3COM 3C892 User Manual

OfficeConnect®

ISDN LAN Modem

3C892

User Guide

http://www.3com.com/

Part No. 984/000023-3 Published February1999

3Com Corporation 5400 Bayfront Plaza Santa Clara, California 95052-8145

3Com Corporation reserves the right to revise this documentation and to make changes in content from time to time without obligation on the part of 3Com Corporation to provide notification of such revision or change.

3Com Corporation provides this documentation without warranty of any kind, either implied or expressed, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. 3Com may make improvements or changes in the product(s) and/or the program(s) described in this documentation at any time.

UNITED STATES GOVERNMENT LEGENDS:

If you are a United States government agency, then this documentation and the software described herein are provided to you subject to the following restricted rights:

For units of the Department of Defense:

Restricted Rights Legend:

set forth in subparagraph (c) (1) (ii) for Restricted Rights in Technical Data and Computer Software Clause at 48 C.F.R. 52.227-7013. 3Com Corporation, 5400 Bayfront Plaza, Santa Clara, California 95052-8145.

For civilian agencies:

Restricted Rights Legend:

subparagraph (a) through (d) of the Commercial Computer Software - Restricted Rights Clause at 48 C.F.R. 52.227-19 and the limitations set forth in 3Com Corporation’s standard commercial agreement for the software. Unpublished rights reserved under the copyright laws of the United States.

If there is any software on removable media described in this documentation, it is furnished under a license agreement included with the product as a separate document, or in the hard copy documentation. If you are unable to locate a copy, please contact 3Com and a copy will be provided to you.

Unless otherwise indicated, 3Com registered trademarks are registered in the United States and may or may not be registered in other countries.

3Com and OfficeConnect are registered trademarks of 3Com Corporation. 3ComFacts is a service mark of 3Com.

Stac and LZS are registered trademarks and Hi/fn is a trademark of Stac, Inc. Pentium is a registered trademark of Intel. Windows and Windows NT are registered trademarks of Microsoft. Macintosh is a registered trademark of Apple Computer Corporation. IBM is a registered trademark of International Business Machines Corporation.

Other brand and product names may be registered trademarks or trademarks of their respective holders.

3Com Corporation, 1999.

Use, duplication, or disclosure by the Government is subject to restrictions as

Use, reproduction, or disclosure is subject to restrictions set forth in

ABLE OF

BOUT THIS GUIDE

How to Use This Guide 9 Conventions 10 Year 2000 Compliance 10

NTRODUCTION

Introduction 11 Applications 11

Local Networking with Access to the Internet 11 Local Networking with Access to a Remote Office 12 Local Networking with Access to the Internet and a Remote Office 12

Features 13

Ease of Installation and Use 13 High Performance 13 Connectivity 13 Routing 13 Bandwidth Management 14 Remote Management 14 Voice Features 14 Protocols 14 ISDN Standards and Interface 15 Security 15 Upgradability 15 Diagnostics 15 Warranty 15 Internet Applications and Games 15

ONTENTS

ISDN LAN M

UNCTIONALITY DESCRIPTION

Connection Types 17

LAN Side Connection 17

Application Sharing over the LAN 18 WAN Side Connection 18 Two Separate Connections to Different Locations. 18 One High Speed Connection to a Single Location 19

Call Routing Protocol and IP Address Translation 20

ODEM

iii

Placing a Call to a Previously Defined Destination 20

Call Routing While No Other Calls Are Connected 20 Call Routing While One Call Is Already Connected 21

Understanding Multilink PPP and BACP/BAP 21

What is Multilink PPP? 21 What is BACP/BAP? 21

Multilink PPP Configuration Options 22 Understanding Dynamic Bandwidth Allocation 22 Understanding VPNs and PPTP 23

23 Setting Up the Server Side of the Tunnel 23 Setting Up the Client Side of the Tunnel 23

For Windows Dial-Up Networking Users 24

Establishing a Tunnel via the ISDN LAN Modem 24

ARDWARE DESCRIPTION AND INSTALLATION

Package Contents 25 Before You Install the ISDN LAN Modem 25 Front Panel LED Description 26

Back Panel Connector Description 27

Installing the ISDN LAN Modem 27

Before You Begin 27 Installing the ISDN Cable 28 Connecting to a 10BASE-T Ethernet Port 28 Connecting to Another Ethernet Hub 29

Before You Begin 29 Installing Analog Equipment 30 Installing the Power Cable 31

Wall Mounting the ISDN LAN Modem 31 Using Rubber Feet and Stacking Clips 32

ETTING UP

TCP/IP Setup Using Windows 98 and Windows 95 33 TCP/IP Setup Using Windows NT 4.0 36 TCP/IP Setup Using Mac OS 7.6 or later 39 TCP/IP Setup Using Windows 3.11 40

Setting Up TCP/IP Using MS TCP 40

TCP/IP

FOR WINDOWS AND MACINTOSH

ONFIGURING THE

Typical Configuration 43 Before You Begin 43

You Should Have Done This 43 You Should Have This Information 44 Determine Whether You Use Dynamic or Static IP Addresses 44 Setting Up Your Computer If You Have a Static IP Address 45

ISDN LAN M

ODEM

For Windows 98 and 95 Users 45 For Windows NT 4.0 Users 45 For Macintosh Users 46 For Windows 3.11 Users 46

Configuring the ISDN LAN Modem for the Typical Configuration 47

Configuring a Static IP Address on the ISDN LAN Modem 51

ISDN LAN Modem Main Page 52

Links from the Illustration 52 Links from the Buttons 53

DVANCED CONFIGURATION

Before you Begin 55 Setting Up Additional Service Providers 56

ISP versus Private Network 56

When to Select ISP 56 When to Select Private Network 57

Setting Up a Connection to an ISP 57

Before You Begin 57 Setting Up a Connection to the Internet 57

Setting Up a Connection to a Private Network 60

Before You Begin 60 Setting Up a Connection to a Remote LAN 60

Associating Service Providers with Workstations on the LAN 63 Editing Service Provider Profiles 64 Restricting Workstations from Accessing Service Provider(s) 65 Configuring Your LAN Parameters 65

Understanding LAN Parameters 65

Name 65 IP Address and Subnet Mask 66 Local Domain Name 66 Enable DHCP Server 66 Enable NetBIOS Filtering 66

Configuring the LAN Parameters 67 Changing Data Call Parameters 67

Understanding Data Call Parameters 68

Minimum Call Duration 68 Disconnecting an Automatic Data Call 68 Disconnecting a Manual Data Call 68 Connect/Disconnect Threshold for the Second B Channel 69

69 69

Configuring the Data Call Parameters 69 Changing Voice Call Routing 70

Understanding How Calls Are Routed 70

Changing Voice Call Routing 70 Reserving DHCP Addresses 71 Selective Password Protection 71 Changing Your Password 72

Setting Up Your ISDN Line Manually 72 Locking and Unlocking the Configuration 73

73 74

Configuring the ISDN LAN Modem from a Remote Location 74

Configuring the ISDN LAN Modem Remotely via Another LAN Modem 74 Configuring the ISDN LAN Modem Remotely via an ISDN Modem 74

UPPLEMENTARY VOICE CALL SERVICES

Supplementary Voice Services 77

Before You Begin 77

Call Waiting 78

How to Configure Call Waiting 78 How to Use Call Waiting 79

Caller ID 80

Caller ID Date and Time 80

Caller ID Blocking 80

Flexible Calling 81

Configuring FCO on the ISDN LAN Modem 81 Flexible Calling Codes 81

Call Conference (Three-Way Calling) 82

Call Transfer 82 Message Service/Voice Mail 83 Call Forwarding 83

LACING

Placing Calls 85 Placing a Call Automatically 85

Telephone Number Selection for Data Calls 85 Call Routing Among Service Providers 85

Placing a Call Manually 86

Placing a Call Manually to an Existing Service Provider 86

Placing a Call Manually to a Temporary Service Provider 86

Participating in a Temporary Call 87

Placing Multilink PPP Calls 87 Receiving Calls 87

Receiving Data Calls 87

Receiving Voice Calls 88

Distinctive Ringing 88 Disconnecting Data Calls 88

Disconnecting Data Calls Manually 88

Disconnecting Calls Automatically Using Timers 89

Minimum Call Duration 89 Idle Timeout 89

Bandwidth on Demand Parameters 89

ECEIVING AND DISCONNECTING CALLS

, R

Connect/Disconnect threshold for the second B channel 89

89 89

ROUBLESHOOTING AND MAINTENANCE

Checking the Basics 91 Monitoring LEDs 92

Monitoring the ALERT LED 92 Monitoring the ISDN LED 92 Monitoring the

B Channel LEDs 92 Monitoring the LAN Port Status LEDs 92

Troubleshooting Problems Indicated by LEDs 93 Evaluating Symptoms and Solutions 94 Finding More Information 100 Contacting Technical Support 100 Downloading Firmware to Your ISDN LAN Modem 100 Resetting the ISDN LAN Modem 100

Resetting the ISDN Modem Using a Telephone 100 Reviewing Statistics 101

Understanding System Statistics 101

Understanding ISDN Information 102

Understanding Current Call Information 102

Understanding Last Call Information 103

Understanding Service Provider Information 104

ETWORKING PRIMER

What is a network? 105

What is a LAN? 105

What is a WAN? 105

How does a LAN connect to a WAN? 106

What is a LAN modem? 106

What is ISDN? 106

How do different devices communicate with each other? 107

What is TCP/IP? 107

What is an IP Address? 108

What is a Subnet Mask? 108

Dynamic and Static IP Addresses 108

What is DHCP? 109

What is DNS? 109

What is NAT? 109

What are numbered and unnumbered links? 109

How is overall throughput determined? 109

SING THE CUSTOM WEB BROWSER

Custom Links 111 Using Favorites 112 Installing the Custom Internet Explorer Browser 112

vii

Installing Future Releases of Internet Explorer 112

ISDN LAN M

Year 2000 Compliance 116

RDERING

If You Place Your ISDN Order Through 3Com 117 If You Place Your ISDN Order Through the Telephone Company 117

Placing Your Order 118

Supplementary Voice Features Included with U, EZ-ISDN-1, V and EZ-ISDN 1A 119

119

Limitations of ISDN Ordering Codes U, EZ-ISDN 1, V and EZ-ISDN 1A 119

Simultaneous Voice and Data on the Same Telephone Number 119 Supplementary Voice Services on Telephone Number 1 Only 120 If You Must Have Simultaneous Voice and Data Capability on Both Numbers 120

For Lucent Technologies 5ESS For Siemens EWSD Switches 120 For Nortel DMS-100

What If I Already Have ISDN Service? 121

How S1 Differs from U/EZ-ISDN 1 and V/EZ-ISDN 1A 121

If You Are Currently Using Capability Package S1 and Would Like to Add Supplementary Voice Services 121

If You Are Unable to Have Supplementary Voice Services Added to S1 121

Table of ISDN Ordering Code Capabilities 122

ODEM FACTORY DEFAULTS

ODEM SPECIFICATIONS

ISDN S

ERVICE

Switches 121

Switches 120

LOSSARY

NDEX

3COM C

ORPORATION LIMITED WARRANTY

viii

BOUT

About This Guide provides an overview of this guide, describes guide conventions, and tells you where to look for specific information.

This guide describes how to install and configure the OfficeConnect ISDN LAN Modem and provides descriptions of key applications and networking concepts.

HIS

UIDE

Audience Description

How to Use This Guide

This guide is intended for end users with no presumed level of expertise.

Table 1 shows where to find specific information in this guide.

Table 1

If you are looking for... Turn to...

An overview of the ISDN LAN Modem Chapter 1 An explanation of the ISDN LAN Modem’s key functionality Chapter 2 A description of the ISDN LAN Modem’s hardware components Chapter 3 Instructions on setting up TCP/IP Chapter 4 Instructions for the typical configuring of the ISDN LAN Modem software Chapter 5 Instructions for advanced configuration of the ISDN LAN Modem software Chapter 6 Information on supplementary voice services Chapter 7 Information on placing, receiving and disconnecting calls Chapter 8 Information on troubleshooting and maintenance Chapter 9 Background information on networking Appendix A Information on using the custom browser Appendix B ISDN LAN Modem factory default settings Appendix C Technical specifications for the ISDN LAN Modem Appendix D Instructions for ordering ISDN service for the ISDN LAN Modem Appendix E Definition of terms Glossary

10 A

BOUT THIS GUIDE

Conventions

Table 2 and Table 3 list conventions that are used throughout this guide.

Table 2

Icon Notice Type Description

Table 3

Convention Description

Screen displays

Commands

The words “enter” and “type”

Keyboard key names If you must press two or more keys simultaneously, the key names are

Words in italics Italics are used to:

Notice Icons

Information note Information that describes important features or instructions

Caution Information that alerts you to potential loss of data or potential

Warning Information that alerts you to potential personal injury

damage to an application, system, or device

Text Conventions

This typeface represents information as it appears on the screen. The word “command” means that you must enter the command

exactly as shown and then press Return or Enter. Commands appear in bold. Example:

To remove the IP address, enter the following command:

SETDefault !0 -IP NETaddr = 0.0.0.0

When you see the word “enter” in this guide, you must type something, and then press Return or Enter. Do not press Return or Enter when an instruction simply says “type.”

linked with a plus sign (+). Example:

Press Ctrl+Alt+Del

■

Emphasize a point.

■

Denote a new term at the place where it is defined in the text.

■

Identify menu names, menu commands, and software button names. Examples:

From the Help menu, select Contents. Click OK.

Year 2000 Compliance

The OfficeConnect ISDN LAN Modem is Year 2000 compliant. Specifically, its system clock is capable of accepting and storing dates including and beyond the year 2000.

For information on Year 2000 compliance and 3Com products, visit the 3Com Year 2000 Web page:

http: // www.3c om. com/products/yr2000 .h tml

NTRODUCTION

This chapter provides an overview of the OfficeConnect® ISDN LAN Modem, referred to throughout this document as the ISDN LAN Modem.

Introduction

Applications

Local Networking with

Access to the Internet

The ISDN LAN Modem is an easy to install, LAN to WAN modem. For the LAN, it provides four 10BASE-T Ethernet connections— expandable to 25 connections. Refer to Figure 1 for an example showing 10 connections by adding an 8-port 10BASE-T Ethernet hub. For WAN access, it provides a Basic Rate Interface (BRI) ISDN port.

With the ISDN LAN Modem, small office and home office users can share remote access to the Internet or to a remote office while continuing to network locally.

The primary application for the ISDN LAN Modem is:

■ Local networking with shared access to the Internet and/or a remote office

LAN.

Users can share access to the Internet while continuing to network locally.

Network Utilization

3 Com

Office

Connect Hub

Internet/Intranet

online service

PWR COLLPKT COAX1234

Alert

OfficeConnect Hub 8 TPO

Port Status

5678

green = link OK, off = link fail, yellow = partition

1% 2% 3% 6% 12%25%50% 80%

Figure 1

OfficeConnect ISDN LAN Modem

PWR

ISDN

Alert

Local Networking with Access to the Internet

Coll

LAN STATUS

OfficeConnect™

ISDN LAN Modem

2 3 4

3 Com

ISDN BRI line

Public telephone

network

12 C

HAPTER

1: I

NTRODUCTION

Local Networking with

Access to a Remote

Office

Local Networking with

Access to the Internet

and a Remote Office

Users can share access to a remote office LAN while continuing to network locally.

Remote office

LAN

Figure 2

OfficeConnect ISDN LAN Modem

PWR

ISDN

Alert

LAN STATUS

Coll

3 Com

OfficeConnect™

2 3 4

ISDN LAN Modem

Public telephone

network

ISDN BRI line

Local Networking with Access to a Remote Office

Users can share access to a remote office and the Internet while continuing to network locally.

Figure 3

Internet/Intranet or

online service

OfficeConnect ISDN LAN Modem

LAN STATUS

OfficeConnect™

2 3 4

Coll

PWR

ISDN

Alert

ISDN LAN Modem

3 Com

Public telephone

network

Remote office

LAN

ISDN BRI line

Local Networking with Access to a Remote Office and the Internet

Features 13

Features

Ease of Installation and Use

■ SPID Wizard automatic configuration for telephone company switch and

service profile ID (SPID) numbers.

■ Web-based, point-and-click user interface for configuration and online help.

■ Automatic configuration verification with Internet connection through your

Internet Service Provider (ISP).

■ Firmware updates, user guides and technical notes available on the Web.

High Performance

■ Hi/fn™ LZS

Compression Control Protocol

Protocol

■ Multilink PPP (RFC 1990), which combines two PPP B channel calls to create a

compression, which conforms to these IETF RFCs:

(RFC 1962) and

PPP Stacker LZS Compression

(RFC 1974).

The PPP

virtual, single 128 Kbps network connection.

■ TollMizer, which places a single B channel or a Multilink PPP data call over a

voice connection, saving you the additional charge for a data call.

Connectivity

■ ISDN Basic Rate U interface.

■ Built in four-port 10BASE-T, 10 Mbps Ethernet hub. Up to 25 users can be

supported by connecting to an external eight port-hub.

■ Two analog voice ports.

■ Preferred Provider support which allows simultaneous connections to two

different ISPs.

Routing

■ IP Routing.

■ Dynamic or static IP addresses supplied by the ISP (WAN side).

■ WAN access for up to 25 local workstations on the LAN (10BASE-T).

■ Dynamic Host Control Protocol (DHCP) server functionality on the LAN, which

automatically assigns an IP address to a newly-attached computer on an IP

network.

■ Domain Name Service (DNS) server functionality for the LAN, which translates

the common, alphanumeric name of a device to the numeric IP address of a

device.

■ Network Address Translation (NAT) between LAN and WAN, which allows

multiple users on the LAN to share a WAN connection. Note that individual

email accounts may still be maintained at the ISP.

■ Multiplexing traffic from several computers to the same remote destination.

14 C

HAPTER

1: I

NTRODUCTION

Bandwidth Management

■

Automatic call connection (also known as dial-on-demand routing).

■

Automatic disconnection of idle calls after a specified length of time.

■

Bandwidth on Demand using Bandwidth Allocation Control Protocol (BACP)/Bandwidth Allocation Protocol (BAP) based on a specified threshold.

■

Dynamic bandwidth allocation (DBA), which allows you to place or receive a voice or data call while a Multilink PPP call is active.

■

Manual call connection and disconnection.

Remote Management

■

Remote management using the same Web browser interface.

Voice Features

■

Two analog voice ports for using analog telephone equipment such as touch-tone telephones, fax and answering machines, and analog modems.

■

Flexible call routing to the two analog ports.

■

Caller ID name and telephone display (supports Bellcore GR-30-CORE and SR-TSV-002476 standards).

■

Caller ID Blocking

■

Call Waiting

■

Call Conference (Three-way calling)

■

Call Transfer

■

Call Forward

■

Distinctive Ringing

■

Voice Mail

Protocols

■

IETF PPP (RFC 1661, 1662, 1663).

■

IETF Multilink PPP (RFC 1990).

■

PPTP (Point-to-Point Tunneling Protocol— PPTP draft-ietf-pppext-pptp-02.txt).

■

IETF Password Authentication Protocol (PAP) (RFC 1334) and Challenge Handshake Authentication Protocol (CHAP) security (RFC 1994).

■

MS-CHAP support (as defined in

Microsoft PPP CHAP Extensions. S. Cob, Rev. 1.3 March 1997

Network Working Group Information Memo:

including only

the functionality that keeps with IETF 1994).

■

IP address negotiation using IPCP (RFC 1332).

■

CCP (RFC 1962, 1974).

■

BACP/BAP (RFC 2125).

■

Network Address Translation between LAN and WAN (RFC 1631).

Features 15

ISDN Standards and Interface

■ Basic Rate ISDN U interface with built-in NT1.

■ Full ISDN signaling support of National ISDN.

■ Compatibility with Lucent, Northern Telecom and Siemens switches.

Security

■ PAP, CHAP and MS-CHAP support on both single-channel and Multilink PPP

calls.

Upgradability

■ Flash memory for field firmware updates.

■ Firmware posted on 3Com’s Web site.

Diagnostics

■ LED status display.

■ Statistics display.

Warranty

■ Lifetime Limited Warranty (refer to the back of this User Guide for details).

Internet Applications and Games

Support for applications that use the User Datagram Protocol (UDP) and the Transmission Control Protocol (TCP). The UDP protocol is used primarily by Internet games.

Look for the latest list of Internet applications and games that interoperate with the ISDN LAN Modem at

http://www.remoteaccess.3com.com/support/docs/lanmodem/welcome.html

16 C

HAPTER

1: I

NTRODUCTION

ISDN LAN M

ODEM

Connection Types

LAN Side Connection

UNCTIONALITY

ESCRIPTION

This chapter provides a description of the key functionality of the ISDN LAN Modem. It includes the following topics:

■ Connection Types

■ Call Routing Protocol and IP Address Translation

■ Understanding Multilink PPP and Bandwidth on Demand

■ Understanding Dynamic Bandwidth Allocation

■ Understanding PPTP

For a basic understanding of ISDN and networking, refer to Appendix A.

The ISDN LAN Modem provides LAN side and WAN side connections.

On the LAN side, up to four users can connect to the LAN Modem’s built in Ethernet hub, or up to 25 users may connect to the LAN Modem via an external user-supplied hub, enabling users to share files and printers and to use Internet email. An example of ten workstation connections is shown in An example of 10 workstation connections is shown in Figure 4.

10 Mbps Ethernet LAN

OfficeConnect Hub 8 TPO

Port Status

Network Utilization

3 Com

Office

5678

green = link OK, off = link fail, yellow = partition

1%2% 3% 6% 12%25% 50%80%

Connect Hub

Figure 4

PWR COLLPKT COAX1234

Alert

LAN STATUS

3 Com

OfficeConnect®

Coll

2 3 4

PWR

ISDN

Alert

ISDN LAN Modem

OfficeConnect ISDN LAN Modem

ISDN LAN Modem LAN Connection with 10 Workstations

An example of a single connection is shown in Figure 5.

18 C

2: ISDN LAN M

HAPTER

ODEM FUNCTIONALITY DESCRIPTION

WAN Side Connection

LAN STATUS

2 3 4

Coll

3 Com

Figure 5

OfficeConnect ISDN LAN Modem

PWR

ISDN

Alert

ISDN LAN Modem Single Workstation Connection Example

Application Sharing over the LAN

Most operating systems such as Windows 98 and 95 and Macintosh provide the capability for users on the LAN to share applications, files and printers among computers. For example, if only one computer has a Web browser, the other users on the LAN can use that Web browser to access the Internet. Note that speed will likely be reduced when applications are shared. Refer to your operating system documentation for instructions on setting up sharing between users on a LAN.

The ISDN LAN Modem allows users to connect to a WAN using either of the following methods at one time.

■

Two separate connections to two different locations (one per B channel)

■

One high-speed Multilink PPP connection to a single location (combines both B channels)

Once a WAN connection is established, up to 25 users can share that connection and access the same location simultaneously. If you desire, you can also restrict access to certain users.

Two Separate

Connections to Different

Locations.

An ISDN BRI line has two B channels for transmitting data or voice. Because each B channel is independent, you can connect to two different locations. Once the connection is established, up to 25 users can share either connection. Figure 6 shows one user connecting to a remote office LAN while another connects to the Internet.

Greg's PC

Marcia's PC

Peter's PC

Jan's PC

Figure 6

OfficeConnect ISDN LAN Modem

PWR

ISDN

Alert

LAN STATUS

OfficeConnect™

2 3 4

Coll

ISDN LAN Modem

Greg—64 Kbps B1

3 Com

Peter— 64 Kbps B2

ISDN BRI line

Two Simultaneous Remote Connections to Different Locations

Internet/Intranet or

online service

Greg 64 Kbps B1

Public telephone

network

Peter 64 Kbps B2

Remote office

LAN

Connection Types 19

OfficeConnect

ISDN LAN Modem

Public telephone

network

Remote office

LAN

Combining both B channels with Multilink provides a single 128 Kbps* connection

PWR

ISDN

3 Com

Alert

Coll

2 3 4

LAN STATUS

64 Kbps B1 64 Kbps B2

128 Kbps B1 & B2

*Without compression.

Jerry's PC

Elaine's PC

George's PC

Cosmo's PC

OfficeConnect™

ISDN LAN Modem

Murray

Lou

Mary

PWR

ISDN

3 Com

Alert

Coll

2 3 4

LAN STATUS

OfficeConnect

ISDN LAN Modem

ISDN BRI line

Internet/Intranet or

online service

Mary's PC

Ted's PC

Lou's PC

Murray's PC

Mary

Murray

Lou

Public telephone

network

OfficeConnect™

ISDN LAN Modem

One High Speed

Connection to a Single

Location

Alternatively, the B channels can be combined using Multilink PPP to form one high-speed connection to a single location. Figure 7 shows a single high-speed connection to a remote office LAN.

Figure 7

One High-Speed Connection to a Single Location

Up to 25 users can share a connection to the same location over the single connection created by Multilink PPP. Figure 8 shows three users on the LAN accessing the Internet through the same Internet provider and over the single high-speed connection.

Figure 8

Shared Connection to the Same Location

20 C

2: ISDN LAN M

HAPTER

ODEM FUNCTIONALITY DESCRIPTION

Call Routing Protocol and IP Address Transl ation

Placing a Call to a

Previously Defined

Destination

This section describes the call routing protocol used by the ISDN LAN Modem and explains how IP addresses are translated.

To illustrate how the ISDN LAN Modem routes outgoing data calls, let us assume that you have set up the following types of service providers.

■

A direct connection to an Internet Service Provider

■

A direct connection to a remote office LAN

■

A direct connection to a remote office LAN from which you can also access the Internet

If all of those connection types are configured on the ISDN LAN Modem and are associated with your computer, the following algorithm is performed for each of the following scenarios.

Call Routing While No Other Calls Are Connected

If the ISDN LAN Modem has not established any calls to a remote destination and you want to access the Internet from your computer, you simply launch your Web browser (or whichever networking application you like). When the ISDN LAN Modem receives the information packet requesting access to the WAN, it must determine which connection type to use. The ISDN LAN Modem looks at the destination Network ID (which comprises the destination IP address and subnet mask) associated with the packet. If the Network ID of the packet matches the Network ID of the remote LAN, with or without Internet access, then the call is placed to the remote LAN. If it does not match the Network ID of the remote LAN, with or without Internet access, then the call is routed to the direct ISP connection.

Once the connection is established, any authorized user on the LAN can use this connection. The ISDN LAN Modem will translate each individual user’s IP address into a single, shared IP address (assigned by the remote location), thereby allowing up to 25 users to access the same remote location.

The following example shows three users sharing a connection to the Internet and depicts the IP translation as it occurs in the ISDN LAN Modem.

Understanding Multilink PPP and BACP/BAP 21

198.6.1.1

192.168.1.5

192.168.1.2

192.168.1.4

OfficeConnect® ISDN LAN Modem

192.168.1.1

ISDN BRI line

Internet/Intranet or

online service

PWR

ISDN

3 Com

Alert

Coll

2 3 4

LAN STATUS

Rob's PC

192.168.1.2

Laura's PC

192.168.1.3

Buddy's PC

192.168.1.4

Sally's PC

192.168.1.5

198.6.1.1

IP address assigned by ISP

Translates PC IP addresses to IP address assigned by ISP

ISDN BRI line

Public telephone

network

OfficeConnect™

ISDN LAN Modem

Understanding Multilink PPP and BACP/BAP

Figure 9

IP Address Translation

Call Routing While One Call Is Already Connected

If the ISDN LAN Modem has established a call to a remote destination, for instance, to an ISP, and the ISDN LAN Modem receives more packets, then the ISDN LAN Modem looks at the Network ID of the packets for proper routing. For example, if the Network ID of the packets matches that of the remote LAN and that connection has not yet been established, then the call is placed and the connection is made. If the Network ID does not match and the call type is an Internet access call, then the packets are routed to the ISP.

Note that the ISDN LAN Modem always calls the first configured ISP. If you have configured a second ISP and want to use that one instead, from the ISDN LAN Modem’s configuration home page go to

Workstation Parameters

, select your

computer, and then associate only the ISP that you want to use.

What is Multilink PPP?

Multilink PPP is a protocol which combines multiple point-to-point protocol (PPP) connections to form a single high-bandwidth channel. With a BRI line, Multilink PPP combines the two 56 Kbps or 64 Kbps ISDN B channels, creating a virtual, single connection of up to 112 Kbps or 128 Kbps.

What is BACP/BAP?

BACP/BAP is used in conjunction with the Multilink PPP feature and is transparent to the user (that is, it will not be visible to you as it occurs in the background). You need not configure this functionality. When Multilink PPP is negotiated, the Bandwidth Allocation Control Protocol (BACP) negotiates with the peer equipment to determine whether the peer supports BAP. If the peer supports BAP

22 C

2: ISDN LAN M

HAPTER

ODEM FUNCTIONALITY DESCRIPTION

and agrees to use BAP, then the Bandwidth Allocation Protocol (BAP) negotiates the addition and removal of the second B channel with the peer equipment based on a user-defined threshold. A key advantage of BACP/BAP is that it provides a higher probability of establishing a Multilink PPP call during high traffic conditions by providing a specific telephone number for the second B channel to call.

Multilink PPP Configuration Options

When configuring Multilink PPP, you can choose one of the following options from the ISDN LAN Modem’s Service Provider Parameters window.

■

Use One B Channel When this option is configured, only one B channel is used to connect to this

service provider. Multilink PPP is thereby disabled and BACP/BAP is therefore not used.

■

Use Two B Channels When this option is configured, both B channels are always used to connect to

this service provider, regardless of the amount of traffic over each B channel. Note that when this option is selected, the DBA feature does not work because both B channels are being used. To use both DBA and Multilink PPP, select the option

Add Second B Channel as Required

Understanding Dynamic Bandwidth Allocation

■

Add Second B Channel As Required When this option is configured (referred to as bandwidth on demand) only one

B channel is used to connect to this service provider, and the second B channel is automatically added only when the amount of traffic on the first B channel reaches a threshold you define.

In order for you to use Multilink PPP, the destination you are calling must also support Multilink PPP. For example, if you are trying to dial in to the Internet, your ISP must also support Multilink PPP in order to successfully place a Multilink PPP call. If you attempt to place a Multilink PPP call and the location you are calling does not support Multilink PPP, then a single B channel PPP connection is established.

Dynamic Bandwidth Allocation is used in conjunction with Multilink PPP on demand (to use DBA, you should choose

Add Second B Channel As Required

when you configure Bandwidth Allocation). The Dynamic Bandwidth Allocation feature allows you to automatically and temporarily remove one of the B channels and use it either to place or receive a call (voice or data) without disturbing the original call. The only effect on the original call is that it is reduced from a Multilink PPP call to the speed of one B channel.

Once the interrupting call ends, that B channel is automatically returned to the Multilink PPP call. Although throughput is reduced while the interrupting call is active, the reliability of the Multilink PPP call is maintained.

Understanding VPNs and PPTP 23

From the Edge to the Heart

of the Network.

POWER

ISDN

Alert

B2 TX COLL 1 2 3 4

3 Com

LAN STATUS

ISDN LAN Modem

3C892

Internet Service

Provider

LAN Modem

Tunnel

terminator

Corporate

network

Understanding VPNs and PPTP

Virtual private networks (VPN) are private, secure networks created in public networks such as the Internet. A VPN is essentially a secure, private tunnel within the Internet. Since VPN calls are placed through a local ISP, they eliminate long distance charges that would occur from directly dialing to a remote private network.

One of the protocols which enables a VPN to be created is PPTP. The PPTP protocol allows for multiple workstations to establish a secure multi-protocol connection to a remote, private network via a single, locally-dialed ISP account as shown in Figure 10. Any networking protocols such as IP, IPX and NetBEUI can be supported transparently through the tunnel. While the ISDN LAN Modem supports PPTP, it does not play an active role in creating or terminating a tunnel.

Figure 10

Connection to an Remote Private Network via an ISP

Setting Up the Server

Side of the Tunnel

Setting Up the Client

Side of the Tunnel

The main steps for creating a VPN are as follows. Each step is explained in detail in subsequent sections.

■ Set up the server side of the tunnel connection

■ Set up the client side of the tunnel connection

■ Initiate a tunnel between client and server using your client software

In order to establish a tunnel, the client side must be able to dial into a PPTP tunnel server on the remote private network such as 3Com’s NETBuilder, PathBuilder, and Total Control Hub as well as Microsoft’s Windows NT server version 4.0 or later. If you use Windows NT 4.0, then Service Pack 3 or greater and RAS must be installed. Also, the protocols required for the private network must be installed on the PPTP tunnel server. It is recommended that an experienced network administrator set up the server side. Note that protocols required for the private network must be installed on each PPTP tunnel client as well as the PPTP tunnel server.

In order to establish a tunnel, the client side must have PPTP tunnel client software such as Windows Dial-Up Networking version 1.2 or higher which includes the required software VPN adapter or Windows NT operating system with Service Pack 3, or Network TeleSystem’s TunnelBuilder™ VPN software for Windows 3.11 and Macintosh operating systems. This software should reside on all workstations that wish to create a tunnel to the tunnel server. Follow instructions provided for installation and set up.

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HAPTER

ODEM FUNCTIONALITY DESCRIPTION

For Windows Dial-Up Networking Users

If you are using Windows Dial-Up Networking version 1.2 or higher, the basic set up steps are as follows. (Refer to Windows user documentation for details.)

■

Install the PPTP protocol

■

Create a RAS phone book entry for the VPN A RAS phone book entry is similar to other phone book entries except there is

an IP address in the Phone number field. Once the Phone book entry is complete, you can double-click the icon to dial into a server that supports PPTP via any ISP.

Note that protocols required for the private network must be installed on each PPTP tunnel client as well as PPTP tunnel server.

Establishing a Tunnel via

the ISDN LAN Modem

As with PPP, no configuration is required on the LAN Modem to use PPTP. However, you must have an ISP configured on the LAN Modem.

Once the client side and server side are configured, you are ready to create a tunnel. The steps required for creating a tunnel vary depending on which client software you are using. Refer to the user documentation provided with your PPTP software to determine how to establish a tunnel. For instance, if you are using Windows Dial-Up Networking version 1.2 or higher, double-click the phone book entry for the VPN.

Once you attempt to create a tunnel, the ISDN LAN Modem detects this attempt and automatically places a call to your ISP. Once the call is connected, a tunnel is established between your workstation and the tunnel server.

You are ready to access a remote private network LAN as if you were connected locally. Each workstation that wishes to have access to the remote private LAN will need to create its own tunnel.

For more information, refer to:

http://www.remoteaccess.3com.com/support/docs/lanmodem/ welcome.html For specific instructions on how to configure a VPN adapter in

Windows 98, 95 or Windows NT, refer to Microsoft’s Web site at http://www.microsoft.com. and then enter PPTP in the search field.

ARDWARE

ESCRIPTION AND

Package Contents

Before You Install the ISDN LAN Modem

NSTALLATION

The ISDN LAN Modem package includes:

■ OfficeConnect ISDN LAN Modem

■ Power cable with an AC wall transformer

■ RJ -11 ISDN telephone cable

■ 10BASE-T Ethernet cable

■ 3Com Companion Programs CD-ROM

■ OfficeConnect ISDN LAN Modem Getting Started Guide

■ Rubber feet and stacking clips

To install, configure and use the ISDN LAN Modem successfully, you must have the following:

■ Correct ISDN service installed at your location with an available ISDN RJ-11 or

RJ-45 outlet. If you have not yet ordered ISDN service, refer to Appendix E.

■ A JavaScript-enabled and frames-capable Web browser. A Web browser is

provided on the 3Com Companion Programs CD-ROM. (For more information

refer to Appendix B.) If you use a different Web browser, make sure that it

supports frames such as Netscape 2.1 and later and Internet Explorer 3.0 and

later.

If you already have a version of the Internet Explorer Web browser installed and would like to install a later version, you should first uninstall the previous version. If you are asked to replace the older files, it is recommended that you do so.

■ A personal computer with TCP/IP and Ethernet connectivity that meets UL

standards in the United States or is certified to CSA standards in Canada.

For a PC, a 386 or higher processor is recommended and a 10BASE-T

■

Ethernet card is required. For an Apple Macintosh computer, system 7.6 or later operating system and

■

Open Transport (provided as part of system 7.5). Built-in Ethernet connectivity is provided through an Apple Ethernet port in all Power Macintosh computers.

TCP/IP is provided as part of the Windows 98, 95, NT and Macintosh System

■

7.6 and later operating systems. For Windows 3.11 users, TCP/IP software is provided on the 3Com Companion Programs CD-ROM.

You do not have to have available storage space on your computer’s hard drive because nothing is copied as part of the ISDN LAN Modem installation. If you want to copy any programs or documents from the CD-ROMs, ensure that you have available hard disk space.

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ARDWARE DESCRIPTION AND INSTALLATION

Front Panel LED Description

The front panel provides the following LEDs.

Alert

Figure 11

ISDN

B2 TX COLL 1 2 3 4

POWER

ISDN LAN Modem Front Panel

LAN STATUS

ISDN LAN Modem

3C892

3 Com

The functions of the front panel LEDs are described in Table 4. These front panel LEDs show whether or not the unit is functioning properly and indicate the status of the activity over the 10BASE-T and ISDN ports.

Table 4

LED Color Description

Alert Amber

POWER Green

ISDN OK

B1/B2 Amber or

Tx Green

Coll Amber

Ports1—4 Green

Front Panel LED Indicator Definitions

Operational Status. Lit during power-on self-test diagnostic or after pressing the reset button.

Off indicates the unit has passed the diagnostic tests and is working properly.

Flashes (four times per second) if one or more of the diagnostics have failed or after the unit is placed in firmware download mode and is waiting for a firmware upgrade.Flashes (once per second) to indicate there are pending voice mail messages.

Power Indicator. Remains lit as long as power is supplied to the unit.

Green D Channel Status. Indicates the status of the ISDN physical

network interface and D channel. Remains lit once the physical ISDN interface and D channel

signaling are synchronized. Off indicates the physical ISDN interface is not synchronized or is

disconnected. Flashes when the physical interface attempts synchronization or

when the ISDN D channel parameters have changed. B1/B2 Channel Activity. Green indicates a data call in progress.

Green

Amber indicates a voice call in progress. If a call is in a dialing state, the LED flashes. When the call is disconnected, the LED goes off.

Ethernet Transmit Status. Flashes green when data is being transmitted to the Ethernet LAN from the ISDN LAN Modem.

Off indicates no data is being transmitted to the Ethernet LAN from the ISDN LAN Modem.

Ethernet Collision Status. Flashes amber when some collisions are taking place on the Ethernet LAN.

Off indicates no collisions are taking place on the Ethernet LAN. Ethernet LAN Port Status. On indicates the unit detects the

Ethernet link integrity signal from an attached computer and operation is normal.

Flashes when the LAN Modem is receiving data on that port. Off indicates the unit does not detect the Ethernet link integrity

signal. The Ethernet cable may not be properly connected or the cable may be the wrong polarity.

Installing the ISDN LAN Modem 27

RESET

10-18 VDC

0.8 A MAX

ISDN

1 PHONE 2

LAN

Power

Connector

Reset Button

Two Analog

Telephone Ports

Four Ethernet

10Base-T Connectors

ISDN

BRI Interface

Back Panel Connector

Description

The back panel provides the following components.

Figure 12

ISDN LAN Modem Back Panel

From left to right the back panel consists of the following.

Power: Connect the power module cable to this port.

■

Reset: Press this button for no more than a couple of seconds if you have to

■

reset the unit. This causes the software to restart while maintaining your

configuration profile which includes service provider information and ISDN line

telephone numbers.

Two Analog Telephone Ports: You can connect analog equipment such as a

■

fax machine or telephone to these ports.

Four 10BASE-T Ethernet Ports: Connect the computers to these ports or

■

another Ethernet hub to add up to 25 users.

Installing the ISDN LAN Modem

Before You Begin

ISDN Basic Rate Interface Port: Connect the ISDN cable to this port.

■

This section describes how to do the following.

■ Install the ISDN cable

■ Connect to a 10BASE-T Ethernet LAN

■ Install analog equipment

■ Install the power cable

Before you begin, you will need the following in addition to the ISDN LAN Modem which was provided in the package:

■ RJ-45 (8-pin) to RJ-11 (6-pin) cable labeled ISDN which was provided in the

package.

■ 10BASE-T Ethernet cable (8-pin to 8-pin connectors) labeled Ethernet which

was provided in the package. It is recommended that you use the cable

provided. If, however, you choose to use another cable it must be a

straight-through 10BASE-T Ethernet cable. It cannot be a crossover cable.

■ Power adapter provided (you must use the power adapter provided in the

package).

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ARDWARE DESCRIPTION AND INSTALLATION

Installing the ISDN Cable

To install the ISDN cable: Connect the RJ-45 (8-pin) connector end of the ISDN cable to the port labeled

ISDN on the back panel, as shown in Figure 13.

ISDN

1 PHONE 2

RESET

10-18 VDC

0.8 A MAX

Figure 13

Connect the RJ-11 (6-pin) connector end of the RJ-45/RJ-11 ISDN cable to the

ISDN Cable Connection

RJ-11 or RJ-45 ISDN wall jack.

CAUTION: An NT1 (that is, a network termination device) is built into the ISDN LAN Modem. Never connect the ISDN LAN Modem ISDN port to a standard analog telephone jack or to an external NT1 device. Make sure that the ISDN cable is connected directly to the ISDN jack.

Connecting to a

10BASE-T Ethernet Port

To connect a computer to the ISDN LAN Modem, do the following.

Insert one end of the 10BASE-T Ethernet cable into one of the four LAN ports on

the back of the ISDN LAN Modem, as shown in Figure 14.

ISDN

1 PHONE 2

RESET

10-18 VDC

0.8 A MAX

Figure 14

Insert the opposite end of the cable into your computer’s 10BASE-T Ethernet port.

10BASE-T Ethernet LAN Connection

Installing the ISDN LAN Modem 29

Connecting to Another

Ethernet Hub

CAUTION:

You should only have one computer physically connected to the ISDN LAN Modem during configuration. Once you complete the configuration process, connect any other computers you would like to have on the LAN and then power cycle each computer. If the newly-added computers cannot communicate with the ISDN LAN Modem, refer to “Evaluating Symptoms and Solutions” in Chapter 9.

You can connect to another Ethernet hub to allow up to 25 users to access the WAN. Instructions for adding another Ethernet hub to allow 10 users, a more common scenario, is as follows.

Before You Begin

In addition to an external 10BASE-T Ethernet hub, you will need a 10BASE-T Ethernet cable, which may have been provided with the additional hub. If the hub to which you are connecting your LAN Modem does not have an MDI/X switch, you must use a crossover cable.

Insert one end of the 10BASE-T Ethernet cable into one of the four LAN ports on

the back of the ISDN LAN Modem, as shown in Figure 15.

ISDN

10-18 VDC

0.8A MAX

RESET

1 PHONE 2

10-18 VDC

0.8A MAX

Figure 15

Insert the opposite end of the cable into a 10 BASE-T Ethernet port on the other

10BASE-T Hub-to-Hub Connection

87654321

MDI/MDIX

Ethernet hub. If you are connecting to an OfficeConnect Hub 8/TPO, insert the opposite end of

the Ethernet cable into port 8 and then set the MDI/X switch to MDI (that is, pressed in). Make sure that the LED associated with that Ethernet port is lit. If it is not, try changing the MDI/X switch setting.

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Installing Analog

Equipment

You can connect an analog touch-tone telephone, answering machine, fax machine, or external analog modem to the ISDN LAN Modem. You will need an RJ-11 to RJ-11 cable that is supplied with the analog device for each analog phone port connection.

To install an analog device:

Insert one end of an RJ-11 cable into one of the two analog ports labeled Phone

on the back of the ISDN LAN Modem, as shown in Figure 16.

ISDN

1 PHONE 2

RESET

10-18 VDC

0.8 A MAX

Figure 16

Insert the other end of the RJ-11 cable into the appropriate RJ-11 port on the

Analog Equipment Connection

analog device. If you have another analog device to install, repeat steps 1 and 2.

CAUTION: The ISDN LAN Modem is designed to operate with touch-tone telephones that collectively do not exceed a ringer equivalence number (REN) of three per analog phone port. The ISDN LAN Modem is designed to provide power (25 mA loop current per phone port) and ringing for these devices on up to 61 meters (200 feet) of AWG 26 or heavier AWG wiring. Although the ISDN LAN Modem may function satisfactorily at longer cable distances with more than two attached telephones, proper operation at longer cable distances is not guaranteed in all situations.

Specialized telephone equipment such as speaker phones that draw large amounts of power may not work on the ISDN LAN Modem’s Phone port. Because these devices do not conform to the power specification of the touch-tone telephone standard, their operation is not guaranteed.

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