3Com DIGITAL MODEM

Troubleshooting Tips 3-3

Check the Service Proﬁle Identiﬁer (SPID) entry and the

Phone# information in the digital modem software

conﬁguration utility.

If you have veriﬁed once again that your SPID and Phone#

parameters are entered properly and the D channel LED

continues to ﬂash without going out, call your telephone

company, verify that you have been given the correct SPID

and Phone# information, and ask whether the ISDN line is

Point-to-Point. If the ISDN line is Point-to-Point, be sure not

to include the SPID in the conﬁguration.

Also verify that the telephone company has conﬁgured

the ISDN line properly for the 3Com Impact digital

modem product (see Table 1-1). If the D channel LED

does not go out after these veriﬁcations, call your reseller

for line conﬁguration and troubleshooting assistance.

■If the D channel LED goes out, the digital modem is ready

to place and receive calls.

If you have a standard analog telephone attached to the

digital modem’s analog voice port, you can place a voice

call in the normal fashion. You should have the ability to

obtain a dial tone, enter digits, and connect to your

destination. While the voice call is being placed, either

the B-1 or B-2 channel LEDs will ﬂash yellow. Once the

voice call is connected and the other party picks up the

phone, the B-1 or B-2 LEDs that were ﬂashing will now

remain lit until the call is disconnected.

If you do not hear a dial tone or cannot establish a call,

there is most likely a problem with the conﬁguration of

your ISDN line. Call the telephone company and have it

verify that your line is conﬁgured for circuit-switched

voice and data service.

6Monitor the B-1 and B-2 LEDs.

Data calls typically involve more interactions than voice calls do.

Your computer, applications software, or the remote destination

can prevent establishment of a data call. If you have been able

to perform all of the above steps, your 3Com Impact digital

modem is most likely functioning correctly.