IBM MWave 28800 Modem Does Not Function Properly with RAS

• Microsoft Windows NT Workstation versions 3.5 and 3.51
• Microsoft Windows NT Server versions 3.5 and 3.51

SYMPTOMS

Some models of the IBM MWave 28800 modems do not work with Remote Access Service (RAS) and other communications software. However, the same modems sometimes appear to function properly with Windows Terminal or other communications software.

CAUSE

The IBM MWave 28800 modems are not on the Windows NT 3.51 Hardware Compatibility List (HCL). Windows NT detects these modems as generic 28800 modems, and may drop connections intermittently.

RESOLUTION

To resolve this problem, update the existing Modem.inf file in the %Systemroot%\System32\Ras directory by appending the following information:

   ;----------------------------------------
   [Mwave 28800]
   <speaker_on>=M1
   <speaker_off>=M0
   <autodial_on>=ATDT
   <autodial_off>=ATX3D
   <speaker_on>=M1
   <speaker_off>=M0
   <hwflowcontrol_on>=&K3
   <hwflowcontrol_off>=&K0
   <compression_on>=%C1"H3
   <compression_off>=%C0"H0
   <protocol_on>=\\N7
   <protocol_off>=\\N0

   CALLBACKTIME=10
   DEFAULTOFF=compression
   MAXCARRIERBPS=28800
   MAXCONNECTBPS=57600

   DETECT_STRING=ATI3<cr>
   DETECT_RESPONSE=IBM Mwave Modem v3.0

   COMMAND_INIT=AT&F&C1&D2 V1 S0=0 S2=128 S7=55<cr>
   COMMAND_INIT=AT<hwflowcontrol><protocol><compression><speaker><cr>
   COMMAND_DIAL=<autodial><phonenumber><cr>
   COMMAND_LISTEN=ATS0=1<cr>

STATUS

This problem occurs when you use Windows NT 3.5 or 3.51 and IBM MWave modems.