MA 01821

Bay Networks, Inc.

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.

Contents

About This Guide

Software Suites ................................................................................................................ xi

Audience ...........................................................................................................................xii

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

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

CompuServe .............................................................................................................xiii

InfoFACTS .................................................................................................................xiv

World Wide Web ........................................................................................................xiv

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

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

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

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

Chapter 1 Transmission Control Protocol Overview

Reliability ........................................................................................................................1-1

Connection Types ...........................................................................................................1-2

Connections and Connection States ..............................................................................1-3

TCP and IP Service Users .............................................................................................1-4

Telnet .............................................................................................................................. 1-5

File Transfer Protocol ......................................................................................................1-5

For More Information about TCP ....................................................................................1-8

Chapter 2 TCP Implementation Notes

Memory Considerations ..................................................................................................2-1

Chapter 3 Editing TCP, Telnet, and FTP Parameters

Conﬁguring and Customizing TCP .................................................................................3-2

Creating TCP ...........................................................................................................3-2

Editing TCP Global Parameters ...............................................................................3-3

TCP Global Parameter Descriptions ........................................................................3-4

Deleting TCP from the Router ..................................................................................3-6

Conﬁguring and Customizing the Telnet Server .............................................................3-6

Creating a Telnet Server ...........................................................................................3-6

Telnet Conﬁguration Parameter Descriptions ...........................................................3-7

Editing Telnet Server Global Parameters .................................................................3-8

Telnet Server Global Parameter Descriptions ..........................................................3-9

Deleting a Telnet Server from the Router ...............................................................3-16

Conﬁguring and Customizing the Telnet Client .............................................................3-16

Creating a Telnet Client ..........................................................................................3-16

Editing Telnet Client Global Parameters .................................................................3-16

Telnet Client Global Parameter Descriptions .........................................................3-17

Deleting a Telnet Client from the Router ................................................................3-18

Conﬁguring and Customizing the FTP Server ..............................................................3-19

Creating an FTP Server .........................................................................................3-19

Editing FTP Global Parameters .............................................................................3-19

FTP Global Parameter Descriptions ......................................................................3-20

Deleting the FTP Server from the Router ..............................................................3-23

Appendix A Site Manager Default Settings

TCP Parameters ............................................................................................................ A-1

Telnet Parameters .......................................................................................................... A-2

FTP Parameters ............................................................................................................ A-3

Index

Figures

Figure 1-1. TCP between IP and Clients ....................................................................1-4

Figure 1-2. FTP Client and Server .............................................................................1-6

Figure 3-1. Conﬁguration Manager Window ...............................................................3-3

Figure 3-2. Edit TCP Global Parameters Window ......................................................3-4

Figure 3-3. Telnet Conﬁguration Window ...................................................................3-7

Figure 3-4. Edit Telnet Server Global Parameters Window ........................................3-9

Figure 3-5. Edit Telnet Client Global Parameters Window ........................................3-17

Figure 3-6. Edit FTP Global Parameters Window ....................................................3-19

vii

Tables

Table 1-1. TCP Connection States ...........................................................................1-3

Table 1-2. FTP Commands Supported by the FTP Server .......................................1-7

Table A-1. TCP Conﬁguration Parameters ............................................................... A-1

Table A-2. Telnet Server Conﬁguration Parameters ................................................. A-2

Table A-3. Telnet Client Conﬁguration Parameters .................................................. A-2

Table A-4. FTP Conﬁguration Parameters ............................................................... A-3

About This Guide

If you are responsible for conﬁguring and managing Bay Networks routers or BNX platforms, read this guide to discover how to customize Bay Networks router software for Transmission Control Protocol (TCP) services.

Conﬁguring TCP Services

• An overview of TCP (see Chapter 1)

• Implementation notes that may affect how you conﬁgure TCP services (see Chapter 2)

• Instructions on editing TCP, Telnet, and FTP parameters (see Chapter 3)

Software Suites

Routing and Switching software is available in the following suites:

• The Bridge, Translation Bridge, SNMP Agent, Bay Networks HDLC, PPP, OSPF, EGP, BGP, and basic DLSw.

• The IPX, and ATM DXI, in addition to the System Suite.

• The addition to the System Suite.

• The entirety.

• The signaling, in addition to the LAN Suite.

System Suite

LAN Suite

WAN Suite

Corporate Suite

ARE ATM Suite

includes IP routing, 802.1 Transparent Bridge, Source Route

includes DECnet Phase 4, AppleTalk Phase 2, OSI, VINES,

includes ATM DXI, Frame Relay, LAPB, and X.25, in

offers

includes the System, LAN, and WAN suites in their

provides RFC 1483 and 1577 compliance, ATM UNI 3.0

• The

ARE VNR Corporate Suite

addition to the ARE ATM Suite and Corporate Suite.

provides ATM Forum LAN Emulation, in

Configuring TCP Services

• The PPP, OSPF, EGP, BGP, File-Based Performance Statistics, Frame Relay switching, and Frame Relay billing, and selected components from the Corporate, ARE A TM, and ARE VNR Corporate suites.

Availability of features and functionality described in this guide depends on the suites you are using.

Audience

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

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 IP interface.

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

Refer to

Software)

BNX Suite

Conﬁguring Routers

, depending on the type of installed software, for instructions.

includes IP Routing, SNMP Agent, Bay Networks HDLC,

Conﬁguring Customer Access and Trunks (BNX

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.

Customers also have the option of purchasing direct support from Bay Networks through a variety of service programs. The programs include priority access telephone support, on-site engineering assistance, software subscription, hardware replacement, and other programs designed to protect your investment.

xii

CompuServe

About This Guide

To purchase any of these support programs, including PhonePlus™ for 24-hour telephone technical support, call 1-800-2LANWAN. Outside the U.S. and Canada, call (408) 764-1000. You can also receive information on support programs from your local Bay Networks ﬁeld sales ofﬁce, or purchase Bay Networks support directly from your reseller. Bay Networks provides several methods of receiving support and information on a nonpriority basis through the following automated systems.

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.

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.

To open an account and receive a local dial-up number, call CompuServe at 1-800-524-3388 and ask for Representative No. 591.

• In the United Kingdom, call Freephone 0800-289378.

• In Germany, call 0130-37-32.

• In Europe (except for the United Kingdom and Germany), call (44) 272-760681.

• Outside the U.S., Canada, and Europe, call (614) 529-1349 and ask for Representative No. 591, or consult your listings for an ofﬁce near you.

Once you are online, you can reach our forum by typing the command GO BAYNETWORKS at any ! prompt.

xiii

Configuring TCP Services

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).

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

This section describes the conventions used in this guide. angle brackets (< >) Indicate that you choose the text to enter based on the

xiv

description inside the brackets. Do not type the brackets when entering the command. Example: if

ping

command syntax is

192.32.10.12

<ip_address>

, you enter

ping

About This Guide

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

➔

Example: Protocols

AppleTalk identiﬁes the

AppleTalk option in the Protocols menu.

bold text

Indicates text that you need to enter and command

dinfo

names in text. Example: Use the

command.

brackets ([ ]) Indicate optional elements. You can choose none, one,

or all of the options.

italic text

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

ellipsis points Horizontal (. . .) and vertical ellipsis points indicate

Indicates data that appears on the screen. Example:

Bay Networks Trap Monitor Filters

()

Set

omitted information.

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

Configuring TCP Services

Acronyms

ANSI American National Standards Institute ARP Address Resolution Protocol ATM Asynchronous Transfer Mode BGP Border Gateway Protocol CMIP Common Management Information Protocol DLSw data link switching EGP Exterior Gateway Protocol FDDI Fiber Distributed Data Interface FTP File Transfer Protocol IEEE Institute of Electrical and Electronic Engineers ILI intelligent link interface IP Internet Protocol MAC Media Access Control MOP Maintenance Operations Protocol OSI Open Systems Interconnection OSPF Open Shortest Path First PVCs permanent virtual circuits QENET Quad Ethernet Link Module RIP Routing Information Protocol SMDS Switched Multimegabit Data Services SNAP Subnetwork Access Protocol SNMP Simple Network Management Protocol SRM system resource modules SVCs switched virtual circuits TCP Transmission Control Protocol TCP/IP Transmission Control Protocol/Internet Protocol TFTP Trivial File Transfer Protocol

xvi

Chapter 1

Transmission Control Protocol Overview

In the 1970s, the Defense Advanced Research Projects Agency (DARPA) of the U.S. Department of Defense developed the Transmission Control Protocol (TCP) to provide communication among hosts manufactured by different vendors.

DARPA designed TCP to work within a layered hierarchy of networking protocols, using the Internet Protocol (IP) to transfer data.

This chapter introduces TCP concepts, features, and terminology and consists of the following sections:

• “Reliability”

• “Connection Types”

Reliability

• “Connections and Connection States”

• “TCP and IP Service Users”

• “Telnet”

• “File Transfer Protocol”

Since IP does not always guarantee reliable transfer of data, TCP implements several features to ensure that data arri ves at its destination uncorrupted and in the order sent. These features include

Sequence numbers.

• transmits. The receiving host uses the sequence numbers to make sure that all the data arrives in order.

TCP assigns a sequence number to each data segment it

1-1

Configuring TCP Services

•

Out-of-order caching.

sequential order and forwards them to the receiving TCP client. If TCP does not receive one or more segments and cannot complete the sequential ordering, it stores the remaining segments in cache memory for as long as the TCP connection exists. When TCP recei ves the missing segments, it takes the stored segments from cache memory, puts them into sequential order with the newly receiv ed segments, and then forw ards them to the recei ving TCP client. Out-of-order caching ensures that data arrives in the correct order while saving bandwidth and retransmission time.

As TCP receives data segments, it puts them in

Checksums.

• checksum to each segment it transmits. The receiving host recalculates the checksum, and if there is damage, discards the segment.

Flow control.

• data is sent to it. To activate ﬂow control, the receiving host advertises a

window

window is full, the sending host must stop sending data until the receiving host can open the window again. To control the rate of data transfer on your TCP connections, you can specify the maximum window size allowed for each connection.

Acknowledgment with retransmission.

• acknowledge that it has receiv ed the data. If the sending host does not receive an acknowledgment within a set timeout interval, the sending station retransmits the data. TCP determines the timeout interval by estimating the average time it takes to send a segment and receive an acknowledgment for it.

Connection T ypes

TCP allows both

TCP client

connection requests. Clients using passive opens can listen for speciﬁc connection requests or for a range of inbound requests. In an active open, the client initiates the connection.

To ensure the integrity of the data, the sending host adds a

Flow control allows the receiving host to regulate how much

that indicates how much data it can accept. When the transmit

TCP requires the receiving host to

active

and

passive

(the process or program that uses TCP) waits to accept incoming

connections (or

opens

). For passive opens, a

1-2

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