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Adding Support for ADTRAN ISDN Products to Windows® NT 3.5 Operating System

Adding Support for ADTRAN ISDN Products to Windows® NT 3.5 Operating System

Article ID: 1550

  Adding Support for ADTRAN ISDN Products to Windows® NT 3.5 Operating System


Adding Support for ADTRAN ISDN Products to Windows® NT 3.5 Operating System


winnt35.adn (, )

Installing ISU Support in Windows NT 3.5 Operating System

Windows NT Quick Setup

  1. Add the contents of winnt35.adn to the device section of the Windows NT modem.inf file.
  2. Reconfigure Windows NT network settings to utilize the newly added ADTRAN device(s).
  3. Refer to ISU Setup below to configure the ISU device.

Windows NT Detailed Setup

  1. Insert the contents of winnt35.adn into the Windows NT modem.inf file by using the following procedure:

    • Open the modem.inf text file located in the WINDOWS\SYSTEM32\RAS directory (directory example is an i386 FAT system).
    • Insert the contents of the ADTRAN file winnt35.adn. Place this file after the global response section and before the first existing entry.
    • Save the modem.inf file. Details of adding an entry to the modem.inf file may be found in the Windows NT on-line help.

  2. Open the Control Panel to Network settings and select Remote Access Service from the installed Network Software box (assuming RAS has been installed).
  3. Select Configure, and ADD for the desired COM port (remove any existing device from the COM port to be used). NOTE: The supplied setup runs the port at 115.2 kbps. The PC must be able to handle the selected bit rate. A 16550 UART in the communications hardware of the PC is recommended for all rates above 19.2 kbps. Depending on the applications being run and processing power of the PC, a processor-assisted communications interface may be required for the highest speeds (57.6 and 115.2 kbps).
  4. Select CANCEL for the AUTODETECT option.
  5. Select the ADTRAN ISU file from the Attached Device list. Set port usage as desired.
  6. Select settings and configure parameters as desired (the ISU device has no speaker, hardware flow control is recommended, error correction and compression apply only to V. 32 bis mode). If your ISU unit has no internal modem, disable error correction and compression.
  7. Select OK and accept all current control panel network settings. It should not be necessary to restart the machine.
  8. Start Windows NT Remote Access.
  9. For dial-out do the following:

    • Select either Add or Edit a phone book entry.
    • After entering a name, number, and description, select Advanced Settings.
    • For ISU models other than the ISU Express, select ADVANCED and then the modem Icon to verify that the initial port speed is set to 115200. For the ISU Express, set port speed as desired.
    • Verify the hardware features are set as desired. Again, if your ISU has no internal modem, disable error control and compression.
    • Set other phone book entry options as desired.

  10. For server operation (dial-in), start the remote access server as usual after setting up the ISU device as described below:

ISU Setup
Using the front panel of the ISU 128 or 2x64, or the terminal interface to the ISU Express, set the following parameters on the ISU device.

  1. Referring to the ISU Users manual and the ISDN information supplied by the telephone company, enter the switch type, Service Profile Identifier (SPID) number(s), and line directory numbers (LDNs) as required.
  2. If you are using an ISU 128 or 2x64, load the Quick Set-Up Option 'Dial 115.2 async' from the ISU front panel.
    NOTE: ISU 128 versions prior to H.53 and ISU 2x64 versions prior to B.44 also require that AT commands be enabled.
  3. Power the ISU unit off and then back on.

Setup is complete.

Overview of the ISU Setup Performed by winnt35.adn

For maximum system flexibility, much of the ISU setup is built into the setup string sent by the Windows NT operating system when using the winnt35.adn. However, due to the nature of ISDN equipment, and since the ISU 128 and ISU 2x64 do not support autobaud (before 2Q95) and default to a synchronous data terminal equipment (DTE) setting, some initial manual configuration of the ISU device is required as shown in the installation procedure above.

Due to the many options available when making an ISDN connection with ADTRAN ISU units, it is not feasible to create setup strings to cover every combination of options. The strings supplied are targeted to cover typical applications. If the strings supplied in the winnt35.adn file do not meet your needs, use the ISU user manual and Windows NT manual to alter the supplied settings as desired.

WARNING: Use extreme caution if editing this file. It is highly recommended that you be familiar with the requirements in the Windows NT documentation before attempting to alter this file. As a minimum, make a backup copy of the file before editing.

The pre-defined setup strings provided in the winnt35.adn file cause ADTRAN ISU devices to be setup as follows:

ADTRAN ISU - using string AT&F8&C1&D2V1X1&R0S0=0S2=128S7=55S54=11\Q3&R0

  • Service Type -ISDN Dial
  • Call Type -64 kbps data
  • Data Protocol -Fallback
  • DTE Mode -Asynchronous 2
  • Data Bits -8
  • Parity Bits -None
  • Stop Bits -1
  • DTE Rate -115.2 kbps
  • DTE Flow Control -Hardware (RTS/ CTS)
  • Dial -AT commands
  • DTR -Off when Idle (DTR disconnects)
  • DCD -Normal (On when connected)
  • Escape Sequence -Disabled

ADTRAN ISU+V32b - using string AT&F8&C1&D2V1X1&R0S0=0S2=128S7=55S54=11\Q3&R0

Same setup as above but includes modem specific commands to enable/disable modem error correction and compression.

  • \N0 -disables modem error correction
  • \N3 -enables modem error correction
  • %C0 -disables modem compression
  • %C1 -enables modem compression

NOTE: Windows NT disables the escape sequence or break in character. This disables the ability to go into command mode while on-line by entering +++. To re-enable the normal ISU escape sequence for other applications, manually enter the command s2=43&W.
Using fallback, the ISU unit attempts to connect using BONDING Mode 1 (2 B channels). If unable, the ISU device will fallback to V.120 (1 B channel), then T-link, and finally V.32 bis (if the ISU device contains the internal modem option). The DTE rate remains at 115.2 kbps. When using fallback, protocol negotiation may be controlled by setting the call type. The call type may be set on the fly when dialing by using a # command in the dial string.

Protocol Fallback
#464 kbps data(1) Bonding (2) V.120 (3) T-link (4) V.32bis
#356 kbps data(1) V.120 (2) T-link (3) V.32bis
#2AudioV.32bis only
#1SpeechV.32bis only

Example: 'atd 555 1212 #3' originates a call and forces negotiation to begin with V.120 instead of BONDING, by setting the call type to 56 kbps data. Refer to the ISU User Manual for more detail on using the FALLBACK feature.

Changes to any of these pre-defined settings (with the exception of DTE rate and data format on the ISU Express) require the user to manually edit the strings in the INF file.

NOTE: ISU 128 firmware J.03 has some compatibility issues with the Windows NT operating system but has been enhanced to provide compatability in newer versions.

If you experience any problems using your ADTRAN product, please contact ADTRAN Technical Support.

Windows and Microsoft are registered trademarks of Microsoft Corporation.

Version history
Last update:
‎02-28-2012 01:57 PM
Updated by: