Microsoft KB Archive/130359

= Windows NT 3.5 RAS: Buying a Supported 28,800 bps Modem =

Article ID: 130359

Article Last Modified on 11/1/2006

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APPLIES TO


 * Microsoft Windows NT Workstation 3.5
 * Microsoft Windows NT Server 3.5

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This article was previously published under Q130359



SUMMARY
This article lists high speed (28,800 bits per second [bps]) V.fast and V.34 modems supported by Windows NT 3.5 Remote Access Service (RAS) that are not on the printed Windows NT 3.5 Hardware Compatibility List (HCL).

This article also discusses the V.fast and V.34 communication standards and how they affect RAS. This information can be used to help you decide which modem to buy, or if you already bought a modem, how to make your modem work with RAS.

NOTE: The V.fast standard is also known as V.fc. The fc in V.fc stands for fast class.



MORE INFORMATION
If you want to buy a supported modem for use with RAS, you should look for a modem on the list below. When Windows NT 3.5 was released the final version of the V.34 communication standard had just been defined and not many V.34 modems were available. Therefore, most supported high speed modems comply only with the temporary V.fast standard.

V.fast Modems, V.34 Modems, and Modems Supporting V.fast and V.34
By early 1995, manufacturers provided upgrade paths for many of the listed modems to support both V.fast and V.34 simultaneously. While there is no guarantee that these upgraded modems are compatible with RAS, the chances are good that they will work with RAS. However, if a V.fast modem was upgraded to only support V.34, chances are higher that it has become incompatible with the current driver in the RAS MODEM.INF file.

If you know how to use modem commands and know the syntax of the MODEM.INF file, you can modify the MODEM.INF file to make your modem work with RAS. If you buy an upgraded version of a V.fast modem listed below that now supports both V.fast and V.34, few or no changes to the MODEM.INF file are required. However, the modem may only be able to negotiate the V.fast standard with another modem when used with the current RAS MODEM.INF file. This can be a problem when you call a RAS server that has a plain V.34 modem. The V.34 standard does not define fall back to V.fast during protocol negotiation, therefore your modem will connect using V.32bis, the next lower communications standard which allows only 14,400 bps connections.

If you need to modify the MODEM.INF file, see the Modifying MODEM.INF topic in the Windows NT RAS Help file and refer to your modem command reference manual.

If your modem is not on the supported list, check with your modem manufacturer about the availability of a custom Windows NT RAS MODEM.INF file section to make your modem work with RAS. If your manufacturer has a MODEM.INF section for only Windows for Workgroups 3.11 RAS, you can use that section with Windows NT. If you use a Windows for Workgroups RAS MODEM.INF section, Windows NT RAS will not be able to autodetect your modem. However, this should not be a problem, because you can select your modem driver manually.

V.fast and V.34 Modems Supported by Windows NT 3.5
The Windows NT 3.5 MODEM.INF file supports the following 28,800 bps V.fast and V.34 modems. These are external modems, unless otherwise noted. There are only two V.34 modems listed.

The Modem Names in MODEM.INF column lists the supported modems by using the titles of the modem sections exactly as they appear in the MODEM.INF file. These titles also appear in Windows NT Control Panel in the RAS modem selection list, but without the square brackets. The list shows US modems in alphabetical order and three German modems at the end.

The Supported Standards and Comments column gives some additional information, but is not a complete list of modem features.

Modem Names in MODEM.INF          Supported Standards and Comments

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===========          ===================================== [Boca Modem V.Fast Class]          V.fast [Codex V.34R]                     V.34 [MicroCom DeskPorte FAST ES28.8]  V.fast + MNP10 + Fax [MicroCom DeskPorte FAST]         V.fast + MNP10 + Fax 9600 bps. Parallel port is not supported in Windows NT. [Hayes Accura 28800]              V.fast [Hayes Optima 28800]              V.fast [MultiTech MultiModem MT2834]     V.fast [Practical Peripherals PM288PKT]  V.fast + Fax 14400 bps. Pocket modem. [Practical Peripherals PC288MT]   V.fast [Practical Peripherals PC288SA]   V.fast [Supra Fax Modem 288]             V.fast + Fax [Supra Fax Modem 288 internal]    V.fast + Fax [UDS Motorola V.3400]             V.34 [US Robotics Sportster 28800 VFC] V.fast [Zoom VFP 28.8 internal]          V.fast [Creatix LC288FC - GER]           V.fast. GER= German Modem [ELSA MicroLink 288ooTL - GER]    V.fast. GER= German Modem [LOGEM 928 - GER]                 V.fast. GER= German Modem

The products included here are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.

Additional query words: prodnt 28.8 Kbps 28.8baud 28800bps 28800 28,800bps baudrate baud

Keywords: KB130359

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