3COM 3C886 User Manual

OfﬁceConnect

56K LAN Modem

3C886

User Guide

http://www.3com.com/

Part No. 984/000027-2 Published March 1999

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

Copyright © 3Com Corporation, 1999. All rights reserved. No part of this documentation may be reproduced in any form or by any means or used to make any derivative work (such as translation, transformation, or adaptation) without permission from 3Com Corporation.

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: Use, duplication, or disclosure by the Government is subject to restrictions as 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: Use, reproduction, or disclosure is subject to restrictions set forth in 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 Unpublished rights reserved under the copyright laws of the United States.

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

3Com and OfﬁceConnect are registered trademarks of 3Com Corporation. IBM is a trademark of International Business Machines Corporation. Macintosh is a registered trademark of

Apple Computer Corporation. UL is a trademark of Underwriters Laboratory, Inc. Pentium is a registered trademark of Intel Corporation. Windows and Windows NT are registered trademarks of Microsoft Corporation. LZS is a registered trademarks of Stac, Inc. Compuserve is a registered trademark of Compuserve Interactive Services, Inc. 3ComFacts is a service mark of 3Com.

Other brand and product names may be registered trademarks or trademarks of their respective holders. Guide written by Eric Heller

Additional Safety Information

MPORTANT

AFETY

NFORMATION

WARNING: Warnings contain directions that you must follow for your personal safety . Follow

all instructions carefully.

Please read the following information carefully and thoroughly before installing the unit:

■

Take exceptional care during the installation and removal of the unit. Use the power adapter supplied with the unit to ensure compliance with national safety

■

standards.

■

Disconnect the power adapter before moving the unit. Power can only be disconnected from the unit by removing the power adapter from the unit or from the socket outlet.

There are no user-replaceable fuses or user-serviceable parts inside the unit. If there is a

■

physical problem with the unit that cannot be solved with problem solving actions in this guide, contact the 3Com reseller from whom the equipment was purchased.

■

If the units are stackable, only stack similar units.

Only connect apparatus complying with the relevant interface requirements to the ports on

■

this unit.

■

Retain this user’s guide for later use and pass it on in the event of change of ownership of the unit.

Protect the unit from sudden, transient increases and decreases in electrical power by fitting

■

an in-line surge suppressor or uninterruptable power supply. Products manufactured by us are safe and without risk provided they are installed, used and maintained in good working order in accordance with our instructions and recommendations.

If any of the following conditions occur, isolate the electricity supply and refer to your 3Com

■

reseller.

If the case or cover is not correctly fitted or if it is damaged.

■

If the unit begins to make an odd noise, smell or smoke.

■

If the unit shows signs of a distinct change in performance.

Never install telephone wires during a lightning storm, or install telephone connection

■

sockets in wet locations, unless the socket is specifically designed for wet locations.

■

Do not touch uninstalled telephone wires or terminals unless the telephone line has been disconnected at the network interface. Always exercise caution when installing or modifying telephone lines.

Do not use a telephone, which is connected to the unit, to report a gas leak in the vicinity of

■

the leak.

■

Do not spill food or liquids on the unit. If the unit gets wet, isolate the electrical supply and contact your 3Com reseller.

Do not push any objects into the openings of the unit. Doing so can cause fire or electric

■

shock by shorting out internal components.

■

Only equipment approved for use by your telephone company can be connected to the telephone port.

■

Avoid using a telephone, which is connected to the unit (other than a cordless type), during an electrical storm.

■

Equipment connected to the telephone port must be located in the same building as the unit.

■

Be sure nothing rests on the unit’s system cables and that the cables are not located where they can be stepped on and cause damage to the unit.

Keep the unit away from radiators and heat sources. Allow 1 inch (25mm) around the unit

■

to provide adequate air circulation.

■

Install the unit in a clean area that is free from dust or extreme temperatures.

■

Allow a clearance gap of at least a 6 inches (150 mm) from the rear panel of the unit, to allow for cable access.

■

Interconnecting directly, or by way of other apparatus, to ports complying with SELV requirements may produce hazardous conditions on the network. Advice should be sought from a competent engineer before such a connection is made.

ABLE

MPORTANT

Additional Safety Information 3

BOUT

Introduction 11 How to Use This Guide 11 Conventions 11 Year 2000 Compliance 12

NTRODUCTION

Introduction 13

56K Access 13

Applications 13

Local Networking with Access to the Internet 14 Local Networking with Access to a Remote Ofﬁce 14

Features 15

Ease of Installation and Use 15 High Performance 15 Connectivity 15 Routing 15 Bandwidth Management 15 Remote Management 15 Protocols 16 Error Control and Data Compression 16 Modulation Schemes 16 Security 16 Upgradability 16 Diagnostics 16 Warranty 17 Support for Internet Applications 17

HIS

AFETY

UIDE

ONTENTS

NFORMATION

56K LAN M

UNCTIONALITY

Connection Types 19

56K Technology 19 LAN Side Connection 19

Application Sharing over the LAN 20

ODEM

ESCRIPTION

WAN Connection 21 One High Speed Connection 21 Sharing the Connection 21

Call Routing Protocol and IP Address Translation 22

Placing a Call to a Previously Deﬁned Destination 22

Call Routing While No Other Calls are Connected 22

Understanding VPNs and PPTP 23

Setting Up the Server Side of the Tunnel 24 Setting Up the Client Side of the Tunnel 24

For Windows Dial-Up Networking Users 24

Establishing a Tunnel via the LAN Modem 24

ARDWARE

Package Contents 27 Before You Install the 56K LAN Modem 27 Front Panel LED Description 28

Back Panel Connector Description 29

Installing the 56K LAN Modem 29

Before You Begin 29 Installing the Analog Cable 30 Connecting to a 10BASE-T Ethernet Port 30 Connecting to Another Ethernet Hub 31

Before You Begin 31

Installing Analog Equipment 32

Installing the Power Cable 32

ESCRIPTION

AND

NSTALLATION

ETTING

TCP/IP Setup Using Windows 95 and 98 35 TCP/IP Setup Using Windows NT 4.0 38 TCP/IP Setup Using Mac OS 7.6 or later 41 TCP/IP Setup Using Windows 3.11 42

ONFIGURING

Typical Conﬁguration 45

TCP/IP

Setting up TCP/IP using MS_TCP 42

THE

56K LAN M

Before You Begin 45 You Should Have This Information 46 Determine Whether You Use Dynamic or Static IP Addresses 46 Setting Up Your Computer If You Have a Static IP Address 47

For Windows 98 and 95 Users 47 For Windows NT 4.0 Users 47 For Macintosh Users 48

For Windows 3.11 Users 48 Conﬁguring the 56K LAN Modem for the Typical Conﬁguration 49 Conﬁguring a Static IP Address on the 56K LAN Modem 52 Conﬁgure Additional Parameters 53

FOR

INDOWS

ODEM

AND

ACINTOSH

56K LAN Modem Main Page 54

Links From the Illustration 54 Links from the Buttons 55

DVANCED

Advanced Conﬁguration 57 Setting Up Additional Service Providers 57

ISP Versus Private Network 58

When to Select ISP 58 When to Select Private Network 58

Setting Up a Connection to an ISP 58

Before You Begin 58 Setting Up a Connection to the Internet 59

Setting Up a Connection to a Private Network 62

Before You Begin 62

Setting Up a Connection to a Remote LAN 62 Associating Service Providers with Computers on the LAN 65 Editing Service Provider Proﬁles 66

Restricting Access to Service Providers 66

Conﬁguring LAN Parameters 67

Understanding LAN Parameters 67

Name 67

IP Address and Subnet Mask 67

Local Domain Name 68

Enable DHCP Server 68

Enable NetBIOS Filtering 68

Conﬁguring the LAN Parameters 68

Conﬁguring Modem Control Parameters 69

Understanding Modem Controls 69

Connection Controls 69

Mode Controls 69

Protocol Controls 69

Changing Modem Controls 70

Changing Data Call Parameters 71

Understanding Data Call Parameters 71

Minimum Call Duration 71

Disconnecting an Automatic Data Call 71

Disconnecting a Manual Data Call 72

Number of Times to Redial for a Manual Call 72

Delay Between Redial Attempts When Placing a Manual Call 72

Conﬁguring the Data Call Parameters 72 Selective Password Protection 72 Changing Your Password 73

What If I Forget My Password? 73 Locking and Unlocking the Conﬁguration 73 Conﬁguring the LAN Modem from a Remote Location 74

Conﬁguring the LAN Modem Remotely via Another LAN Modem 74

ONFIGURATION

Conﬁguring the LAN Modem Remotely via an Analog Modem 74

LACING

Placing Calls 77

Placing a Call Automatically 77

Call Routing Among Service Providers 77 Placing a Call Manually 78 Placing a Call Manually to a Temporary Service Provider 78

Receiving Calls 79

Receiving Voice Calls 79 Receiving Data Calls 79 Auto Answer 79

Disconnecting Calls 80

Disconnecting Calls Manually 80 Disconnecting Calls Automatically Using Timers 80

Minimum Call Duration 80

Idle Timeout 80

Using a Connection Script 80

Before You Begin 80 Accessing the Script Conﬁguration Page 81 Creating a Connection Script 82

Connection Script Command Syntax 82 Using the Conﬁguration Buttons 82

Additional Conﬁguration Buttons 84

ECEIVING

, R

AND

ISCONNECTING

ALLS

ROUBLESHOOTING

Checking the Basics 85 Monitoring LEDs 85

Monitoring the ALERT LED 85 Monitoring the LAN Port Status LEDs 86

Evaluating Symptoms and Solutions 86 Finding More Information 90 Contacting Technical Support 90 Downloading Firmware to Your 56K LAN Modem 90 Resetting the 56K LAN Modem to a Factory Default Setting 90

Resetting the 56K LAN Modem to the Factory Defaults 90

Reviewing Statistics 91

Understanding System Statistics 91 Understanding Current Call Information 91 Understanding Last Call Information 92 Understanding Service Provider Information 93

AND

AINTENANCE

ETWORKING

RIMER

General Speciﬁcations 105 Year 2000 Compliance 105

THE

USTOM

EFAULTS

SING

ACTORY

PECIFICATIONS

LOSSARY

OM CORPORATION LIMITED WARRANTY

FCC CLASS B STATEMENT

FCC DECLARATION OF CONFORMITY

ROWSER

ABOUT THIS GUIDE

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

Introduction This guide describes how to install and conﬁgure the 56K LAN Modem and

provides descriptions of key applications and networking concepts.

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

How to Use

This table shows where to ﬁnd speciﬁc information in this guide.

This Guide

Table 1 Speciﬁc Information

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

An overview of the 56K LAN Modem Chapter 1 An explanation of the 56K LAN Modem’s key functionality Chapter 2 A description of the 56K LAN Modem’s hardware components Chapter 3 Instructions on setting up TCP/IP Chapter 4 Instructions for basic configuration of the 56K LAN Modem software Chapter 5 Instructions for advanced configuration Chapter 6 Information on placing, receiving and disconnecting calls Chapter 7 Information on troubleshooting and maintenance Chapter 8 Background information on networking Appendix A Information on using the custom browser Appendix B 56K LAN Modem factory default settings Appendix C Technical specifications for the 56K LAN Modem Appendix D Glossary definitions for terms used in this guide Glossary

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

Table 2 Notice Icons

Icon Notice Type Alerts you to...

Information note Important features or instructions

Caution Risk of personal safety, system damage, or loss of data

Warning Risk of severe personal injury

12 ABOUT THIS GUIDE

Table 3 Text Conventions

Convention Description

Commands The word “command” means you must enter the command exactly as

shown in text and press the Return or Enter key. Example:

To remove the IP address, enter the following command:

SETDefault!0 -IP NETaddr = 0.0.0.0

NOTE: This guide always gives the full form of a command in

uppercase and lowercase letters. However, you can abbreviate commands by entering only the uppercase letters and the appropriate value. Commands are not case-sensitive.

The words “enter” and “type”

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

[Key] names Key names appear in text in one of two ways:

■ Referred to by their labels, such as “the Return key” or “the Escape

key”

■ Written with brackets, such as [Return] or [Esc].

If you must press two or more keys simultaneously, the key names are linked with a plus sign (+). Example:

Press [Ctrl]+[Alt]+[Del].

Menu commands and buttons

Words in italicized type

Words in bold-face

Menu commands or button names appear in italics. Example:

From the Help menu, select Contents.

Italics emphasize a point or denote new terms at the place where they are defined in the text.

Bold text denotes key features.

type

Year 2000 Compliance The OfﬁceConnect 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.3com.com/products/yr2000.html

INTRODUCTION

This chapter provides an overview of the OfﬁceConnect® 56K LAN Modem, referred to throughout this document as the 56K LAN Modem or simply as the LAN Modem.

Introduction The 56K LAN Modem is an easy to install, Local Area Network (LAN) to Wide Area

Network (WAN) personal analog IP router. The LAN Modem provides four built-in 10BASE-T Ethernet connections for the LAN, while utilizing the V.90 ITU 56K standard for WAN access. Combining the 56K LAN Modem with an additional external hub allows total WAN connectivity for up to 25 users.

With the 56K LAN Modem, small ofﬁce and home ofﬁce users can share remote access to the Internet or to a corporate LAN while continuing to network locally.

56K Access 33.6 Kbps was once thought to be the practical limit for speed over standard

analog phone lines. Now, the V.90 56K ITU standar d pr ovides download speeds of up to 56K. upgrades to new features and enhancements as they become available.

And your 56K LAN Modem is software upgradable, allowing easy

For further information, visit 3Com’s 56K web site at

Applications The primary applications for the 56K LAN Modem are:

■ Local networking with shared access to the Internet

■ Local networking with shared access to a remote ofﬁce LAN

1.Capable of receiving at up to 56 Kbps and sending at up to 33.6 Kbps. Due to FCC regulations, receiving speeds are limited to 53 Kbps. Actual speeds may vary . Requires compatible phone line and server equipment. The 56K LAN Modem complies with the V.90 ITU standard and is backwards compatible with all US Robotics 56K standards. Standard ofﬁcially determined in February, 1998; ratiﬁcation expected in September, 1998.

http://www.3com.com/56k.

14 CHAPTER 1: INTRODUCTION

Local Networking with

Access to the Internet

Users can share access to the Internet while continuing to network locally, as shown in Figure 1.

PWR COLLPKT COAX1234

Alert

OfficeConnect Hub 8 TPO

Port Status

5678

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

Network Utilization

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

3 Com

Office

Connect Hub

OfficeConnect 56K LAN modem

LAN STATUS

PWR

Coll

Alert

OfficeConnect™

2 3 4

ISDN LAN Modem

3 Com

Analog POTS line

Internet/Intranet

online service

Public telephone

network

Local Networking with

Access to a Remote

Ofﬁce

Figure 1 Local Networking with Internet Access

Users can share access to a remote ofﬁce LAN while continuing to network locally, as shown in Figure 2.

OfficeConnect™ 56K LAN Modem

Figure 2 Local Networking with Access to a Remote Ofﬁce LAN

Features Ease of Installation and Use

■ Web-based, point-and-click user interface for easy conﬁguration

■ Automatic Internet conﬁguration veriﬁcation via your Internet Service Provider

(ISP)

■ Web-based, context-sensitive online help

High Performance

■ Internal 56K modem, capable of transmitting at speeds up to 33.6 Kbps and

downloading at speeds up to 56 Kbps

■ V.42/MNP 2-4 error control and V.42 bis/MNP 5 data compression

■ Hi/fn™ LZS

Compression Control Protocol (RFC 1962) and PPP Stacker LZS Compression Protocol (RFC 1974)

Connectivity

■ One 56K integrated analog modem

■ 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

compression, which conforms to the following IETF RFCs: The PPP

(without compression)

Features 15

■ One pass through analog voice port for connecting an external analog device

Routing

■ IP Routing

■ Dynamic or static IP addresses supplied by your service provider (WAN side)

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

which automatically assigns an IP address to a newly-attached PC on the IP network

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

the common, alphanumeric name of a device (for example, “www.3com.com”) to its numeric IP address

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

multiple users on the LAN to share a single remote connection

■ Multiplexing trafﬁc from several computers to the same remote destination

■ LAN access to the Internet using a single-user account

Bandwidth Management

■ Dial on Demand (Automatic call connection)

■ Automatic disconnection of idle calls after a user-speciﬁed length of time

■ Manual call connection and disconnection

Remote Management

■ Remote management via Web browser-based interface

■ Remote ﬁrmware upgrades

1.Current FCC rules limit download speeds to 53Kbps.

16 CHAPTER 1: INTRODUCTION

Protocols

■ IETF PPP (RFC 1661, 1662, 1663)

■ IETF Password Authentication Protocol (PAP) and Challenge Handshake

Authentication Protocol (CHAP) security (RFC 1994)

■ MS-CHAP support (as deﬁned in Network Working Group Information Memo:

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

the functionality that keeps with IETF 1994).

■ IP address negotiation using IPCP (RFC 1332)

■ Network Address Translation (NAT) between LAN and WAN (RFC 1631)

■ Point-to-Point Tunneling Protocol (PPTP)

Error Control and Data Compression

■ ITU-T V.42

■ ITU-T V.42bis

■ MNP 2-5

Modulation Schemes

■ V.90

■ Backwards compatible with all US Robotics 56K Standards

■ ITU-T V.34+

■ ITU-T V.34

■ ITU-T V.32bis

■ ITU-T V.32

■ ITU-T V.22bis

■ ITU-T V.22

■ ITU-T V.23

■ Bell 212A

■ ITU-T V.21

■ Bell 103

Security

■ PAP CHAP and MS-CHAP support

Upgradability

■ Flash memory for ﬁeld ﬁrmware updates

■ Firmware posted on 3Com’s Web site

■ Fully upgradable to future 56K standards

Diagnostics

■ LED status display

■ Statistics display

Features 17

Warranty

■ 3Com Corporation Limited Warranty (refer to the end of this User Guide for

details)

Support for Internet Applications

Your 56K LAN Modem supports applications that use the User Datagram Protocol (UDP) and the Transmission Control Protocol (TCP). This protocol is used primarily by Internet games.

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

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

18 CHAPTER 1: INTRODUCTION

56K LAN MODEM

Connection Types This section discusses LAN side and WAN side connections.

56K Technology Your 56K LAN Modem utilizes the V.90 56K ITU standard, which is backward

UNCTIONALITY DESCRIPTION

This chapter provides a description of the 56K LAN Modem’s key functionality, covering the following topics.

■ Connection Types

■ Call Routing Protocol and IP Address Translation

■ Understanding PPTP

compatible with all US Robotics 56K standards, and is capable of download speeds of up to 56K conﬁguration found when an analog modem dials into a digitally connected Internet Service Provider. Because it requires no analog-to-digital conversions in the downstream path (which can cause line noise), V.90 can use nearly all of the available 64K network bandwidth. (Upstream data, typically less speed sensitive, travels at the standard V.34 rate.)

. V.90 technology takes advantage of the typical network

Further information is available in Appendix A of this User Guide, or visit the 56K web site at

LAN Side Connection On the LAN side, up to four users can connect to the 56K LAN Modem’s built in

Ethernet hub, or up to 25 users may connect to the 56K 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 Figure 3.

1.Capable of receiving at up to 56 Kbps and sending at up to 33.6 Kbps. Due to FCC regulations, receiving speeds limited to 53 Kbps. Actual speeds may vary. Requires compatible phone line and server equipment. The 56K LAN Modem complies with the V.90 ITU standard and is backwards compatible with all US Robotics 56K standards. Standard ofﬁcially determined in February, 1998; ratiﬁcation expected in September, 1998.

http://www.3com.com/56k.

20 CHAPTER 2: 56K LAN MODEM FUNCTIONALITY DESCRIPTION

10 Mbps Ethernet LAN

OfficeConnect Hub 8 TPO

Port Status

PWR COLLPKT COAX1234

5678

Alert

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

Network Utilization

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

3 Com

Office

Connect Hub

LAN STATUS

Coll

PWR

Alert

OfficeConnect 56KLAN Modem

3 Com

OfficeConnect®

2 3 4

56K LAN Modem

Figure 3 56K LAN Modem Ten Workstation Connection Example

An example of the minimum number of connections is shown in Figure 4.

3C886

56K LAN Modem

Figure 4 56K LAN Modem Minimum Connection Example

Application Sharing over the LAN

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

Connection Types 21

OfficeConnect

56K LAN Modem

Public telephone

network

Remote office

LAN

Analog connection

3 Com

Oscar’s

Analog connection

Oscar’s PC

Felix’s PC

Murray’s PC

Myrna’s PC

connection

3C886

56K LAN Modem

PWRAA RD SD

Alert

Tx Coll 1 2 3 4 CD OH

LAN STATUS

OfficeConnect

56K LAN Modem

Public telephone

network

Remote office

LAN

Shared analog connection

Mike

Single analog connection

Mike’s PC

Gloria’s PC

Edith’s PC

Archie’s PC

Gloria

3 Com

3C886

56K LAN Modem

PWRAA RD SD

Alert

Tx Coll 1 2 3 4 CD OH

LAN STATUS

WAN Connection The 56K LAN Modem allows up to 25 users to connect to a WAN using one

analog connection to a single location.

One High Speed

Connection

The WAN connection may be utilized by a single user to connect to a remote site such as a corporate LAN, as shown in Figure 5.

Figure 5 Single User Connecting to a Remote Site

Sharing the Connection Once the call is established, up to four users may share the single connection

created by the call over the LAN Modem’s four-port built in hub. Or, up to 25 users may share this connection over an external hub. Figure 6 shows two users on the LAN accessing the Internet through the same Internet provider and over the same connection. If you desire, you may also restrict access to certain users. Note that speed may be affected with multiple users downloading simultaneously.

Figure 6 Shared Connection to a Remote Site

Your 56K LAN Modem is capable of supporting WAN access for up to 25 users. However, for improved performance it is recommended that no more than four users attempt to share a single connection at one time.

22 CHAPTER 2: 56K LAN MODEM FUNCTIONALITY DESCRIPTION

Call Routing Protocol and IP Address Translation

Placing a Call to a

Previously Deﬁned

Destination

This section describes the call routing protocol used by the 56K LAN Modem and explains how IP addresses are translated.

The 56K LAN Modem distinguishes between three types of destinations:

■ A direct connection to an Internet Service Provider

■ A direct connection to a Remote Ofﬁce LAN

■ A direct connection to a Remote Ofﬁce LAN with Internet Access

If all of these connection types are conﬁgured on the 56K 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 56K 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 56K LAN Modem receives the information packet requesting access to the WAN, it must determine which connection type to use. The LAN Modem looks at the destination Network ID (destination IP address and subnet mask) associated with the packet. If the Network ID of the packet matches the Network ID of the Remote Ofﬁce 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 56K LAN Modem will translate each individual user’s local IP address into a single, shared IP address (assigned by the r emote location), allowing shared access to the remote location. The following example shows three users sharing a connection to the Internet and depicts the IP address translation as it occurs in the LAN Modem.

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

Jack’s PC

192.168.1.2

Chrissy’s PC

192.168.1.3

Larry’s PC

192.168.1.4

Janet’s PC

192.168.1.5

192.168.1.2

192.168.1.4

192.168.1.5

Translates PC IP addresses to IP address assigned by ISP

LAN STATUS

PWRAA RD SD

Tx Coll 1 2 3 4 CD OH

Alert

OfficeConnect 56K LAN Modem

192.168.1.1

3C886

56K LAN Modem

IP address assigned by ISP

198.6.1.1

3 Com

Analog POTS line

198.6.1.1

Public telephone

network

Internet/Intranet or

online service

198.6.1.1

Analog POTS line

Figure 7 IP Address Translation

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 8. Any networking protocols such as IP, IPX and NetBEUI can be supported transparently through the tunnel. While the LAN Modem supports PPTP, it does not play an active role in creating or terminating a tunnel.

Figure 8 Connection to an Remote Private Network via an ISP

24 CHAPTER 2: 56K LAN MODEM FUNCTIONALITY DESCRIPTION

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

Setting Up the Server

Side of the Tunnel

Setting Up the Client

Side of the Tunnel

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 a 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 3Com’s NETBuilder, PathBuilder, Total Control Hub. An additional requirement is Microsoft’s 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.

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

Establishing a Tunnel via

the LAN Modem

■ Create a RAS phone book entry for the VPN

A RAS phone book entry is similar to other phone book entries with the exception of 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.

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 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.

Understanding VPNs and PPTP 25

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.

Refer to

http://www.remoteaccess.3com.com/support/docs/lanmodem for more

information. 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.

26 CHAPTER 2: 56K LAN MODEM FUNCTIONALITY DESCRIPTION

HARDWARE DESCRIPTION AND

NSTALLATION

This chapter provides an overview of the hardware description and installation of the 56K LAN Modem.

Package Contents The 56K LAN Modem package contents includes one of each:

■ OfﬁceConnect 56K LAN Modem

■ Power cable with an AC wall transformer

■ Analog telephone cable

■ 10BASE-T Ethernet cable

■ 3Com Companion Programs CD-ROM

■ OfﬁceConnect 56K LAN Modem Getting Started Guide

■ Rubber feet and stacking clips

Before You Install the 56K LAN Modem

To install, conﬁgure and use the 56K LAN Modem successfully, you must have the following:

■ An available analog POTS (Plain Old Telephone Service) connection with an

available RJ-11 outlet.

■ 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 (included in System 7.6 or later). Built-in Ethernet connectivity is provided through an Apple Ethernet port in all Power Macintosh computers.

■ A frames-capable, JavaScript-enabled Web browser. A Web browser is required to

access and conﬁgure your LAN Modem and to view the OfﬁceConnect 56K LAN Modem User Guide. You may use the customized browser provided on the 3Com Companion Programs CD-ROM, or you may use any frames-capable Web browser,

such as Netscape Navigator (3.0 and later) or Microsoft Internet Explorer (3.0 and later).

If you already have a version of Microsoft’s Internet Explorer W eb browser installed and would like to install a later version, you should ﬁrst uninstall the older version. During installation, you may be asked to replace the older ﬁles. It is recommended that you do so.

28 CHAPTER 3: HARDWARE DESCRIPTION AND INSTALLATION

■ TCP/IP software. 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.

Available storage space on your computer’s hard drive is not required because nothing is installed onto your computer as part of the 56K LAN Modem setup procedure. If you would like to copy any programs or documents from the included CD-ROMs, ensure that you have available hard disk space.

Front Panel LED Description

The front panel provides the following LEDs.

LAN STATUS

PWR CDAA OH

Alert

RD SD TX COLL 1 2 3 4

Figure 9 56K LAN Modem Front Panel

56K LAN Modem

3C886

3 Com

The functions of the front panel LEDs are described in Table 4. These front panel LEDs indicate proper operation and display 10BASE-T and analog port activity status.

Table 4 Front Panel LED Indicator Deﬁnitions

LED Color Description

Alert Amber Operational Status. Lit during power-on self-diagnostic test or

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

AA Green Auto Answer. Indicates the 56K LAN Modem’s answer mode.

CD Green Carrier Detect. Remains lit if the 56K LAN Modem receives a valid

RD Green Received Data. Flashes when the LAN Modem receives data from

SD Green Send Data. Flashes when the LAN Modem sends data to a remote

OH Green Off Hook. Remains lit when the modem has gone off hook. TX Green Ethernet Transmit Status. Flashes green when data is being

after pressing the reset button. Off indicates the unit has passed the diagnostic test and is working

properly. Flashes if one or more of the diagnostics have failed or after the

unit is placed in firmware download mode and is awaiting firmware upgrade.

unit.

Flashes during an incoming call. Remains lit for the duration of the call. Off when the LAN Modem originates a call.

data signal (carrier) from a remote modem (such as an ISP), indicating that data transmission is possible.

a remote site.

site.

transmitted to the Ethernet LAN from the 56K LAN Modem . Off indicates that no data is being transmitted to the Ethernet LAN

from the 56K LAN Modem.

Installing the 56K LAN Modem 29

Table 4 Front Panel LED Indicator Deﬁnitions (continued)

LED Color Description

Coll Amber Ethernet Collision Status. Flashes amber when some collisions

are taking place on the Ethernet LAN. Off indicates that no collisions are taking place on the Ethernet

LAN.

Ports 1-4 Green Ethernet LAN Port Status. On indicates that the unit detects the

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

Flashes when the LAN Modem receives data on the associated 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.

Back Panel Connector

Description

The back panel provides the following components.

10-18 VDC

0.8 A MAX

Power

Connector

Figure 10 56K LAN Modem Back Panel

RESET

LINE PHONE

Reset Button

Telephone

Line

Analog

Device

Four Ethernet

10BASE-T Connectors

312

LAN

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

■ Power: Connect the power module cable to this port.

■ Reset: Press this button to re-initialize the unit.

■ Line: Connect the provided RJ-11 analog line from the wall outlet to this port.

■ Phone: Connect an external analog device, such as a telephone or fax

machine, to this port.

■ Four 10BASE-T Ethernet Ports: Connect the computers on your LAN, or an

external hub, to these ports.

Installing the 56K LAN Modem

Before You Begin Before you begin, you will need the following in addition to the 56K LAN Modem:

This section describes how to do the following.

■ Install the analog cable

■ Connect to a 10BASE-T Ethernet LAN

■ Install analog equipment

■ Install the power cable

■ RJ-11 (6-pin) to RJ-11 (6-pin) telephone cable which was provided in your

modem package.

30 CHAPTER 3: HARDWARE DESCRIPTION AND INSTALLATION

■ 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. However, if you choose to use another cable it must be a straight-through 10BASE-T Ethernet cable. A crossover cable may not be used to connect the LAN Modem to a workstation.

■ Power adapter (you must use the power adapter provided in the package).

Installing the Analog

Cable

Connecting to a

10BASE-T Ethernet Port

To install the analog cable:

1 Connect one end of the RJ-11 analog cable to the RJ-11 analog port labeled Line

on the 56K LAN Modem’s back panel, as shown in Figure 11.

LINE PHONE

RESET

10-18 VDC

0.8 A MAX

Figure 11 Analog Cable Connection

2 Connect the other end of the RJ-11 analog cable to a POTS analog wall jack.

To connect a computer to the 56K LAN Modem, do the following.

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

the back of the 56K LAN Modem, as shown in Figure 12.

LINE PHONE

RESET

10-18 VDC

0.8 A MAX

Figure 12 10BASE-T Ethernet LAN Connection

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

CAUTION: Connect only one computer to the 56K LAN Modem for initial conﬁguration. Once conﬁguration is complete, you may connect the rest of the computers to the LAN.

+ 86 hidden pages