User`s manual

U.S. Robotics I-modem Command Reference
Troubleshooting • Page 15-6
If the I-modem is set to a Þxed serial port rate (&B1) and your software is Þxed at 19200,
38400, 57600, or 115200 Kbps, the reason may be one of the following:
¥ Your computer may not support the higher serial port rate. If this is the case, Þx your
software rate at 9600 bps and disable high-speed V.32terbo modulation: ATS34=3 or
ATS34.0=1.1=1.
¥ If you use memory-resident programs (TSRsÐTerminate and Stay Resident programs) or
disk-caching programs, they may be interfering. Try disabling them before you run your
com-muni-cations software.
¥ Check that your software and the I-modem are set for the same kind of ßow control,
either hardware or software. Some communications programs also require that you dis-
able the kind you are not using. Send AT&F1.
CanÕt make 64 Kbps connections
Your long distance telephone service provider may not have ISDN support through its
entire network. As is usual in telecommunications, the slowest link determines the fastest
connection speed.