MultiModemDSVD User Guide | 5 Solving Problems |
4If you were online with a BBS or an online service like CompuServe, it might have hung up on you because of lack of activity on your part or because you ex- ceeded your time limit for the day. Try again.
The Modem4Cannot Connect When Answering
Autoanswer might be disabled. Turn on autoanswer in your datacomm program or send the command ATS0=1 (ATS0=2 if you have Caller ID service) to your modem in terminal mode.
File Transfer4Is Slower Than It Should Be
You might have an older UART. For best throughput, install a 16550AFN UART or a
4on how to identify your UART.
If you are running under Windows 3.1 and have a 16550AFN UART, you must replace the Windows serial driver, COMM.DRV, to take full advantage of the UART’s speed.
If you are using a slow transfer protocol, such as Xmodem, try Zmodem or Ymo-
4dem/G instead.
Is your line noisy? If there is static on your line, the modem has to resend many blocks of data to insure accuracy. You must have a clean line for maximum
4speed.
Are you downloading a compressed file with MNP 5 hardware compression en- abled? Since hardware data compression cannot compress a file already compressed by an archiving program, the transfer can be marginally slower with
4data compression enabled than with it disabled.
Does your Internet service provider (ISP) use the same 56K protocol as your mo- dem? The default setting of your modem is to connect using either the K56flex or the V.90 protocol, depending on which one the ISP modem is using. If your ISP uses the X2 protocol, the maximum speed you will be able to connect at is 33,600
4bps. Check with your ISP to see which protocols it supports.
Try entering the &V1 command to display information about the last connection, making a screen print of the connection statistics, and checking for parameters that might be unacceptable.
Data Is Being Lost
If you are using data compression and a high speed serial port, set the serial port
4baud rate to four times the data rate.
Your UART might not be reliable at serial port speeds over 9600 bps or 19,200 bps. Turn off data compression, reset your serial port speed to a lower rate, or replace your serial port with a faster one.
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