Us robotics Courier I-modem Getting Started Guide

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Courier™ I-modem®

Getting Started Guide

Final Draft

Based on part number 1.024.1153-00

1997 U.S. Robotics

8100 N. McCormick Blvd.

Skokie, IL 60076-2999 USA

The material contained in this manual is for information purposes only and is subject to change without notice.

No part of this document may be reproduced, transmitted, transcribed, or stored in a retrieval system in any form or by any means, mechanical, magnetic, electronic, optical, chemical, or otherwise without the written permission of U.S. Robotics.

U.S. Robotics, the U.S. Robotics logo, V.Everything, and Adaptive Speed Leveling are registered trademarks and Courier and x2 are trademarks of U.S. Robotics. Microsoft, MS-DOS, Windows, and Windows NT are registered trademarks of Microsoft Corporation. AppleTalk and Macintosh are trademarks of Apple Computer, Inc.

Any trademarks, trade names, service marks, or service names owned or registered by any other company and used in this manual are the property of their respective companies.

U.S. Robotics assumes no responsibility for errors or omissions in this manual. Nor does U.S. Robotics make any commitment to update the information contained herein.

1997 U.S. Robotics

8100 N. McCormick Blvd.

Skokie, IL 60076-2999 USA

Read this First

Installing Your Courier I-modem

To install your Go to

Internal modem Chapter 4, page 1 External modem into a PC Chapter 5, page 1 External modem to a Macintosh Chapter 5, page 1

Configuring Your Courier I-modem

To configure your Courier for Go to

Windows 95® Chapter 8, page 1 Macintosh® Chapter 9, page 1 Other operating systems Chapter 10, page 1

Using LEDs, Jumpers, and DIP Switches

To do this Go to

Locate jumpers Chapter 12, page 5 Modify jumper settings (internal Courier) Chapter 12, page 5 Locate DIP switches on the internal Courier Chapter 12, page 3 Modify DIP switch settings on the internal Courier Chapter 12, page 3 Locate DIP switches on the external Courier Chapter 12, page 1 Modify DIP switch settings on the external Courier Chapter 12, page 1 Understand the LEDs Chapter 13, page 1

Contents

Chapter 1 Introduction.............................................................................................1-1

How to Use this Guide............................................................................................... 1-1

Contacting U.S. Robotics ...........................................................................................1-1

I-modem Features ......................................................................................................1-2

Dial Security to Control Access to Your System..................................................... 1-2

Testing...................................................................................................................1-2

Flash ROM Upgradability.....................................................................................1-2

Plug and Play Support for Windows 95 ..................................................................1-2

Remote Configuration and Diagnostics..................................................................1-2

Terminal Adapter Features....................................................................................1-3

Integral V.Everything Modem Features ................................................................. 1-4

Chapter 2 The I-modem and ISDN..........................................................................2-1

Overview....................................................................................................................2-1

Internal I-modem....................................................................................................2-1

External I-modem................................................................................................... 2-1

External I-modem for Macintosh ............................................................................2-1

What is ISDN? ........................................................................................................... 2-2

Benefits of ISDN.....................................................................................................2-2

The ISDN Basic Rate Interface...............................................................................2-2

How Does the I-modem Fit In?...................................................................................2-4

U-Interface with Integrated NT-1............................................................................ 2-5

S/T Interface ...........................................................................................................2-5

Setting Up Your I-modem for ISDN ........................................................................... 2-6

How the I-modem Calls a Variety of Devices..............................................................2-6

Internet Access (TurboPPP)....................................................................................2-6

Universal Connect..................................................................................................2-7

V.110 Connections.................................................................................................. 2-7

Modem and Fax Calls............................................................................................. 2-7

Clear-Channel Synchronous Connections...............................................................2-7

Chapter 3 Ordering ISDN Service...........................................................................3-1

Overview...................................................................................................................3-1

The U.S. Robotics I-team....................................................................................... 3-1

Requesting ISDN Service ..........................................................................................3-2

Chapter 4 Installing Your Internal I-modem .........................................................4-1

Requirements .............................................................................................................4-1

Configuration Manager Requirements........................................................................4-1

Package Contents .......................................................................................................4-2

Important!..................................................................................................................4-3

Installing Your Internal I-modem............................................................................... 4-4

Step One: Configuring with Jumpers ......................................................................4-4

Step Two : Configuring with DIP Switches ..............................................................4-6

Step Three: Inserting the Modem............................................................................ 4-8

Step Four: Connecting the Cables ........................................................................4-10

Testing the Installation............................................................................................. 4-11

Chapter 5 Installing Your External I-modem......................................................... 5-1

What You Need..........................................................................................................5-1

Package Contents .......................................................................................................5-1

Installing Your External I-modem.............................................................................. 5-2

Step One: Connecting the Serial Cable...................................................................5-3

Step Two: Connecting the ISDN Cable ...................................................................5-4

Chapter 6 Using the Configuration Manager..........................................................6-1

Overview....................................................................................................................6-1

Configuration Manager..........................................................................................6-1

Configuring the I-modem ........................................................................................6-1

What You Should Know .............................................................................................6-1

Directory Numbers.................................................................................................6-1

Service Profile Identifiers....................................................................................... 6-2

Terminal Endpoint Identifier ..................................................................................6-2

Installing the Configuration Manager.........................................................................6-2

Configuring the I-modem...........................................................................................6-3

Testing.......................................................................................................................6-8

Special Considerations for AT&T 5ESS Custom ........................................................6-8

If You Have No SPIDS and Only One DN...............................................................6-9

If You Have One SPID and One DN...................................................................... 6-10

Chapter 7 Configuring With AT Commands........................................................... 7-1

Overview....................................................................................................................7-1

Configuring the I-modem ........................................................................................7-1

What You Should Know .............................................................................................7-1

Directory Numbers.................................................................................................7-1

Service Profile Identifiers....................................................................................... 7-1

Terminal Endpoint Identifier ..................................................................................7-1

Preparing to Send AT Commands ..............................................................................7-2

Configuring and Testing Your I-modem.....................................................................7-3

Step One: Configuring the I-modem........................................................................7-3

Step Two: Checking the Configuration....................................................................7-6

Step Three: Saving the Configuration.....................................................................7-6

Step Four: Testing the Configuration...................................................................... 7-7

Special Considerations for AT&T 5ESS Custom ........................................................7-8

If You Have No SPIDs and Only One DN................................................................7-9

If You Have One SPID and One DN...................................................................... 7-10

Chapter 8 Configuring Your Courier For Windows 95..........................................8-1

Overview....................................................................................................................8-1

What You Need..........................................................................................................8-1

Configuring Your Courier With Plug and Play ........................................................... 8-1

Files Needed By Your I-modem..................................................................................8-3

Installing the Latest I-modem Software ......................................................................8-4

Accessing Your Internet Service Provider ...................................................................8-4

Step One: Determine if Dial-Up Networking is Installed.........................................8-4

Step Two: Installing Dial-Up TCP/IP Support ........................................................8-7

Step Three: Setting Up a Connection to Your ISP...................................................8-8

Step Four: Customizing the TCP/IP Settings .........................................................8-11

Chapter 9 Configuring Your I-modem For Macintosh........................................... 9-1

Handshaking Cable ....................................................................................................9-1

System Configuration.................................................................................................9-1

Accessing the Internet ................................................................................................ 9-1

Configuring MacTCP .............................................................................................9-2

Installing MacPPP Dialer ......................................................................................9-2

Configuring ConfigPPP Dialer ...............................................................................9-3

Dialing With ConfigPPP......................................................................................... 9-3

Chapter 10 Configuring Your I-modem for Other Operating Systems............... 10-1

If You Are Using Windows 3.x................................................................................10-1

If You Are Using Windows NT 4.0.......................................................................... 10-2

What You Need....................................................................................................10-2

Configuring Your I-modem.................................................................................. 10-2

Installing the Latest I-modem Software................................................................10-2

If You Are Using MS-DOS......................................................................................10-3

If You Are Using OS/2............................................................................................10-4

If You Are Using UNIX, Linux, or AIX .................................................................. 10-5

Chapter 11 Configuring TurboPPP With AT Commands.....................................11-1

Overview................................................................................................................. 11-1

Point to Point Protocol (PPP) / ML-PPP...................................................................11-1

Determining TurboPPP Settings.......................................................................... 11-1

Setting PPP/ML-PPP Host and Originate Mode ..................................................11-2

Making Calls With ML-PPP ................................................................................ 11-2

Dynamic Data Bandwidth Allocation....................................................................... 11-4

Controlling Dynamic Bandwidth Allocation in ML-PPP...................................... 11-4

Setting When the Second Link Comes Up .............................................................11-5

Setting When the Second Link Comes Down......................................................... 11-5

Enabling the Tone When the Second Link Comes Up...........................................11-5

Using Compression in TurboPPP mode ...............................................................11-6

Chapter 12 Configuring Your I-modem With DIP Switches and Jumpers...........12-1

DIP Switches on the External I-modem ....................................................................12-1

Locating DIP Switches..........................................................................................12-1

Default DIP Switches (Model U) ...........................................................................12-1

Default DIP Switches (Model U, V.35)..................................................................12-2

Default DIP Switches (Model S/T) ........................................................................ 12-2

DIP Switches on the Internal I-modem .....................................................................12-3

Locating DIP Switches..........................................................................................12-3

Default DIP Switches............................................................................................12-3

Using DIP Switches to Configure Your I-modem...................................................12-4

Jumpers on the Internal I-modem .............................................................................12-4

Locating Jumpers .................................................................................................12-4

Changing Jumper Settings....................................................................................12-5

Setting Jumpers for a Specific COM Port .............................................................12-6

Setting Jumpers for a Specific IRQ....................................................................... 12-6

Chapter 13 Viewing LEDs......................................................................................13-1

Chapter 14 Using x2...............................................................................................14-1

Enhanced x2 Features..............................................................................................14-1

How to Tell if x2 is Enabled in Your I-modem ........................................................ 14-2

Obtaining x2 ...........................................................................................................14-2

How x2 Works.........................................................................................................14-3

Controlling x2.........................................................................................................14-3

x2 Server Mode ................................................................................................... 14-3

x2 Symmetric Mode (Host Mode).........................................................................14-3

Controlling Link Speeds with &N and &U ..............................................................14-3

Controlling Link Speeds ...................................................................................... 14-4

Limiting the Highest Possible Connect Speed ......................................................14-4

Limiting the Lowest Possible Connect Speed........................................................ 14-5

Limiting a Range of Possible Connect Speeds......................................................14-5

&N and &U Command Values............................................................................. 14-6

Troubleshooting x2 Client Connections...................................................................14-7

New x2 Result Codes ...............................................................................................14-8

Appendix A Other I-modem Features.....................................................................A-1

Data Over Voice.......................................................................................................A-1

Protocols Supported by Data Over Voice.............................................................. A-1

Configuring Data Over Voice............................................................................... A-1

Period Dial Modifier.................................................................................................A-2

PCSDL vs. XMODEM .............................................................................................A-2

230 kbps DTE Rate Under Windows®......................................................................A-2

Saving Money With Analog Calls.............................................................................A-3

Appendix B Technical Information.........................................................................B-1

Technical Specifications........................................................................................... B-1

Standards Compatibility....................................................................................... B-1

ISDN .................................................................................................................... B-1

Modulation........................................................................................................... B-2

Error Control, Data Compression, Testing, and Dialing ....................................... B-3

Fax....................................................................................................................... B-3

Additional Specifications...................................................................................... B-4

Ringer Equivalence .............................................................................................. B-5

Power Consumption .................................................................................................B-5

Serial Ports ............................................................................................................... B-5

The EIA-232 Interface.............................................................................................. B-6

Wiring a DB-25 to DB-9 Cable............................................................................. B-7

Minimum Requirements........................................................................................ B-7

For Macintosh Computers ........................................................................................B-8

Serial Ports (Macintosh modem)........................................................................... B-9

Appendix C The Serial Port....................................................................................C-1

Choosing a Serial Cable ............................................................................................C-1

Macintosh .................................................................................................................C-2

Appendix D Warranty .............................................................................................D-1

U.S. Robotics Access Corp. Limited Warranty...........................................................D-1

Terms of the Limited Warranty ..............................................................................D-1

What Is NOT Covered By the Limited Warranty .......................................................D-3

How To Access Your Warranty Services....................................................................D-4

Notices......................................................................................................................D-7

FCC Registration ..................................................................................................D-7

IC (Industry Canada) .............................................................................................D-8

UL Listed Accessory..............................................................................................D-9

Chapter 1

Introduction

How to Use this Guide

Use this Getting Started Guide to obtain the information you need to get your Courier™ I-modem® modem installed, configured, and running correctly.

For more information about advanced commands, view the I-modem Command Reference, which is on the Connections CD-ROM.

If you understand how ISDN works, you can skip directly to Chapter 3, Ordering ISDN.

Contacting U.S. Robotics

Please contact U.S. Robotics if you have any questions.

To do this Contact

Contact U.S. Robotics Technical Support 1.800.231.8770 Use the Fax-on-Demand service 1.800.762.6163 Download updated I-modem x2 code from

the U.S. Robotics Bulletin Board System

Download updated I-modem code http://totalservice.usr.com Visit the U.S. Robotics web site http://www.usr.com Visit U.S. Robotics on Compuserve GO USROBOTICS Visit U.S. Robotics on America Online Keyword: USROBOTICS

Introduction 1-1

847.982.5092 (analog)

847.734.8612 (V.120 ISDN)

I-modem Features

Dial Security to Control Access to Your System

The Courier’s Dial Security feature allows you to control access at a modem-to-modem level instead of using software that runs on the host computer. With Dial Security, you can prevent unauthorized access to a system through the use of password prompting and dial-back.

Testing

ITU-T V.54 loopback testing is available. The Courier can perform analog, digital, and remote digital loopback tests to determine if there are problems with the phone line, the remote device, or your Courier’s transmitter or receiver.

Flash ROM Upgradability

Courier modems are software-upgradable using XMODEM file transfers and U.S. Robotics Software Download (SDL) application, allowing you quick, easy access to updates of your Courier’s technology. The latest upgrades can be obtained on the U.S. Robotics web site or Bulletin Board System.

Plug and Play Support for Windows 95

The software for the external and internal Courier has been developed to support Plug and Play (as defined by the Plug and Play External and Internal COM Device Specification, Version 1.00). When you connect your Courier to a computer that uses a Plug and Play operating system, the computer automatically detects and configure itself to the support your Courier.

Remote Configuration and Diagnostics

You can remotely configure and test your Courier. If you are a network administrator supporting remote users, this feature can save you time and money.

Terminal Adapter Features

ISDN Terminal Adapter

The I-modem is an ISDN terminal adapter; it enables your computer to

1-2 Courier I-modem Getting Started Guide

communicate on the ISDN at speeds of up to 64 kbps.

Optional Built-in NT-1

The I-modems with Integrated NT-1 contain an on-board NT-1, sparing you the expense and extra cabling associated with an external NT-1.

Optional Analog Device Jack

The I-modem with Integrated NT-1 and Analog Device Jack allows you to plug in an analog telephone, fax machine, or modem, allowing analog devices to communicate over an ISDN B-channel. This applies to external units only.

TurboPPP

TurboPPP is U.S. Robotics’ unique combination of asynchronousto-synchronous PPP conversion, compression, multilink PPP (ML-PPP). You can use TurboPPP to access the Internet or remote local-area networks (LANs) at speeds of up to 128 kbps before compression and up to 512 kbps with compression.

Rate Adaptation

The I-modem’s support of the V.120 and V.110 protocols allows it to map slower-speed asynchronous data to the 64-kbps B-channel. The I-modem’s rate adaptation capability spans the range of 300 to 57600 bps.

Central Office Switch Compatibility

Works with AT&T 5ESS and Northern Telecom DMS-100 switches that run either their custom protocols or National ISDN-1, as well as with other manufacturer’s switches that use National ISDN-1 or National ISDN-2 call control signaling (ITU-T Q.931/I.451 call control signaling).

Introduction 1-3

Link Diagnostics

After each call, you can display a Link Diagnostics screen (ATI6) containing information about the last call, including the number of data characters transferred, line statistics, the call's rate, and the reason the call was disconnected.

Switched-56 Support

The I-modem can communicate to remote devices connected via Switched-56 circuits.

V.120 and V.110 Connections

V.120 and V.110 are standards for passing asynchronous data over ISDN B-channels, which are inherently synchronous. To make a connection using V.120 or V.110, devices at both ends of the connection must support V.120 or V.110.

Modem and Fax Calls

The I-modem emulates an analog fax/modem, allowing you to connect to remote analog modems and fax machines using 3.1 kHz audio format.

Voice Calls

If your I-modem has an Analog Device port, you can connect a standard, analog telephone and use the phone over your ISDN line. Be aware that the internal I-modem cannot provide ringing voltage through the Analog Device port, so equipment that autoanswers, such as a fax or answering machine, will not work correctly.

Integral V.Everything Modem Features

Supports Analog Fax/Modem Calls

The I-modem always makes and receives calls over ISDN. Since there is no guarantee that the device at the other end of the line is ISDN-capable, the I-modem can communicate with non-ISDN devices, such as analog modems and Group III fax.

1-4 Courier I-modem Getting Started Guide

x2 56-kbps Connectivity

If you have enabled x2, your Courier can connect at speeds up to 56 kbps. While line conditions may not always allow for 56 kbps connections, the new Courier software allows you to achieve the fastest analog speeds available.

Adaptive Speed Leveling to Adjust to Line Conditions

Adaptive Speed Leveling® (ASL) allows your Courier to monitor line conditions while connected, and fall back to the next lower speed if conditions are poor. Couriers also detect improved line conditions and shift upward to the next higher speed. The transmit and receive channels adapt independently, each detecting and adjusting to line conditions.

Calls to and from Modems and Fax Machines

When used with fax-capable communications software, your Courier auto-detects and responds to calls from modems and Group III fax machines using EIA-standard Class 1 or 2.0 fax software.

Data CompressionV.42 bis/MNP5

Data compression enables throughput of up to 230.4 kbps on analog connections. I-modems connecting under V.42 or HST error control use V.42bis compression. I-modems connecting under MNP error control use MNP Level 5 compression. Typically, files can be compressed from 2:1 to 4:1.

Error ControlV.42/MNP

Data integrity is ensured when the I-modem connects with remote devices that use the V.42 (LAPM), HST, or MNP error control protocols. Error control is available on analog calls at 1200 bps and above.

V.Everything

The Courier provides full support of the x2, V.34 standard, V.Fast Class, V.32 terbo, and many other modulation schemes, spanning the range of speeds between 300 bps and 56 kbps.

Introduction 1-5

1-6 Courier I-modem Getting Started Guide

Chapter 2

The I-modem and ISDN

The Courier I-modem with ISDN/V.Everything is an Integrated Services Digital Network (ISDN) terminal adapter that can perform all the functions of a Courier V.Everything fax/modem.

Overview

The I-modem is capable of exchanging data over the ISDN at speeds of up to 128 kbps with ISDN devices or up to 56 kbps with analog devices, before compression.

Internal I-modem

There are two versions of the internal I-modem:

• The ISDN U-Interface with an analog device jack (Model U)

• The ISDN S/T-Interface (Model S/T)

External I-modem

There are two versions of the external I-modem:

• The ISDN U-Interface with an analog device jack (Model U)

• The ISDN S/T-Interface (Model S/T)

External I-modem for Macintosh

There is one version of the I-modem for Macintosh. The Courier I-modem for Macintosh is the same as Model U (ISDN U-Interface with Analog Device Jack).

The I-modem and ISDN 2-1

What is ISDN?

RJ45 Jack

RJ11 Jack

RJ45 Connector

RJ11 Connector

Integrated Services Digital Network is an application of digital technology that provides end-to-end digital service over the public communications network. ISDN was designed to integrate the transmissions from a variety of devices, (computers, telephones, and fax machines) into one digital network.

Because ISDN was designed for transmitting digital information, it has many advantages over the analog telephone network. Digital transmission is more accurate and reliable, and that helps increase transmission speeds to up to 64 kbps per channel.

Benefits of ISDN

The benefits of ISDN include:

• Increased bandwidth

• Fewer errors during data transfer

• Quicker call setups and teardowns.

The ISDN Basic Rate Interface

Physical Appearance

The I-modem communicates over an ISDN Basic Rate Interface (BRI) line. You must order a BRI line from your local telephone company before you can use your I-modem. Chapter 2, Ordering ISDN Service, explains how to order ISDN and which services to request.

BRI works over the same wiring that is in place for your analog telephone lines. The difference is in the equipment you attach and the signaling used.

Figure 2.4 RJ45 and RJ11 Connectors and Jacks.

2-2 Courier I-modem Getting Started Guide

At your site, the BRI line takes the form of an RJ45 or RJ11 wall jack,

B-channel

(64 Kbps)

B-channel

(64 Kbps)

D-channel

(16 Kbps)

Physical View

Logical View

D-channelD-channel

which in ISDN is called the U interface. RJ45 connectors have eight pins and RJ11s have four or six pins. At the U-interface, you can plug an RJ11 connector into an RJ45 jack, and your line will work correctly.

The telephone company adds a line termination device at their end of the BRI that adapts the line for ISDN.

B-channels and D-channels

Though BRI signals are transmitted over an ordinary pair of wires, BRI typically contains three channels. The channels are created by complex signaling techniques.

BRI is composed of two 64-kbps B-channels and one 16-kbps D-channel:

This Does this

B-channels Carries (or “Bears”) data or voice traffic D-channel Sets up and tears down calls

The I-modem and ISDN 2-3

RJ45 Connector

Figure 2.5 ISDN BRI—Three Logical Channels Over One Pair of

Wires.

Required Components

BRI-line signals must be translated into signals your computer can understand. Several devices must be in place to perform the translation.

This Is a device

TE2 (Terminal Equipment 2)

TA (Terminal Adapter)

NT-1 (Network Termination

[Unit] -1

That does not have built-in ISDN capability. TE2s require Terminal Adapters (TAs), such as the I-modem, to communicate over the ISDN. Example: Computer.

That translates between non-ISDN signaling that TE2s provide (such as EIA-232) and the S/T-interface signaling that the NT-1 understands.

That ranslates between the short-distance signaling used at the S/T-interface and the longer-distance signaling used at the U-interface. NT-1s also convert from the two wires used for the phone line to the six or eight wires needed for the S/T bus.

How Does the I-modem Fit In?

The I-modem needs an NT-1 device to work with ISDN. If you currently use an NT-1 device, you can use the S/T-interface I-modem.

This version of I-modem Allows the I-modem to connect

U-Interface Integrated NT-1 Directly to the U-interface S/T-Interface To an external NT-1 device (you must

have an NT-1 device)

2-4 Courier I-modem Getting Started Guide

U-Interface with Integrated NT-1

Power

Figure 1–5 illustrates how the I-modems with Integrated NT-1 connect your computer to the ISDN.

BRI Line

I-modem

Figure 2.6 A Typical Installation of the I-modem

Once you’ve subscribed to ISDN service (see Chapter 2, Ordering ISDN Service, for much more detail), your local telephone company will install a

BRI line at your site. You install the I-modem in your computer and connect a cable between

the I-modem and the phone jack. Then run the I-modem Configuration Manager or send commands to change a few settings. Before long, you’ll be making calls on the ISDN.

S/T Interface

Figure 2.6 illustrates how the I-modem S/T connects your computer to the ISDN.

Note: Some NT-1s contain an integrated power supply.

NT-1

Supply

AC Power

ISDN

BRI

U + Power

S/T

I-modem

ISDN

Figure 2.7 A Typical Installation of the I-modem S/T.

The I-modem and ISDN 2-5

Setting Up Your I-modem for ISDN

You can get your ISDN service working by following these five easy steps:

Step One: Subscribe to ISDN service. Step Two: Your local telephone company will install a BRI line at your

site.

Step Three: Install the I-modem in your computer. Step Four: Purchase and install an NT-1 (if necessary) and connect the

cables. Step Five: Run the I-modem Configuration Manager and change a few

settings.

How the I-modem Calls a Variety of Devices

When you use the I-modem, all your calls go over one or both ISDN B-channels. However, you can set the I-modem to make different kinds of calls over the B-channel:

Internet Access (TurboPPP)

TurboPPP makes the most of your ISDN line in a way that’s transparent to your computer and the networking applications running on it. You can use TurboPPP to access the Internet or remote local-area networks (LANs) at speeds of up to 128 Kbps before compression and up to 512 Kbps with compression.

TurboPPP is U.S. Robotics’ unique combination of asynchronous-to-synchronous PPP conversion, compression, multilink PPP (MP-PPP), and PPP/MP-PPP spoofing.

Asynchronous-to-Synchronous PPP Conversion

Most Internet service providers that allow ISDN connections expect your data to arrive in synchronous Point-to-Point Protocol (PPP) format. Most computers, however, can’t deliver synchronous PPP through their serial ports.

To solve this problem, the I-modem has the ability to convert asynchronous PPP data to synchronous PPP. This capability allows you to use networking software that is intended for asynchronous PPP connections (such as Windows 95 Dial-Up Networking or NetManage Chameleon) to access the Internet or remote LANs.

2-6 Courier I-modem Getting Started Guide

Compression

The I-modem supports the leading de-facto standards for compression over ISDN: Stac LZS, Microsoft, and Ascend.

Multilink PPP (MP-PPP)

Multilink PPP support enables the I-modem to use both of the available B-channels simultaneously. The I-modem uses PPP/MP-PPP spoofing to mediate between applications running on your computer, which may not be aware of MP-PPP, and host computers that support MP-PPP. In effect, the I-modem tricks both ends of the connection, keeping them happy communicating the way they’re accustomed, while maximizing throughput.

Universal Connect

When the I-modem is set to Universal Connect, it autosenses V.120, V.110, or analog fax/modem connections. Use Universal Connect when calling ISDN or analog Bulletin Board Systems (BBSs), for example. For details, see Chapter 11, Handshaking, Error Control, Data Compression, and Throughput, in the I-modem Command Reference manual.

V.110 Connections

V.120 and V.110 are standards for passing asynchronous data over ISDN B-channels, which are inherently synchronous. To make a connection using V.120 or V.110, the device at the other end of the connection must also support V.120 or V.110. A typical application of V.120 is for BBSs.

Modem and Fax Calls

The I-modem emulates an analog fax/modem, allowing you to connect to remote analog modems and fax machines.

Clear-Channel Synchronous Connections

When you set the I-modem to make clear-channel synchronous connections, it sets up a 64 Kbps connection with a remote device, enabling you to exchange any kind of synchronous data. Common applications of clear-channel synchronous are videoconferencing and remote access to mini- or mainframe computers.

The I-modem and ISDN 2-7

2-8 Courier I-modem Getting Started Guide

Chapter 3

Ordering ISDN Service

This chapter gives you and your local telephone company all the information needed to set up the lines correctly.

Overview

To order ISDN service, contact your local telephone company, give them information about your I-modem, and record information that they give you, such as your new ISDN telephone numbers, called SPIDs.

If you decide that you would like assistance with the ordering process, call the U. S. Robotics I-team at (888) USR-ISDN.

The U.S. Robotics I-team

The I-team is a subset of U.S. Robotics’ Customer Support department that provides assistance with the ISDN ordering and configuring process. The I-team determines the availability and pricing of ISDN service in your area, installation costs, lead time for installation, and will coordinate the configuration of the telephone company’s equipment so your I-modem will work properly.

Ordering ISDN Service 3-1

Requesting ISDN Service

1 Call your local telephone company and request Bellcore Capability

Package S (listed in Bellcore SR-3840). If your telephone company does not recognize Bellcore capability

packages, request the following items:

• ISDN BRI service.

• Number of channels: 2B+D, with no packet-mode data on the D-

channel.

• Call type support:

This channel Supports

Data B-channel Circuit-Switched Voice and Data

(CSV/D)

Analog Device B-channel Circuit-Switched Voice and Data

(CSV/D)

• Dynamic TEI assignment.

• Multipoint bus configuration.

• No features or special services such as CACH EKTS, call

forwarding, or hunt groups.

• Terminal Type A.

• RJ45 jack (RJ11 is acceptable).

2 Specify your preferred long-distance provider. 3 Ask the telephone company which type of central-office switch your

ISDN line will terminate and which protocol the switch uses. Record the switch type and protocol here:

üü

Switch Protocol

AT&T 5ESS Custom

AT&T 5ESS National ISDN-1

Northern Telecom DMS-100 Custom (PVC 0 or 1)

Northern Telecom DMS-100 National ISDN-1 (PVC 2)

Siemens EWSD National ISDN-1

Other National ISDN-1

3-2 Courier I-modem Getting Started Guide

4 Obtain the following information from your local telephone company:

• 1 SPID (Service Profile Identifier) per B-channel.

• 1 DN (Directory Number) per B-channel.

• Call types supported on each B-channel.

• If the switch does not auto-assign TEIs (most do), then you need

one fixed TEI per B-channel.

For this Record the number here

SPID 1 SPID 2 DN 1 DN 2

5 If you have an internal I-modem, continue with Chapter 4, Installing

the Internal I-modem. If you have an external I-modem, continue with Chapter 5, Installing

the External I-modem.

Ordering ISDN Service 3-3

3-4 Courier I-modem Getting Started Guide

Installing Your

Internal I-modem

This chapter explains how to:

• Configure with jumpers

• Configure with DIP switches

• Insert the internal I-modem

• Connect cables to the internal I-modem

Important: Review Chapter 2, The I-modem and ISDN, and Chapter 3, Ordering ISDN Service, before installing the I-modem.

Requirements

You need the following to install your I-modem:

• IBM-compatible computer with a free interface card slot

• An ISDN Basic Rate Interface line

• Communications software

• An NT-1 and Power Supply (I-modem S/T only)

Chapter 4

Note: An NT-1 is a device that terminates the ISDN line and translates between the U-interface signaling from the telephone company and the S/T-interface signaling needed by ISDN terminal devices, such as the I-modem S/T. Only I-modem S/T’s require an external NT-1.

Configuration Manager Requirements

You need the following to run the U.S. Robotics I-modem Configuration Manager software:

• 386SX, or better, CPU.

• 8 MB, or more, RAM.

• DOS 5.0 or higher and Windows 3.1, or higher.

Installing the Internal I-modem 4-1

Package Contents

Your I-modem package contains the following items:

• The I-modem

• Telephone cable

• Quick Reference card

• Customer Support card

• This Getting Started manual

• I-modem Configuration Manager diskette.

• The Connections CD-ROM, which contains:

– I-modem Command Reference Guide – RapidComm communications software and manuals – Stampede Remote Office Gold software and manuals – Special offers – Updated I-modem INF file

4-2 Courier I-modem Getting Started Guide

Important!

The I-modem emulates a serial interface card with a 16550 UART. Like serial interface cards, it must be assigned a unique communications (COM) port number and a unique interrupt request (IRQ) number.

If you are using a computer with a Plug and Play compliant BIOS and operating system and you set the I-modem’s jumpers to Plug and Play (the default), your computer’s operating system will take care of the COM and IRQ settings for you.

Setting the COM port and IRQ yourself requires a detailed knowledge of the settings of the other adapter cards in your computer. If other adapter cards are set to use the same COM port or IRQ, conflicts may occur that could result in data loss or lockups.

First, determine whether your computer has a Plug and Play ISA bus. Check your computer’s documentation to be sure. Keep these points about Plug and Play in mind:

• Your computer’s operating system must support Plug and Play

(examples of those that do: OS/2 Warp, Windows 95, Windows NT), or your computer’s manufacturer must supply you with Plug and Play software.

• Your computer’s Basic Input/Output System (BIOS) must support

Plug and Play.

Installing the Internal I-modem 4-3

Installing Your Internal I-modem

To install your internal I-modem, do the following:

Step One: Configure your I-modem with jumpers (if necessary) Step Two: Configure your I-modem with DIPs (if necessary) Step Three: Insert your I-modem Step Four: Connect the cables

Step One: Configuring with Jumpers

Your I-modem comes configured for Plug and Play, which allows Windows 95 to automatically configure itself to work with the I-modem.

Jumpers

Figure 4.1 Jumpers

Default Jumper Settings

4-4 Courier I-modem Getting Started Guide

Figure 4.2 Default Jumper Settings

In addition to the shunt shown in Figure 4.2, the I-modem is shipped with two additional shunts. These shunts do not affect the configuration of your I-modem because they are attached to only one post; change the positions of these shunts only if you need to change hardware settings.

Notes:

• The S/T version has an additional set of jumpers.

• For most configurations, default settings will work. However, if your

environment has multiple ISDN devices or you are using an NT-1, see the I-modem Command Reference manual.

Windows 95 Users

If you are using Window 95, you should not need to change the Plug and Play jumper settings, because Windows 95 automatically detects and configures your Courier.

Other IBM-PC Compatible Operating Systems

If you are using an IBM-PC compatible operating system, you may need to change the jumper settings to a COM port or IRQ setting that is not already used by your system.

For information about setting jumpers for different COM ports and IRQ settings, see Chapter 12, Configuring Your Courier With DIP Switches and Jumpers.

Installing the Internal I-modem 4-5

Step Two : Configuring with DIP Switches

You will probably not need to change the DIP switch settings, but review this section to be sure.

The DIP (Dual Inline Package) switches are located on the bracket of the I-modem. See Figure 3-7 to learn how to set the switches.

DIP switches

Figure 4.3 Location of the DIP Switches.

4-6 Courier I-modem Getting Started Guide

OFF ON

No effect No effect

Ignore AT commands

Load &F0 template

settings on power-on or

reset

No effect No effect

Act on AT commands Load NVRAM settings

at power-on or reset

Figure 4.4 How to Set the DIP Switches.

For information about AT commands, refer to Chapter 2, Using the AT Command Set, in the I-modem Command Reference manual.

This DIP Switch

1 ON (Default) Loads the configuration that is stored

2 ON (Default) Acts on AT commands (smart mode)

3 OFF No effect 4 OFF No effect

Position Does this

in non-volatile memory (NVRAM)

OFF Loads the &F0 configuration that is

stored in read-only memory (ROM)

OFF Ignores AT commands (dumb mode)

When you power on your computer or reset the I-modem, the DIP switch settings override the settings you may have made previously using AT commands.

Note: The following AT commands are not changed by a power-on or reset and must be changed manually: &Cn, &Dn, En, Qn, Vn, S0=n, S14=n, and S67=n.

If you change the DIP switch settings while the I-modem is on, you can avoid powering your computer off to make the new settings take effect. Just send the I-modem the ATZ or the ATZ! command. (ATZ! is a “hard” reset, which is just like powering the I-modem off and then on. ATZ is a “soft” reset, which is like rebooting the I-modem and not removing power.)

Installing the Internal I-modem 4-7

Step Three: Inserting the Modem

Note: The illustrations in this section may not match the appearance of your computer. For more detail, refer to your computer’s user’s manual.

1 Turn off the computer’s power and unplug the computer’s power

cord. Ground yourself.

2 Remove the screws that hold on the computer’s cover and slide the

cover off.

3 Find an empty expansion slot that provides enough room to install

your Courier.

4 Remove the screw that holds on the slot cover and remove the slot

cover. Save the screw!

4-8 Courier I-modem Getting Started Guide

5 Insert your Courier into the slot and press down on the top edge of

your Courier until it is seated firmly.

6 Using the screw you saved in Step 4, secure your Courier in your

computer.

7 Replace the cover of your computer and tighten the screws.

You are now ready to connect the cables.

Installing the Internal I-modem 4-9

Step Four: Connecting the Cables

NT-1

I-modems with Integrated NT-1 Model U

1 Connect one end of the U-interface cable to the ISDN BRI jack and the

other end to the I-modem.

2 If your I-modem has an Analog Device port, connect an analog

device, such as a standard telephone, now. Be aware that the internal I-modem does not provide ringing voltage,

which may prevent normal operation of devices that auto answer (such as fax or answering machines).

I-modem Model S/T

1 Connect one end of the S/T-interface cable to an S/T port on your

NT-1 and the other end to the I-modem.

2 Install the NT-1 according to the steps listed in its documentation.

4-10 Courier I-modem Getting Started Guide

Testing the Installation

To test your Courier, use any communications software package, such as Windows Terminal, HyperTerminal, Procomm Plus, or RapidComm. HyperTerminal is used as an example. Every communications program is different; consult the documentation that came with your communications program for more information.

1 Run HyperTerminal. 2 Enter the name of your connection in Name and click OK.

Installing the Internal I-modem 4-11

3 Enter the phone number you want to dial in Phone number and click

OK. If you only want to test your modem, you may enter any

number.

4-12 Courier I-modem Getting Started Guide

4 Change any properties and:

To do this Click this button

Dial a number Dial Test without dialing a number Cancel

Installing the Internal I-modem 4-13

5 When the HyperTerminal terminal window appears, enter AT and hit

<enter>. If your modem is connected and configured properly, you

will see “OK” on the terminal screen.

You are now ready to configure your Courier modem.

4-14 Courier I-modem Getting Started Guide

Installing the Internal I-modem 4-15

Chapter 5

Installing Your

External I-modem

This chapter explains how to:

• Connect the serial cable

• Connect the ISDN cable

• Connect the power cord

What You Need

You need the following to install your Courier I-modem:

• Computer or terminal with a serial port (16650 UART recommended)

• ISDN Basic Rate Interface (BRI) line

Package Contents

Your Courier I-modem package contains the following items:

• Courier I-modem

• Power adapter

• Telephone cable

• Quick Reference card

• Customer Support card

• This Getting Started manual

• The Connections CD-ROM, which contains:

– Courier I-modem Command Reference Guide – RapidComm communications software and manuals – Stampede Remote Office Gold software and manuals – Special offers – An updated Courier I-modem INF file

Note about serial cables: You need a serial cable to connect your Courier to your computer. Because there are a variety of connector types that different computers require, and many users may already have an existing modem and serial cable, a serial cable is not provided with your Courier.

Installing the External Courier 5-1

These figures show the controls, displays, and connectors on your Courier I-modem and indicate where to find more information about each.

AA CD NS RD SD DTR MR RTS CTS SYNC ARQ/

B1 B2

FAX

withISDN/V.34

Figure 5.1 Front panel of the I-modem

Figure 5.2 Rear panel of the I-modem

Installing Your External I-modem

To install your external I-modem, do the following:

Step One: Connect the serial cable Step Two: Connect the ISDN cable Step Three: Connect the power cable

5-2 Courier I-modem Getting Started Guide

Step One: Connecting the Serial Cable

1 Look at the back of your computer for a port:

If you have Ports may be labeled this way

An IBM-compatible PC COM, RS-232, or with symbols such

as IOIOI, , or .

A Macintosh

(modem port) or (printer port)

Refer to your computer’s documentation to determine where the serial port is.

ISDNTelephone

S/TBus

I-modem

NT-1

This is a typical Model S/T configuration, which requires an external NT1 unit to connect to the ISDN wall jack. The I-modem Model U configuration is similar, but does not require an external NT-1. Instead, the I-modem Model U has an internal NT-1 and connects directly to the ISDN wall jack.

Installing the External Courier 5-3

Step Two: Connecting the ISDN Cable

1 After you have selected the correct cable, connect the male DB-25 end

of your serial cable to your Courier I-modem and the other end to a serial port on your computer.

If you have an IBM-compatible PC, connect the male DB-25 to your Courier I-modem and the other end to COM, RS-232, or with symbols such as IOIOI, , or .

If you have a Macintosh, connect the male DB-25 to your Courier Imodem and the other end to (modem port) or (printer port)

Note: Write down the number of the serial port to which you connect your Courier I-modem. If your serial ports are lettered instead of numbered, A is COM1 and B is COM2. If you cannot find a serial port, consult the documentation that came with your computer.

2 Connect one end of the phone cable to the wall jack and the other end

to your Courier I-modem port labeled U.

3 If you have Model U and a telephone that you’d like to connect to

your Courier I-modem, plug its cable into your Courier port labeled PHONE.

4 Plug one end of the power adapter into your Courier I-modem and

the other end to a standard AC power outlet.

5 Switch your computer and modem power on.

You are now ready to configure your Courier I-modem.

5-4 Courier I-modem Getting Started Guide

Chapter 6

Using the Configuration Manager

This chapter explains how to configure and test the I-modem using the Configuration Manager software.

If the computer to which you’ve connected the I-modem cannot run Windows applications, follow the steps in Chapter 7, Configuring With AT Commands.

Overview

Configuration Manager

The I-modem Configuration Manager is designed to help you make the ISDN settings to your I-modem and test whether you have a working connection with the central-office switch.

Configuring the I-modem

Before you can make any calls, you need to configure the I-modem to work on your ISDN line. If you haven’t ordered an ISDN line, see Chapter 3, Ordering ISDN Service.

Install and run the Windows Configuration Manager software shipped with the I-modem. The Configuration Manager runs on Windows 3.1, Windows 95, Windows NT, and Macintosh.

What You Should Know

Directory Numbers

Directory Numbers (DNs) take the form of ordinary seven- or ten-digit telephone numbers. Be sure to leave off the area code from your DN.

Using the Configuration Manager 6-1

Service Profile Identifiers

Service Profile Identifiers (SPIDs) tell the telephone company about any special services and features to which you've subscribed. SPIDs can be up to 20 digits long.

Terminal Endpoint Identifier

The TEI is a one or two digit number that permanently identify a your connection with the central office switch.

Installing the Configuration Manager

1 Make sure the I-modem is attached to your computer and powered

on.

2 Power-on your computer and start Windows. 3 Insert the Courier I-modem Configuration Manager diskette in drive

A (or drive B).

4 Windows 3.x: From the Program Manager group’s menu bar, select

File, and then Run... Windows 95: Click Start, and then Run…

5 Enter a:\setup (or b:\setup, depending on the drive into which you

inserted the diskette). The installation program will start.

6 When you’re prompted, enter the drive and directory where you

want the Configuration Manager installed. The default is c:\i-modem.

The installation program installs the software and creates an I-modem Configuration Manager program group and icons.

6-2 Courier I-modem Getting Started Guide

The following window appears when installation is complete.

7 Eject the diskette from the drive.

Configuring the I-modem

1 Start the I-modem Configuration Manager by clicking the ISDN

Program icon: The following window appears:

2 Select the COM Port to which the I-modem is connected and then

select Open COM Port. Once you communicate successfully with the I-modem, the first

Using the Configuration Manager 6-3

window disappears and the following window appears: (If you cannot communicate with the I-modem, you may have a COM

port or IRQ conflict. Refer to Chapter 15, Troubleshooting, in the I-modem Command Reference manual.)

14 15 16

1 Data Channel Call Type

Choose one of the following call types for the Data Bchannel. Your choice applies for both incoming and outgoing calls.

This call type Allows these types of calls

Automatic Service Choice V.120, then analog fax/modem V.120 Rate Adaptation V.120 only V.110 Rate Adaptation V.110 only Analog Modem Analog fax/modem only Clear Channel Clear-channel synchronous Internet Access TurboPPP, then analog fax/modem

2 Data Channel Service Profile ID

Enter the SPID (up to 20 digits) for the Data B-channel.

3 Data Channel Directory Number

6-4 Courier I-modem Getting Started Guide

Enter the DN for the Data B-channel. Do not include your

area code.

4 Data Channel Terminal Endpoint ID

Typically, ISDN service providers assign TEIs automatically. If you were given a fixed TEI, type it in this blank. If not, leave 00.

5 Analog Device Channel Dialing Method

If you select The I-modem dials

Standard Analog Like a standard phone. All Digits At Once Like a cellular phone (press # to send

dialed number).

6 Analog Device Channel Call Type

Choose one of the following call types for the Analog Device B-channel. Your choice applies to outgoing calls only.

If you want to use Select this call type

Higher quality audio 3.1 kHz audio or speech (Analog

Modem or Fax)

Lower quality audio Speech

7 Analog Device Channel Service Profile ID

Enter the SPID (up to 20 digits) for the Analog Device Bchannel.

8 Analog Device Channel Directory Number

Enter the DN for the Analog Device B-channel. Do not include your area code.

Using the Configuration Manager 6-5

9 Analog Device Channel Terminal Endpoint ID

Typically, ISDN service providers assign TEIs automatically. If you were given a fixed TEI, type it in this blank. If not, leave 00.

10 Switch Protocol Type

Choose the switch protocol used by your ISDN service provider.

11 Incoming Modem/Fax Call Routing

This section is active only if you select AT&T 5ESS

Custom as your switch protocol type. Explained in Special Considerations for AT&T 5ESS Custom later in this chapter.

12 Bus Configuration

This field is active only if you select AT&T 5ESS Custom as your switch protocol type. Explained in Special Considerations for AT&T 5ESS Custom later in this chapter.

13 Audio Port Volume

Controls the volume of the sound from the receiver of a

device that’s attached to the Analog Device port. 0 is quietest and 9 is loudest. 4 is the default and is recommended.

14 Save Button

Check all the settings to make sure they’re correct, and

then click Save. The following message appears:

15 Test Button

Select Test to reset the I-modem and begin a 90-second period of attempts to connect to your central office switch. Watch the Switch Connectivity Test window.

6-6 Courier I-modem Getting Started Guide

Physical Interface indicates whether there is a good physical connection between the I-modem and the central-office switch.

If the Physical Interface is The I-modem has made

Inactive No connection. Active A good connection.

The Data Link Layer can be active only when the Physical Interface is active. An active Data Link Layer indicates that the I-modem is ready to make or receive calls.

If the Data Link Layer is

Inactive Is not ready to make or receive calls. Active Is ready to make or receive calls. Active (Incorrect

SPID)

16 Exit Button

Then the I-modem

Cannot make or receive calls because the central office switch does not recognize the SPID set in the I-modem.

When you see the Switch Test Completed message, you’re ready to make and receive calls! Select Exit to close the Configuration Manager.

Using the Configuration Manager 6-7

Testing

1 Start your communications software package. Use a terminal

emulation program, such as HyperTerminal.

2 Change the COM port and IRQ settings in your communications

software to match the I-modem’s setup.

3 Make a test data call.

a Put your communications software in Terminal Mode. b Call the U.S. Robotics BBS. Type the following:

ATDT18477348612 <Enter>

Or, in the 847 area code:

ATDT7348612 <Enter>

Note: When you make ISDN calls, you won’t hear dialing or training tones when the call is being made.

You should see one of the following messages:

CONNECT 56000/ARQ/DIGITAL/V120 CONNECT 64000/ARQ/DIGITAL/V120

If you don’t see one of these messages, refer to Chapter 15, Troubleshooting, in the I-modem Command Reference manual.

4 I-modems with Analog Device Jack: Make a test voice call.

When the network connects the call, the B1 or B2 LED should flash. If you have set up your analog device B-channel to use All Digits At

Once (en-bloc) dialing, you must press the star (*) key after you dial the number in order to send it.

If you have trouble making analog calls, refer to Chapter 15, Troubleshooting, in the I-modem Command Reference manual.

Note: Any device attached to the Analog Device port cannot use the line unless the I-modem is powered on.

Special Considerations for AT&T 5ESS Custom

If your central-office switch is an AT&T 5ESS that runs the Custom

6-8 Courier I-modem Getting Started Guide

protocol, you can use fewer than two SPIDs/DNs, although this is not recommended. Lines with fewer than two SPIDs/DNs prevent your making two analog-based calls at one time.

For example, with fewer than two SPIDs/DNs, you can make a digital call (such as V.120 or synchronous PPP) and a voice call at the same time, but not a fax/modem and a voice call simultaneously.

SPIDs DNs Bus Configuration

0 1 Point-to-Point 1 1 Multipoint 2 2 Multipoint

If You Have No SPIDS and Only One DN

Make these modifications when entering your line configuration.

2 Data Channel Service Profile ID

Leave this field blank.

3 Data Channel Directory Number

Enter your DN. Do not include your area code.

7 Analog Device Channel Service Profile ID

Leave this field blank.

8 Analog Device Channel Directory Number

Enter your DN again. Do not include your area code.

10 Switch Protocol Type

Select AT&T 5ESS Custom.

Using the Configuration Manager 6-9

11 Incoming Modem/Fax Call Routing

Select one of the following:

To use The I-modem routes incoming analog calls

Analog Device Port

Data Port To the Data Port (handled by the I-modem).

12 Bus Configuration

To the Analog Device port (handled by the device attached to the Analog Device port).

Select Point-to-Point.

If You Have One SPID and One DN

Make these modifications when entering your line configuration.

2 Data Channel Service Profile ID

Enter your SPID (up to 20 digits).

3 Data Channel Directory Number

Enter your DN. Do not include your area code.

7 Analog Device Channel Service Profile ID

Enter your SPID (up to 20 digits). This field should be blank if you have only on SPID.

8 Analog Device Channel Directory Number

Enter your DN. Do not include your area code.

10 Switch Protocol Type

Select AT&T 5ESS Custom.

11 Incoming Modem/Fax Call Routing

Select one of the following:

To use The I-modem routes incoming calls

To Analog Device Port

To Data Port To the Data Port (handled by the I-modem).

12 Bus Configuration

To the Analog Device port (handled by the device attached to the Analog Device port).

Select Multipoint.

6-10 Courier I-modem Getting Started Guide

Configuring With

AT Commands

This chapter explains how to configure and test the I-modem using AT commands and terminal software.

Overview

Configuring the I-modem

Before you can make any calls, you need to configure the I-modem to work on your ISDN line. If you haven’t ordered an ISDN line, see Chapter 3, Ordering ISDN Service.

Run your communications software in Terminal mode and then use your software to send the I-modem AT commands.

What You Should Know

Chapter 7

Directory Numbers

Directory Numbers (DNs) take the form of ordinary seven- or ten-digit telephone numbers. Be sure to leave off the area code from your DN.

Service Profile Identifiers

Service Profile Identifiers (SPIDs) tell the telephone company about any special services and features to which you've subscribed. SPIDs can be up to 20 digits long.

Terminal Endpoint Identifier

The TEI is a one or two digit number that permanently identify a your connection with the central office switch.

Configuring with AT commands 7-1

Preparing to Send AT Commands

1 Get the information from your ISDN service provider that contains

your ISDN phone numbers and central-office switch type.

2 Start your computer and your communications software. Use a

terminal emulation software package, such as HyperTerminal.

3 Put your communications software into Terminal mode.

When your communications software is in Terminal mode, the commands you type go directly through the serial port to the I-modem. Refer to the manual for your communications software to determine how to change to Terminal mode.

4 Set your communications software to use the COM port to which the

I-modem is connected, as well as 8 data bits, no parity, and 1 stop bit.

5 Send the following command (all commands surrounded by angle

brackets, like <Enter>, indicate key presses):

AT <Enter>

If you installed the I-modem and set your communications software correctly, it sends the following response:

Note: If you don’t get an OK response, refer to Chapter 15,

Troubleshooting, in the I-modem Command Reference.

7-2 Courier I-modem Getting Started Guide

Configuring and Testing Your I-modem

Before you can use your Courier, you must perform the following steps.

Step One: Configure the I-modem Step Two: Check the I-modem’s settings Step Three: Save the settings Step Four: Test the I-modem

Step One: Configuring the I-modem

1 Look over the information you received from your ISDN service

provider to obtain your central-office switch and protocol type.

This switch type Supports this protocol type

Northern Telecom DMS-100 National ISDN-1 (PVC 2)

Custom (PVC 0 or 1)

AT&T 5ESS National ISDN-1

∗

Other (for example, Siemens EWSD)

Custom

National ISDN-1

The command is AT*W=n

To set this switch protocol type Use this command

AT&T 5ESS Custom* AT*W=0 Northern Telecom DMS-100 AT*W=1 National ISDN-1 AT*W=2 National ISDN-2 AT*W=3

∗

If your switch protocol is AT&T 5ESS Custom, see Special Considerations for AT&T 5ESS Custom on

page 5-7.

Configuring with AT commands 7-3

2 Set the appropriate bus configuration.

To set Use this command

Point to point AT*M=0 Multipoint AT*M=1

3 Set up the ANALOG DEVICE B-channel.

a Set the Service Profile Identifier (SPID).

The command is AT*S1=n Example: AT*S1=84755511110111 <Enter>

b Set the Directory Number (DN).

The command is AT*P1=n Example: AT*P1=5551111

c Set the Terminal Endpoint Identifier (TEI), if you were

assigned one. If not, continue with step d. The default setting is 0, or dynamic TEI assignment. The

TEI permanently identifies your link with the central office switch.

The command is AT*T1=n

If your TEI Use this command

Is dynamic AT*T1=00 Is fixed AT*T1=n, where n is a number from 1 to 63.

7-4 Courier I-modem Getting Started Guide

d Set the Call Type.

Note: The call type that you choose will apply to outgoing calls only.

The command is AT*V1=n

To set this call type Use this command

3.1 kHz audio (for modem, fax, or voice calls)

Speech only AT*V1=1

4 Set up the DATA B-channel.

a Set the Service Profile Identifier (SPID).

The command is AT*S2=n Example: AT*S2=84755511120111

b Set the Directory Number (DN).

The command is AT*P2=n Example: AT*P2=5551112

c Set the Terminal Endpoint Identifier (TEI), if you were

assigned one. If not, continue with step d. The default setting is 0, or dynamic TEI assignment. The command is AT*T2=n

If your TEI Use this command Is dynamic AT*T2=00

AT*V1=0

Is fixed AT*T2=n, where n is a number from 1

to 63.

Configuring with AT commands 7-5

d Set the Call Type.

Note: The call type you choose will apply to both incoming and outgoing calls.

The command is AT*V2=n

To set this call rype Use this command

Automatic service choice (Universal Connect)

V.120 rate adaption calls only AT*V2=1 V.110 rate adaption calls only AT*V2=2 Modem or fax emulation only AT*V2=3 Clear-channel synchronous calls

only Internet access mode (default) AT*V2=5

You are done configuring your I-modem.

Step Two: Checking the Configuration

Send ATI12 <Enter>, and check that the settings you made are correct.

Step Three: Saving the Configuration

Reset the I-modem by sending ATZ! <Enter> or power off the modem and power it on again.

Sending ATZ is not sufficient! Send ATZ! <Enter> Your settings will not take effect until the I-modem undergoes this type of reset.

AT*V2=0

AT*V2=4

Note: If your phone company requires compliance with Bellcore

Special Report NWT 1953, which introduces a random delay of 45 to 65 seconds when bringing up your line, you can set the I-modem to comply by sending ATS67.4=1 <Enter>. To disable compliance, send ATS67.4=0 <Enter>.

7-6 Courier I-modem Getting Started Guide

Step Four: Testing the Configuration

1 After you reset your I-modem (in Step Three) watch the I-modem’s

LED status indicators. AA, DTR, MR, RTS, and CTS should be lit green, and NS should blink yellow rapidly.

Watch the NS LED closely. It should follow this pattern:

Step The NS LED Means this

Fast blink (8 per

second), Yellow Slow blink (1 per

second), Green Green solid Ready to make or receive calls

Searching for U interface (I-modem Model 1 and 2 only)

Searching for S/T interface

Physical connection active

These are error conditions and suggested solutions:

If NS LED does this This may be the problem

Red blink (1 per second) Incorrect SPID. Send ATI12 <Enter>

and re-check your SPID and DN settings.

Red solid No physical connection. Make sure

that the U-interface cable is plugged into the I-modem.

Configuring with AT commands 7-7

2 Make a test data call.

Call the U.S. Robotics BBS. Type the following:

ATDT18477348612 <Enter>

Or, in the 847 area code:

ATDT7348612 <Enter>

Note: When you make ISDN calls, you won’t hear dialing or training tones when the call is being made. This is normal.

You should see one of the following messages:

CONNECT 56000/ARQ/DIGITAL/V120 CONNECT 64000/ARQ/DIGITAL/V120

Note: If you don’t see one of these codes, refer to Chapter 15,

Troubleshooting, in the I-modem Command Reference.

Special Considerations for AT&T 5ESS Custom

If your central-office switch is an AT&T 5ESS that runs the Custom protocol, you can use fewer than two SPIDs/DNs, although this is not recommended. Lines with fewer than two SPIDs/DNs prevent your making two analog-based calls at one time.

For example, with fewer than two SPIDs/DNs, you can make a digital call (such as V.120 or synchronous PPP) and a voice call at the same time, but not a fax/modem and a voice call simultaneously.

SPIDs DNs Bus Configuration

0 1 Point-to-Point 1 1 Multipoint 2 2 Multipoint

7-8 Courier I-modem Getting Started Guide

If You Have No SPIDs and Only One DN

Make these modifications when entering your line configuration.

1 Switch protocol type. Set to AT&T 5ESS Custom: enter AT*W=0 2 Bus configuration. Set to Point-to-Point: enter AT*M=0 3aData channel SPID. Leave blank: enter AT*S2= and press <Enter>. 3bData channel DN. Enter your DN (do not include your area code.

For example, AT*P2=5551111

4aAnalog Device channel SPID. Leave blank: enter AT*S1= and press

<Enter>.

4bAnalog Device channel DN. Enter your DN: for example,

AT*P1=5551111

Also, decide whether incoming analog fax/modem calls are routed to the Analog Device port (to be handled by the voice device attached to the Analog Device port) or to the Data Port (to be handled by the I-modem).

To route these calls to Use this command

Analog Device Port Data Port

Configuring with AT commands 7-9

ATS67.3=0 ATS67.3=1

If You Have One SPID and One DN

Make these modifications when entering your line configuration.

1 Switch protocol type. Set to AT&T 5ESS Custom: type AT*W=0

<Enter>.

2 Bus configuration. Set to Multipoint: type AT*M=1 <Enter>. 3aData channel SPID. Enter your SPID (up to 20 digits): for example,

type AT*S2=84755511110111 <Enter>.

3bData channel DN. Enter your DN (do not include your area code.

For example, AT*P2=5551111 <Enter>.

4aAnalog Device channel SPID. Leave blank: enter AT*S1= and press

<Enter>..

4bAnalog Device channel DN. Enter your DN: for example,

AT*P1=5551111 <Enter>. Also, decide whether incoming analog fax/modem calls are routed to

the Analog Device port (to be handled by the device attached to the Analog Device port) or to the Data Port (to be handled by the Imodem).

To route calls to the Use this command

Analog Device Port Data Port

7-10 Courier I-modem Getting Started Guide

ATS67.3=0 ATS67.3=1

Chapter 8

Configuring Your Courier

For Windows 95

This chapter explains how to:

• Configure your I-modem for use with Plug and Play

• Obtain and install the latest I-modem files

• Configure Dial-Up Networking to access your ISP

Overview

The first time you start Windows 95 after you’ve installed your Courier, Windows 95 auto-detects your Courier. Since Windows 95 supports Plug and Play, most installations are trouble-free.

Note for external Courier users: You must power on your I-modem before you start Windows 95, or Windows 95 will not recognize your I-modem.

What You Need

You need Windows 95 with Dial-Up Networking installed to configure your I-modem for Windows 95.

Configuring Your Courier With Plug and Play

Plug and Play mode allows Windows 95 to automatically detect your Imodem and determine which modem configuration file (called an INF file) to use.

Note for internal Courier users: If you do not want to use the Plug and Play mode of your operating system, you must manually change the jumpers on the modem to the desired COM port/ IRQ settings. For information about setting jumpers for different COM ports and IRQ settings, see Chapter 12, Configuring Your Courier With DIP Switches and Jumpers.

Windows 95 8-1

Follow the steps below to install I-modem INF file for Windows 95:

1 Power on your computer and start Windows 95. Your computer

detects new hardware and displays the following window:

2 Select Driver from disk provided by hardware manufacturer and

click OK to install the INF file that is provided on the root directory (D:\ or the correct path of your CD-ROM) of the Connections CDROM.

8-2 Courier I-modem Getting Started Guide

3 When the following window appears, insert your Connections CD-

ROM, change the default drive (A:\) in “Copy Manufacturer’s files from” to D:\ (or the correct path of your CD-ROM) and click OK to install the INF file.

Windows 95 displays the following window asking you to choose your I-modem type from the list:

4 Select the Courier I-modem with ISDN & V.34 PC (Internal) or

Courier I-modem with ISDN & V.34 (External) from the list and click OK.

Your I-modem is now ready to use!

Windows 95 8-3

Files Needed By Your I-modem

For your I-modem to work most efficiently, U.S. Robotics recommends that you use the latest version of the following two files from the U.S. Robotics web site (http://totalservice.usr.com) or ISDN (847.734.8612) or analog (847.982.5092) BBS.

This file Does this

The I-modem software

The INF file Helps your computer work more effectively

Contains software that contains new feature updates

with your I-modem

8-4 Courier I-modem Getting Started Guide

Installing the Latest I-modem Software

See your I-modem Command Reference Manual for information about upgrading your Courier’s software.

Accessing Your Internet Service Provider

This section explains how to set up your I-modem to access the Internet using Windows 95 Dial-Up Networking. You can also use Dial-Up Networking to access Internet Service Providers (ISPs) or remote LANs. To access your ISP or a remote LAN, you must do the following:

Step One: Determine if Dial-Up Networking is installed. Step Two: Install Dial-Up TCP/IP support. Step Three: Set up a connection to your ISP. Step Four: Customize TCP/IP settings (if necessary).

Step One: Determine if Dial-Up Networking is Installed

1 Click Start | Settings | Control Panel. 2 On the Control Panel, double-click on Network to

display the Network Window.

Windows 95 8-5

If Dial-Up Networking Do this

Is listed Go to the section “Installing TCP/IP

Support” to install Dial-Up Networking.

Is not listed Go to Step 3.

3 Return to the Control Panel and double-click on

Add/Remove Programs to open the Add/Remove Programs Properties window:

8-6 Courier I-modem Getting Started Guide

4 Click Windows Setup tab.

Windows 95 8-7

5 Double-click on Communications to display the Communications

window:

6 Click on Dial-Up Networking to check the box. 7 Click OK | OK. 8 Insert your Windows 95 Setup diskette or CD-ROM when you are

prompted, and Windows 95 installs Dial-Up Networking.

8-8 Courier I-modem Getting Started Guide

Step Two: Installing Dial-Up TCP/IP Support

1 Click Start | Settings | Control Panel. 2 On the Control Panel, double-click on the

Network icon to display the following window:

Determine if the TCP/IP Dial-Up Adapter is installed:

IF TCP/IP -> Dial-Up Adapter

Is not listed Click Add… | Protocol | Microsoft | TCP/IP

Windows 95 8-9

Do this

| OK. Insert your Windows 95 Setup diskette or CD-

ROM when you are prompted, and Windows 95 installs TCP/IP protocol

support.

Is listed Read the section “Customize the TCP/IP

Settings”

8-10 Courier I-modem Getting Started Guide

Step Three: Setting Up a Connection to Your ISP

1 Click Start | Programs | Accessories | Dial-Up Networking. 2 Double-click Make New Connection. 3 Select the correct Courier modem, if not already

selected.

4 Type a name for the connection and click Next .

Windows 95 8-11

5 Type a phone number for the connection and click Next .

6 You should see a message indicating that a new connection was

created successfully.

8-12 Courier I-modem Getting Started Guide

7 Click Finish. 8 On the Dial-Up Networking window, move your cursor to the new

icon you have just created and click the right mouse button. Select

Properties on the menu to display the following window:

8 On the My Connection window, click Server Type…, and deselect the

following:

• Log on to Network

• NetBEUI

• IPX/SPX Compatible

9 Click OK, and OK.

If your ISP Do this

Gives you specific IP or server addresses

Does not give you specific IP or server addresses

Windows 95 8-13

Go to Step Four: Customizing TCP/IP Settings

Double-click on the icon you just created to dial your ISP.

Step Four: Customizing the TCP/IP Settings

Depending on the ISP you use, you may need to customize the TCP/IP settings. Contact your ISP for specific information, such as IP address, or domain name servers (DNS).

1 Click My Computer and double-click Dial-Up Networking icon to

display all the connections you can customize.

2 Right-click the icon you created and select

Properties to display the My Connection

window.

8-14 Courier I-modem Getting Started Guide

3 On the My Connection window, click Server Type to display the

TCP/IP Settings window.

4 Specify an IP address, if needed:

If your ISP Do this

Gives you a specific IP address Click Specify an IP address

and enter the IP address provided by your ISP

Does not give you a specific IP address

Windows 95 8-15

Click Server assigned IP address

5 After you specify an IP Address, specify server assigned server

addresses, if needed:

If your ISP Do this

Gives you specific server addresses

Does not give you specific server addresses

Click Specify name server addresses and enter the server address(es) provided by your ISP

Click Server assigned server

address

6 Double-click your New Connection icon to connect!

8-16 Courier I-modem Getting Started Guide

Configuring Your

I-modem For Macintosh

This chapter explains how to configure your I-modem for use with Macintosh computers.

Handshaking Cable

Use a hardware handshaking cable to connect your I-modem to the Macintosh.

System Configuration

Also, if you aren’t using AppleTalk® Remote Access (ARA), set AppleTalk to Inactive (in Chooser).

The modem initialization string should be AT&F1&D0. For instructions about how to set up your Macintosh communications

software package, visit the U.S. Robotics Totalservice web site at http://totalservice.usr.com.

Chapter 9

Accessing the Internet

Accessing the Internet through an ISP requires the following software:

• MacTCP or Open Transport (TCP/IP from the Control Panels menu), which has probably already been installed on your Macintosh

• SLIP or PPP dialing software

Note: You can find public domain PPP dialers (such as MacPPP and FreePPP) on the Internet.

Macintosh 9-1

Configuring MacTCP

1 Open the MacTCP control panel. 2 Click PPP and More… 3 In Obtain Address group box, click Server. 4 In Domain Name Server Information, enter the domain name and IP

address for one or more domain name servers.

Note: If you don’t have domain name server information, contact your ISP.

When you’re finished configuring MacTCP, restart your Macintosh.

Installing MacPPP Dialer

When you install MacPPP for the first time, a PPP icon appears in the MacPPP folder. Put the PPP icon in the Extensions Folder, in the System Folder, and restart your Macintosh.

9-2 Courier I-modem Getting Started Guide

Configuring ConfigPPP Dialer

1 ConfigPPP is your PPP dialer. 2 Open ConfigPPP and click New... 3 Enter your Port Name and click OK. 4 Click Config… and set your Port Speed (the fastest speed for MacPPP

is 57.6 kbps), phone number, and modem initialization string.

5 Click Authentication… and enter the user name and password your

ISP assigned you.

6 Click Done.

Dialing With ConfigPPP

In Config PPP, click Open. Config PPP dials your ISP and establishes your PPP connection.

Macintosh 9-3

9-4 Courier I-modem Getting Started Guide

Chapter 10

Configuring Your I-modem

for Other Operating Systems

This chapter explains how to configure your I-modem for:

• Windows 3.x

• Windows NT

• MS-DOS

• OS/2

• UNIX, Linux, or AIX

If You Are Using Windows 3.x

Windows 3.x comes with a built-in communications software package, Windows Terminal. You can use Windows Terminal to test your I-modem or you can install the communications software package that is included on the Connections CD-ROM.

Because Windows Terminal only supports speeds up to 19200 bps, it is recommended that you use a third-party communications software package.

For instructions about how to set up your Windows 3.x communications software package, visit the U.S. Robotics Totalservice web site at http://totalservice.usr.com.

Other Operating Systems 10-1

If You Are Using Windows NT 4.0

What You Need

You need Windows NT with Remote Access Service (RAS) installed to configure your I-modem for Windows NT.

Configuring Your I-modem

To obtain and install the I-modem INF file for Windows NT, follow the same steps as Windows 95 users.

Installing the Latest I-modem Software

After you obtain the latest I-modem INF file, copy it to the C:\WINNT\INF subdirectory.

For more information about Windows NT, see the Windows NT documentation or visit the U.S. Robotics Totalservice web site at http://totalservice.usr.com.

10-2 Courier I-modem Getting Started Guide

If You Are Using MS-DOS

Because there is no communications software built in to MS-DOS, you must install and run a third-party communications software package to operate your I-modem.

RapidComm, which is included on the Connections CD-ROM, contains MS-DOS and Windows 3.1 versions of RapidComm.

You must choose the COM port to which your I-modem is attached in whatever communications software package you are using.

For instructions about how to set up your MS-DOS communications software package, see the software documentation or visit the U.S. Robotics Totalservice web site at http://totalservice.usr.com.

For Internal Couriers Only

You must choose the COM port, IRQ, and the I/O address within the communications software that you use. These are the standard I/O address and IRQ settings for each COM port:

COM Port I/O Address IRQ

COM1 03F8 IRQ4 COM2 02F8 IRQ3 COM3 03E8 IRQ4 COM4 02E8 IRQ3

Other Operating Systems 10-3

If You Are Using OS/2

Replace the standard OS/2 serial port drivers COM.SYS and VCOM.SYS with SIO.SYS and VSIO.SYS. You can get these enhanced drivers from the U.S. Robotics web site.

For instructions about how to set up your OS/2 communications software package, visit the U.S. Robotics Totalservice web site at http://totalservice.usr.com.

For Internal Couriers Only

These are the standard I/O address and IRQ settings for each COM port:

COM Port I/O Address IRQ

COM1 03F8 IRQ4 COM2 02F8 IRQ3 COM3 03E8 IRQ4 COM4 02E8 IRQ3

Nonstandard COM/IRQ settings are done by adding switches (command line parameters) to the COM.SYS (or SIO.SYS) line in CONFIG.SYS.

For example, to select COM3 and IRQ5, enter the following command line:

\OS2\BOOT\COM.SYS /i5/c3

10-4 Courier I-modem Getting Started Guide

If You Are Using UNIX, Linux, or AIX

Linux has a built-in communications software package called minicom. You can obtain minicom on the U.S. Robotics FTP site (ftp.usr.com) in the usr/bin directory.

For instructions about how to set up your UNIX®, Linux, or AIX communications software package, visit the U.S. Robotics Totalservice web site at http://totalservice.usr.com.

These are the standard port names and settings:

Outgoing Calls Incoming Calls Port IRQ I/O Address

/dev/cua0 /dev/ttyS0 COM1 4 03F8 /dev/cua1 /dev/ttyS1 COM2 3 02F8 /dev/cua2 /dev/ttyS2 COM3 4 03E8 /dev/cua3 /dev/ttyS3 COM4 3 02E8

Use the setserial command to tell Linux about any nonstandard COM/IRQ combinations that you may have set using your Courier’s jumpers. Setserial also selects serial port speed and I/O port address.

Other Operating Systems 10-5

10-6 Courier I-modem Getting Started Guide

Configuring TurboPPP

With AT Commands

This chapter explains how to control TurboPPP with AT commands.

Overview

TurboPPP allows your I-modem to use both B-Channels to send and receive data over the ISDN.

TurboPPP includes the following features:

This feature Allows the I-modem to

Chapter 11

PPP/ML-PPP (Multilink PPP)

Dynamic Data Bandwidth Allocation (DBA)

Accept PPP/ML-PPP calls

Save money by only using the second B-channel when it is need for data transfers, and then dropping the second B-channel when it is not needed

Point to Point Protocol (PPP) / ML-PPP

Your Courier I-modem now supports Originate and Host Mode PPP/ ML-PPP. Host Mode ML-PPP allows you to set the I-modem to accept ML-PPP calls. Originate Mode allows PPP/ML-PPP calls to be made from the I-modem.

Determining TurboPPP Settings

To do this Use this command

Obtain an overview of TurboPPP settings

ATI16

Configuring with AT commands 11-1

Setting PPP/ML-PPP Host and Originate Mode

Use the following *P settings to control PPP/ ML-PPP:

To do this Use this

setting

Set all PPP-related

*P=0 *V2=5, S68.2=0, S68.3=0,

default values

Set Asynchronous to

*P=1 S68.2=1

Or these settings

S68.6=0, S69.1=0, *D1=2, *D2=24 *D3=90, *D4=44, *K=1

Synchronous PPP Set Single Link

*P=2 S68.2=0, S68.3=1

TurboPPP Set ML-PPP

*P=3 S68.2=0, S68.3=0 (default)

Note: Before you can use this feature you must enable PPP/ ML-PPP using *V2=5.

Making Calls With ML-PPP

You can make ML-PPP calls with any PPP dialer.

Making an Outgoing ML-PPP Call

When making an outgoing ML-PPP call, enter the number of the host. If the phone number for two calls is different, you must enter both of them. They must be separated by an ‘&’ as shown below. If only one phone number is given, the same number will be dialed for both calls.

Making an Incoming ML-PPP Call to Your I-modem

When someone attempts to call your I-modem using ML-PPP, they must call the Data number first and the Voice number second.

See the following figures for an example of phone numbers with and without ML-PPP using Windows 95. These rules apply when using terminal programs with other operating systems.

11-2 Courier I-modem Getting Started Guide

Regular Connection Without ML-PPP

Connection With ML- PPP

Configuring with AT commands 11-3

Dynamic Data Bandwidth Allocation

Dynamic Data Bandwidth Allocation is a cost savings feature that helps you save money by only using the second B-channel when it is need for data transfers, and then dropping the second B-channel when it is not needed. Dynamic Bandwidth Allocation determines the need for the second B-channel by measuring the amount of data sent or received during a set period of time.

Dynamic Data Bandwidth Allocation settings (*D0, *D1, *D2, *D3, and *D4) determine under which conditions the second link should be brought up or down.

If you enter a value in TurboPPP does this

*D3 that is more than the time set in *D1 Brings up the second link *D4 that is less than the time set in *D2 Brings down the second link

Important: Dynamic Bandwidth Allocation is set on by default. To turn off Dynamic Bandwidth Allocation, use *D0=1.

Controlling Dynamic Bandwidth Allocation in ML-PPP

Use the following *D0 settings to control Dynamic Bandwidth Allocation:

To do this Use this setting Or this setting

Enable Dynamic Bandwidth Allocation in ML-PPP (default).

Disable Dynamic Bandwidth Allocation in ML-PPP

*D0=0

*D0=1

S68.6=0

S68.6=1

Use the following settings to control the period of time your I-modem samples the throughput in order to determine if the second link needs to be brought up or down:

To set the period of time your I-modem samples througput to determine

If a second link should be brought up

If a second link should be brought down

Use this setting Example

*D1=n, where n equals 1-255 five second units

*D2=n, where n equals 1 -255 five second units

*D1=2 (ten seconds)

*D2=10 (50 seconds)

11-4 Courier I-modem Getting Started Guide

Setting When the Second Link Comes Up

Use the following *D3 setting to determine when the I-modem should bring up a second link:

To do this Use this setting Example

Determine when the second link should be brought up, based on the level of utilization of the existing link

*D3=n, where n equals 1 -100%

*D3=90

(90%)

Setting When the Second Link Comes Down

Use the following *D4 setting to determine when the I-modem should bring down a second link:

To do this Use this setting Example

Determine when the second link should be brought down, based on the level of utilization of the existing link

*D4=n, where n equals 1-100%

*D4=44

Enabling the Tone When the Second Link Comes Up

Use the following *T settings to enable the tone when the I-modem brings up a second link:

To do this Use this setting Or this setting

Enable tone when second link is brought up (default)

*T=0 S69.1=0

Disable tone when second link is brought up

*T=1 S69.1=1

Configuring with AT commands 11-5

Using Compression in TurboPPP mode

Courier I-modem supports the following three types of compression modes in TurboPPP.

Pass-through Compression

Pass-through compression allows the terminal applications running on each PC on both ends of the connection to perform compression. Using this form of compression, the Courier I-modem does not perform compression.

Pass-through compression allows for maximum compression by eliminating the serial port bottleneck.

Auto Mode Compression

Auto Mode Compression allows the I-modem to negotiate compression if your application cannot negotiate compression. This is the default.

Turbo Mode Compression

Turbo Mode Compression allows the I-modem to negotiate compression with the remote host and disable compression between the I-modem and your application.

Setting Modes of Compression

Use the following *K settings to use compression in TurboPPP mode:

Use this mode of compression Use this setting

Pass-through Mode Auto Mode (Default) Turbo Mode

U.S. Robotics recommends that you enable the compression in your application software and keep compression set to &K1 (default).

Note: Under Auto Mode Compression (&K1), the I-modem allows your application to negotiate compression. If you have enabled compression in your application and the application successfully negotiates compression, then the I-modem switches to Transparent Mode compression and allows your application do data compression.

11-6 Courier I-modem Getting Started Guide

*K0 *K1 *K2

I-modem supports a 230 kbps DTE rate using ML-PPP.

Configuring with AT commands 11-7

11-8 Courier I-modem Getting Started Guide

Us robotics Courier I-modem Getting Started Guide

Specifications and Main Features

Frequently Asked Questions

User Manual