Paradyne 3800 manual 2 of, Modem - VF Connection, Symptom, Action, Table C-3

Troubleshooting

	Table C-3
	(2 of 2)
	Modem – VF Connection
Symptom	Action
Originate Mode	Verify that the modem’s DTE Dialer configuration option is set to the correct setting: either AT,
	DTR Dialing, V.25bis Async, V.25bis Bisync, or V.25bis HDLC.
Modem does not go	If using AT Dialing, refer to the Table C-2, Modem – DTE Connection.
off-hook and begin	If using DTR Dialing, verify the telephone number stored in directory location 1, and verify that
dialing
	the DTE is raising DTR from Off to ON to initiate a dial.
	If using V.25bis Async, verify that the correct character format is set to 7 data bits with even
	parity and 1 stop bit, and the carriage return and line feed are used as command terminators.
	If using V.25bis Bisync, verify that the correct character format uses two synchronous control
	characters and a start-of-text control character before the text block and an end-of-text control
	character after the text block.
	If using V.25bis HDLC, verify that the correct character format uses flag, address, and control
	characters before the text block and a frame sequence check and flag after the text block.
Modem dials but does	If the modem is operating behind a PBX, verify if a 9 and comma are needed before the
not connect	telephone number.
	Verify whether Tone or Pulse dialing is needed.
	Verify if one modem is configured for Error Control or Disconnect and the other modem is
	configured for no Error Control. Try calling in Buffer mode.
	If both modems use V.32bis or V.32 modulation, set the modem’s V.32bis Train configuration
	option to Long.
Intermittent disconnects,	Perform an End-to-End test. Refer to the Pattern section of Chapter 8, Test Branch.
high error rates, or
excessive
retransmissions
Modem establishes and	You may have a poor VF connection. Disconnect and dial again.
disconnects a call	The remote modem may have encountered an EC Disconnect, where the modem is
	configured to establish a call using error correction. 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 verify the reason for disconnect.
	Perform a Local Analog Loopback test.
High error rates occur	Incoming rings can cause data errors during a loopback test. Abort the test, disconnect the
when running a local	modular VF cord, and restart the test.
loopback or self-test

3810-A2-GB30-30 September 1998 C-3