Paradyne Comsphere 3920Plus Installation And Operation Manual page 216

Symptom
Intermittent disconnects, high error
rates, or excessive retransmissions
occur.
The modem establishes and then
disconnects the call.
High error rates occur when running
a local loopback or self-test.
Symptom
The data is scrambled.
Data is missing during a transfer.
Symptom
The MUX configuration option does
not appear under DTE Interface.
3920-A2-GN31-10
Table B-5
(2 of 2)
Modem — VF Connection
Perform an End-to-End test. Refer to Pattern located in the Test Branch section
of Chapter 3.
You may have a poor VF connection. Try dialing again.
The remote modem may have encountered an error control (EC) disconnect. If
the modems cannot negotiate EC, then a disconnect occurs.
The remote modem may be in a forced Error Control mode (disconnect if there
is no error control). Reconfigure your modem to V.42/MNP or Buffer and try
again.
Check the LCD to determine the reason for the disconnect.
Perform a Local Analog Loopback test.
Incoming rings can cause data errors during a loopback test. Abort the test,
disconnect the modular VF cord, and restart the test.
Table B-6
Online Operation
Verify that the character format (data bits, parity, and stop bits) is set to the
same value in both modems.
Verify that you are using the same method of flow control for both the modem
and the DTE.
If using XON/XOFF flow control, verify that the modem's parity matches the
DTE's parity.
Table B-7
Mux Operation
The Dial Access Security feature is enabled. Verify that both the Answer and
Originate security options are disabled. Refer to sections Set Answer Sec and
Set Orig Sec in Chapter 6.
The Dial Line Rate or LeasedLine Rate configuration option is set to an invalid
modulation. Refer to the Dial Line or Leased Line configuration option in the
Mux Enabled section of Chapter 4 for the valid rates.
April 1995
Action
Action
Action
Troubleshooting
B-5