Chapter 2. Setting Up an ISDN Connection

Several steps are involved in setting up your workstation so it can communicate across an ISDN connection. It may take several weeks to set up the connection, depending on how quickly you can obtain the appropriate hardware and services from your local telephone company.

This chapter guides you through all the steps in the process. Read “Prerequisites for Using ISDN” first; if your situation does not satisfy those prerequisites, you will not be able to use an ISDN connection.

This chapter contains the following sections:

Prerequisites for Using ISDN

An ISDN connection is basically a network connection between two systems that transfers information over a high-speed telephone line rather than an Ethernet connection. If you wish to establish an ISDN connection, you must order the PCI-BRI ISDN card from Silicon Graphics (unless you are using an Indy workstation, in which case the hardware and software are part of the system). See the manual or flier that comes with your hardware for installation instructions.

To use ISDN, your situation and location must have these characteristics:

  • The remote system that you plan to connect to must already be set up to use ISDN; that is, it must already have ISDN hardware, software, and services in place. See also “Requirements for Remote ISDN Systems.”

  • Your system must be located near a telephone switching office that offers ISDN services, typically, within two or three miles (three or five kilometers) of such an office. See also “Ordering ISDN Services and Hardware.”

  • You need a telephone jack. If you have a standard jack that supports only one telephone number, your local telephone company can split the jack so it can support both the existing telephone number and a new, dedicated ISDN telephone number.

    If you do not have a jack, or you already have two telephone numbers on your existing jack, you can have the telephone company or an electrician install a new telephone wire and jack.

Ordering ISDN Services and Hardware

If your situation meets all the prerequisites listed in “Prerequisites for Using ISDN,” you are ready to order your services and hardware.

Ordering ISDN Services

Contact your telephone company and go through the questions and ordering requests in this section with a person qualified to set up ISDN services.

  1. Make sure your telephone company can provide Basic Rate Interface (BRI) ISDN services to your location. Typically, your system must be within two or three miles (three or five kilometers) of a telephone switching office that offers ISDN.

  2. Tell the telephone company that you want a BRI (not PRI) ISDN connection.

  3. When they ask about the B channels and D channel, say this:

    • You want circuit-switched data on both B channels. You do not want X.25 (also called packet-switched data); you do not want voice or any of the additional voice-related services (such as call hold, consultation hold, 3-way conference, and so on).

    • You want standard signaling on the D channel. You do not want X.25 (also called packet-switched data) or any additional services.

  4. U.S. customers only: Ask what type of switch hardware and switch software your telephone company uses. It will be one of four types:

    • 5ESS hardware running 5ESS custom software

    • 5ESS hardware running 5ESS National ISDN 1 software (also called NI1 software)

    • DMS100 hardware running BCS level 31, 32, 33, or 34 (Protocol Version 1) software

    • DMS100 hardware running BCS level 35 or higher (Protocol Version 2) software (also called DMS100 National ISDN 1 or NI1 software).

    The telephone company representative may know the hardware type or the software type but not both. If this is the case, ask the representative to research both the software and the hardware types.

  5. U.S. customers only: The telephone company will request information about your workstation. They may refer to the workstation as an ISDN terminal, Customer Premise Equipment (CPE), or a Terminal Adapter (TA). The information the telephone company needs depends on the type of switch software the telephone company uses.


    Note: Some telephone companies do not require the detail listed here; they automatically assume you have a type D terminal, which provides you with a superset of the services you need.

    The list below shows the switch software type and the appropriate information.

    5ESS custom 

    Terminal type: E
    Number of call appearances: None
    Display: No
    Idle call appearances: None
    Autohold: No
    One touch: No
    No. of circuit-switched data channels: 2
    EKTS: No
    Data line class: point-to-point


    Note: If you plan to connect more than one device to the ISDN line, your data line class is point-to-multipoint, or just multipoint.


    5ESS NI1 

    Terminal Type: A
    Number of call appearances: None
    Display: No
    Idle call appearances: None
    Autohold: No
    One touch: No
    No. of circuit-switched data channels: 2
    EKTS: No

    DMS100 BCS level 31, 32, 33, or 34 (Protocol Version 1) 


    Dynamic TEI: Yes
    Maximum number of keys: 3
    Ringing indicator: No
    EKTS: No

    DMS100 NI1 

    Dynamic TEI: Yes
    Maximum number of keys: 3
    Ringing indicator: No
    EKTS: No

  6. U.S. customers only: The telephone company may ask these additional questions:

    • Does the system have automatic or fixed Terminal End Identifier (TEI)? It has automatic TEI.

    • Is the system functional or stimulus? (This applies only if the telephone company's hardware is DMS100.) It is functional.

  7. German customers only: Ask the telephone company whether their switch runs 1TR6 or NET3 software.

  8. Ask for your ISDN telephone number(s) and Service Profile Identifier (SPID) number(s). The information the telephone company provides depends on the type of switch software it uses. The list below shows the switch software type and the information you need.

    • 5ESS custom: One telephone number. The telephone company may provide you with a corresponding SPID number; you need to know the SPID number only if you are setting up a point-to-multipoint connection rather than the standard point-to-point connection.

    • 5ESS NI1, DMS100 BCS level 31, 32, 33, or 34 (Protocol Version 1), or DMS100 NI1: Two telephone numbers and two corresponding SPID numbers.

    • NTT, 1TR6, or NET3 (also known as Euro-ISDN or DSS-1): One telephone number.

    Write down your switch software type, the telephone number(s), and, if necessary, the SPID number(s).

  9. This should be enough information for the telephone company to set up your ISDN service. If they need more information about your system, see “Technical Background” for more-detailed technical information.

    Before you end your conversation with the telephone company, ask whether you're speaking with a person who can do the following:

    • Order additional hardware from the telephone company or from a vendor that the telephone company recommends. See “Ordering ISDN Hardware.”

    • Set up long-distance calling service for the line if you plan to connect to systems that are located outside your area code.

Ordering ISDN Hardware

If you live in Japan or Germany, after you've ordered your ISDN services as described in “Ordering ISDN Services,” your local telephone company automatically ships you the additional ISDN hardware you need to connect to a telephone jack.

If you live in the United States, you must explicitly order additional ISDN hardware from your local telephone company or from a vendor that the telephone company recommends. When you order the hardware, make sure it includes all the appropriate cables. The list below itemizes the equipment and cabling you need to connect your workstation to a standard telephone jack.

  • An NT1 device: This small device (about the size of a standard VHS videotape) converts the standard 2- or 4-wire telephone jack signal (also called a U interface) to an 8-wire ISDN signal (called an S/T interface).

  • A power supply unit for the NT1 device: This is roughly the same size as the NT1 device; it supplies power from a standard AC outlet to the NT1 device.

  • A power cable: This connects the power supply unit to the AC outlet. Typically this cable is already connected to the power supply unit.

  • A short, straight-through RJ-45 cable: This connects the NT1 device to the power supply unit. It is usually included with the power supply unit.

  • A long, straight-through RJ-11 cable: This is the standard cable that connects a telephone to a standard jack. With an ISDN connection, it connects the power supply or NT1 device to the jack.

  • A 5- to 7-foot straight-through RJ-45 cable: This 8-wire high-speed cable with RJ-45 connectors on both ends connects the NT1 device to your workstation.


    Note: This is not the same type of cable that is used for a 10-BaseT connection.

    If your telephone company does not supply this cable, you can order it from a number of vendors, including Silicon Graphics and Inmac.

When your hardware arrives and your ISDN services are ready (see “Ordering ISDN Services”), go to “Setting Up ISDN Hardware.”

Setting Up ISDN Hardware

A wide variety of NT1 devices is available in different countries. This section shows a sample setup that consists of a workstation, a Northern Telecom Meridian NT1 device, a Northern Telecom Meridian power supply unit for the NT1, and a telephone wall jack.

Set up the connection as follows, regardless of the type of NT1 device you have:

  1. The wall jack supplies a standard RJ-11 telephone jack; this is called the U interface.

  2. Connect one end of a standard 4-wire RJ-11 cable to the wall jack (U interface) and connect the other end to the RJ-11 port on the power supply unit (if you have one) or the NT1 device. This port should be labeled with a U.

    If you have both a power supply unit and an NT1 device, connect the RJ-11 cable to the wall jack and the U port on the power supply, then connect the short RJ-45 cable to the jacks labeled with a U and a solid and dashed line on both the power supply unit and the NT1 device. Connect the power cable on the power supply unit to a standard AC outlet.

  3. Connect one end of a straight-through 8-wire RJ-45 cable to either of the RJ-45 ports on the NT1 that are labeled S/T. Connect the other end of this cable to the ISDN port on the workstation.

See Figure 2-1 for a setup that includes both an NT1 device and a power supply unit.

Figure 2-1. ISDN connection between a workstation, an NT1 device, and a power supply unit.


When all the hardware is set up, see “Setting Up ISDN Software.”

Setting Up ISDN Software

You need root privileges to set up ISDN software. It involves these three steps:

  1. Install the UUCP, PPP, and ISDN software. This online book is part of the ISDN software, so UUCP, PPP, and ISDN are already installed.

  2. Configure system files for basic ISDN use; see “Setting Up Basic ISDN.”

  3. Build a list of remote ISDN systems and networks that you want to access; see “Building a List of Remote ISDN Connections.”

Once your ISDN software is set up and you are able to access other systems, you can provide your ISDN information to them so they can access your system; see “Letting Other ISDN Systems Access Your System.”

Using the Interactive Guides

The following sections describe how to use the interactive guides, available in the System Manager to set up ISDN. To access the guides, follow these steps:

  1. Choose System Manager from the System Toolchest.

  2. In the System Manager, select the Network and Connectivity category.

    A list of guides appears in the right-hand column of the window.

  3. To open a guide, click its name in the right-hand column.

The guides display text that describes how to proceed and allows you to enter the appropriate information.


Note: To perform many of the operations described below, you need to know the root password or be logged into the root account.


Setting Up Basic ISDN

Before you use this task, refer to “Setting Up ISDN Hardware.”

  1. After the ISDN line is installed, have available the following information from the telephone company:

    1. The type of switch software; for example, DMS100 or NT1.

    2. The SPID number or numbers. Depending on the type of switch software, you may not be given an SPID number or you may be given one or more SPID numbers.

    For 5ESS point-to-multipoint, you need one SPID number, which you obtained in “Ordering ISDN Services.” DMS100 BCS level 31, 32, 33, or 34 (Protocol Version 1) and DMS100 NI1 have 2 SPID numbers.

You also need a hostname and an IP address for your system. This information is available from the network administrator of the network to which you plan to connect.

To set up basic ISDN, follow these steps:

  1. Select Network and Connectivity in the left-hand column of the System Manager window (see “Using the Interactive Guides” above). In the right-hand column, click Set Up ISDN; then follow the steps in the interactive guide to complete the configuration. When you are finished, ISDN is up and running.

If you haven't assigned a hostname and IP address to your system or haven't turned on basic networking, perform this step now.

If you do not have an Ethernet cable connected to your system (if ISDN is the only type of networking you're using), perform Step 3.

  1. Select the Network and Connectivity category in the left-hand column of the System Manager window (see “Using the Interactive Guides” above). In the right-hand column, click Start Up Networking; then follow the steps in the guide to complete the setup.

  2. Select the Network and Connectivity category in the left-hand column of the System Manager window (see “Using the Interactive Guides” above). In the right-hand column, click Modify Network Settings. On the page headed Set the State of Ethernet, in the guide, select Disable; then go to the end of the guide and click OK.

The basic ISDN software is set up. Go to “Building a List of Remote ISDN Connections.”

Building a List of Remote ISDN Connections

Once your basic ISDN software is set up (see “Setting Up Basic ISDN”), you can build a list of the remote locations (systems and networks) that you want to communicate with using your ISDN connection.

You can set up to an outgoing or an incoming ISDN connection:

    • To call out to a computer at a remote location, use the Add an Outgoing PPP Connection guide.

    • To allow an incoming call from a computer at a remote location, use the Add an Incoming PPP Connection guide.

  1. Select the Network and Connectivity category in the left-hand column of the System Manager window (see “Using the Interactive Guides” above). If you want to call a remote site, select Add an Outgoing PPP Connection, in the right-hand column, and complete the steps in the guide. If you want to specify which remote sites can call you, select Add an Incoming PPP Connection and follow the steps.


Note: If you do not specify an incoming PPP connection, any remote site can call you.

Go to “Turning On and Testing the ISDN Connection.”

Turning On and Testing the ISDN Connection

Once you have set up the basic ISDN software (see “Setting Up Basic ISDN”), you can test the connection.

  1. Select Network and Connectivity in the left-hand column of the System Manager window (see “Using the Interactive Guides” above). In the right-hand column, select ISDN Manager.

  2. Click the Confidence Test button to start the test. If there is a problem, one or more error messages appear, in which case, see “Troubleshooting the ISDN Connection.” If there are no error messages, ISDN is working properly.

  3. Select the Network and Connectivity category in the left-hand column of the System Manager window (see “Using the Interactive Guides” above). In the right-hand column select PPP Manager; then double-click the icon of the outgoing connection that you want to establish. A status panel appears.

  4. Click the Open Connection button and check the status (“The connection is CLOSED” or “The connection is OPEN”).

  5. To verify whether the remote system has accepted your password and is running PPP, in the right-hand column of the ISDN Manager window, click the Line Status button. A window appears that displays the activity of your ISDN lines.

  6. Choose Open Unix Shell from the Desktop Toolchest.

  7. In the shell window that appears, type

    /usr/etc/ping <hostname>

    For example, if the hostname is mars, type

    /usr/etc/ping mars

    After ten seconds, press <Ctrl-c>.

    If you see a message that reports 0% packet loss, the connection is working. Go to the next step.

    If the message reports a large percentage of packet loss, the connection or network routing is not working. See “Troubleshooting the ISDN Connection.”

  8. Close the connection by clicking the Close Connection button.

  9. Customize your ISDN setup or start using the connection now.

Adding Remote Systems to the /etc/hosts File

The /etc/hosts file contains a list of all the remote systems that your system can access once the ISDN connection is open. Each line of the file contains an IP address and a hostname. You can use the Modify Network Settings guide to add a new system (host) to your etc/hosts file. Follow these steps:

  1. Select the Network and Connectivity category in the left-hand column of the System Manager window (see “Using the Interactive Guides” above). In the right-hand column, click Modify Networking Settings.

  2. Then go to the page titled Add an Entry to the Host File and enter the hostname and IP address of the remote system.

    For example, enter the hostname saturn.accompany.com and the IP address 192.0.2.9.

  3. Go to the last page of the guide and click OK to add the system to your etc/hosts file.

Letting Other ISDN Systems Access Your System

To let other ISDN systems access your system, do the following:

  1. Select the Network and Connectivity category in the left-hand column of the System Manager window (see “Using the Interactive Guides” above); then click Add an Incoming PPP Connection and follow the steps.


Note: If you do not use Add an Incoming PPP Connection, any remote site can call you.

If you are concerned with system security, see “Using a System Security Scheme.”

Troubleshooting the ISDN Connection

The troubleshooting information in this section covers many common error conditions. If you need more-detailed information, see the ppp man page.

This section shows you how to use a shell window and issue direct PPP commands to troubleshoot efficiently.

Troubleshooting Guidelines

  1. Make sure that all physical connections are solid and that the NT1 device is powered on. If you had to solidify a connection or power on the NT1 device, restart the system and try using ISDN again.

  2. Open the ISDN Manager.

    Select the Network and Connectivity category in the left-hand column of the System Manager window (see “Using the Interactive Guides” above). In the right-hand column, click ISDN Manager.

  3. In the ISDN Manager window, click the Confidence Test button to start the test.

    If there is a problem, one or more error messages appear. If the notifier reports a problem, follow the instructions that the confidence test gives you for correcting the problem.

  4. To see startup status messages for testing purposes, type

    ppp -r <connection name> -d

Error Messages During the Initial Setup

This section lists various error messages that you may encounter during your initial setup of ISDN. Typically you'll see these messages after trying to connect to a remote system for the first time by typing ppp -r <connection name> -d. The message generally appears in your shell window, although some of them appear in the /var/adm/SYSLOG file.

To obtain information on error or status messages, follow these steps:

  1. Open another shell window and in the new window type

    isdnstat

    When you place the call in the next step, isdnstat reports on the progress of the call. For more details, see the isdnstat man page. To stop isdnstat from running, type:

    q

  2. In the shell window in which you're logged in as root, place the call and request additional information from PPP by typing

    ppp -r <connection name> -d

    You do this in the shell window because the debug messages are displayed in the shell window as

    ppp [xxx] <connection name>:<error message>

    The window in which you started isdnstat shows the progress of ISDN, and the window in which you typed the ppp command gives you information about PPP.

    You can request more information by adding additional -d flags to the ppp command line, but this will introduce security problems. See the ppp man page for details.

This section covers these error conditions:

Unknown Switchtype

Unknown switchtype “<switchtype>

This message indicates a problem in ISDN's configuration.

  1. To verify that the switch software type is correct, select Network and Connectivity in the left-hand column of the System Manager window (see “Using the Interactive Guides” above). In the right-hand column, select Set Up ISDN.

Login Failed

ppp[348] <connection name>: fatal error “LOGIN FAILED” on try #2

ppp[348] <connection name>: giving up for now

This message may appear immediately (within three seconds) after you try to make the connection, or may appear after several more seconds.

If you see the message immediately, your system cannot access the ISDN line through your NT1 device, typically because the NT1 is powered off or the telephone line is unplugged. Check that all connections are solid and that the NT1 is powered on, then follow these steps:

  1. Open a shell window, log in as root, then type

    /etc/init.d/isdnd stop

    /etc/killall ppp

    /etc/init.d/isdnd start

  2. Wait 30 seconds, then try again, requesting more error or status information, by typing

    ppp -r <connection name> -d

  3. If you see the same error message, there may be a problem with the telephone company's switching software. Contact the telephone company to report the problem.

If you see the Login Failed message after several seconds, there is a different problem; for example, the remote system may be down or its ISDN connection may already be in use. For more information, follow these steps:

  1. Open another shell window and in the new window type

    isdnstat

    When you place the call in the next step, isdnstat reports on the progress of the call. For more details, see the isdnstat man page. To stop isdnstat from running, type

    q

  2. In the shell window in which you're logged in as root, place the call and request additional information from PPP by typing

    ppp -r <connection name> -d

    The window in which you started isdnstat shows the progress of ISDN, and the window in which you typed the ppp command gives you information about PPP.

System Not in Systems File

ppp[434] <connection name>: fatal error “SYSTEM NOT IN Systems FILE” on try #2

ppp[348] <connection name>: giving up for now

The above message means that there is a problem with the outgoing connection that you added.

Use the Modify an Outgoing PPP Connection guide to correct any errors with the connection.

  1. Select the Network and Connectivity category in the left-hand column of the System Manager window (see “Using the Interactive Guides” above) and click ISDN Manager.

  2. Select the connection that isn't working and click the Modify button.

    The Modify an Outgoing PPP Connection guide appears.

  3. Check your settings (see “Building a List of Remote ISDN Connections”). In particular, be sure of the following:

    If the telephone number is outside your area code, the telephone number entry must exactly match what you would dial on a telephone to call the number. For example, for connections between two U.S. locations that are in different area codes, the entry must consist of 11 digits (1 +the area code + a 7-digit phone number).

    The word CONNECTED should appear at the end of each line.

    The rate should be appropriate for your location (typically 56 within the United States, 64 elsewhere); see also “About Transfer Rates” in Chapter 4.

Failed to Find Entry in /etc/ppp.conf

ppp[483] <connection name>: failed to find entry labeled `mars' in /etc/ppp.conf -- assume defaults

ppp[483] <connection name>: fatal error “LOGIN FAILED” on try #2

ppp[483] <connection name>: giving up for now

The message shown above means that there is a problem with adding a PPP connection.

  1. Select the Network and Connectivity category in the left-hand column of the System Manager window (see “Using the Interactive Guides” above). and click “ISDN Manager.”

  2. Select the connection that isn't working and click the Modify button.

    The Modify an Outgoing PPP Connection guide appears.

  3. Check your settings (see “Building a List of Remote ISDN Connections”).

Missing Devices or Device Types

Device Type ISDN wanted
Requested Device Type Not Found
Call Failed: NO DEVICES AVAILABLE

One or more of the above messages indicates that the file /etc/uucp/Devices is either missing information or is corrupted.

Verify that the file contains these two lines:

ISDN isdn/modem_b1 - 38400 direct
ISDN isdn/modem_b2 - 38400 direct

If the lines are missing, add them to the file and save the changes. Then restart the connection, as follows:

  1. In the panel that appears when you double-click the icon of the connection you want to use (in the PPP Manager), click Open Connection.

Error Messages From an Established Setup That Usually Works

This section lists various error conditions and messages that you may encounter when starting an ISDN connection that usually works. The messages may appear in your shell window or in the /var/adm/SYSLOG file.

For more informative error or status messages when trying to make a connection, follow these steps:

  1. Open a shell window and in the new window type:

    isdnstat

    When you place the call in the next step, isdnstat reports on the progress of the call. For more details, see the isdnstat man page. To stop isdnstat from running, type

    q

  2. In another shell window in which you're logged in as root, place the call and request additional information from PPP by typing

    ppp -r <connection name> -d

    The window in which you started isdnstat changes to show the progress of ISDN, and the window in which you typed the ppp command gives you information about PPP.

    You can request more information by adding additional -d flags to the ppp command line, but this will introduce security problems. See the ppp man page for details.

This section covers these error conditions:

Login Failed

ppp[348] <connection name>: fatal error “LOGIN FAILED” on try #2

ppp[348] <connection name>: giving up for now

This message may appear immediately (within three seconds) after trying to make the connection, or may appear after several more seconds.

If you see the message immediately, your system cannot access the ISDN line through your NT1 device, typically because the NT1 is powered off or the telephone line is unplugged. Check that all connections are solid and that the NT1 is powered on, then follow these steps:

  1. Open a shell window, log in as root, then type

    /etc/init.d/isdnd stop

    /etc/killall ppp

    /etc/init.d/isdnd start

  2. Wait 30 seconds, then try again, requesting more error or status information, by typing

    ppp -r <connection name> -d

  3. If you see the same error message, there may be a problem with the telephone company's switching software. Report the problem to the telephone company.

If you see the Login Failed message after several seconds, there is a different problem; for example, the remote system may be down or its ISDN connection may already be in use. For more information, follow these steps:

  1. Open a shell window, and in the new window type:

    isdnstat

    When you place the call in the next step, isdnstat reports on the progress of the call. For more details, see the isdnstat man page. To stop isdnstat from running, type

    q

  2. In another shell window in which you're logged in as root, place the call and request additional information from PPP by typing

    ppp -r <connection name> -d

    The window in which you started isdnstat shows the progress of ISDN, and the window in which you typed the ppp command gives you information about PPP.

Network is Unreachable

<connection name>: Network is unreachable

The above message means that your system cannot determine the correct route to the remote system. To add a route to the remote system:

  1. Select Network and Connectivity in the left-hand column of the System Manager window (see “Using the Interactive Guides” above). In the right-hand column, click Modify an Outgoing PPP Connection and follow the directions.

  2. On Page 9 of the guide, select Add Route.


Note: The add_route line establishes a static default route. If your Internet service provider or network administrator requires a different type of routing (for example, if you have a routing daemon turned on), contact that person and describe your problem. See also “Changing Network Routing” and the gated and routed man pages.


  1. Open another shell window and in the new window type:

    isdnstat

    When you actually place the call in the next step, isdnstat reports on the progress of the call. For more details, see the isdnstat man page. To stop isdnstat from running, type

    q

  2. In the shell window in which you're logged in as root, place the call and request additional information from PPP by typing

    ppp -r <connection name> -d

    The window in which you started isdnstat changes to show the progress of ISDN, and the window in which you typed the ppp command gives you information about PPP.

If you still cannot access the system, see “Changing Network Routing” in Chapter 4.

Unknown Host

<hostname>: Unknown host

The above message means that the system you are trying to access does not appear in your /etc/hosts file.

To repair the error, add the system to the /etc/hosts file as described in “Adding Remote Systems to the /etc/hosts File.”