3Com ISDN Modem User Manual page 110

8-6 C
HAPTER
Table 8-1 Symptoms, Causes, and Solutions
Symptom
A connection has
been established
(B-1 or B-2 green
LED remains lit
and you receive a
CONNECT
message) but data
cannot be sent
Upon power up,
both the TEST and
D channel LEDs
flash
Both B1 and B2
LEDs flash when
the D channel
lights
Cannot place or
receive two
simultaneous calls
DTR LED does not
remain lit after you
have started your
communication
application
(Continued)
8: T
ROUBLESHOOTING
Possible Cause
There is an interoperability
mismatch between the local
and remote applications.
A previous firmware
download did not complete
successfully.
The 3C882 ISDN modem baud
rate is set to 230.4 Kbps. or to
a fixed rate (i.e., Autobaud is
disabled).
Your ISDN line has not been
provisioned for simultaneous
voice and data.
Communication between the
ISDN modem and your PC has
not been successfully
established.
Solution
Make sure that the local and remote
data applications have
communications capability and are
properly configured.
Ensure that the baud rates for each
application are set to an equal value.
Download the firmware. Refer to the
readme file for firmware download
instructions.
Ensure that your computer's COM port
supports 230.4 Kbps or change the
COM port setting of either your
computer or the ISDN modem so that
both devices are set to the same COM
port rate.
Check your ISDN line provisioning.
Ensure that simultaneous voice and
data has been provisioned for both
directory numbers.
Verify that the 3C882 ISDN modem is
powered on.
Verify that the COM port cable is
firmly connected to the COM port on
your PC and the COM port on the
3C882 ISDN modem.
Verify that the correct COM port (the
one to which the 3C882 ISDN modem
is connected) is selected in your
communications application.