3Com 3C892 - OfficeConnect ISDN Lan Modem Router User Manual page 95

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HAPTER ROUBLESHOOTING AND
Table 6 Symptoms, Causes, and Solutions
Symptom
Cannot receive an incoming
call.
The analog modem connected
to the ISDN LAN Modem is
unable to detect dial tone
when attempting to place an
analog call while a Multilink
PPP call is established.
Cannot conference, transfer,
or drop voice calls.
Caller always hears a ringing
signal even when line is busy.
(continued)
M
AINTENANCE
Possible Cause
Attempted to place a voice call
over a directory number that is
already in use for a data call. If
this is the case, your ISDN line is
configured to allow only one B
channel per directory number.
Bandwidth Allocation may be set
to Use two B Channels.
Two separate data calls are up.
Your ISDN line does not support
simultaneous voice and data on
both B channels.
Your ISDN line does not have
ACO.
The standard period of time most
modems are set to wait for a dial
tone before hanging up the call is
2 seconds, which is about the
same amount of time it takes the
ISDN Modem to drop the second
B channel from a Multilink PPP
call and re-establish a dial tone.
Flexible calling is not enabled.
Your telephone company uses
older codes for these services.
Message service is enabled on the
ISDN LAN modem but you do not
subscribe to voice mail from the
telephone company.
Solution
Contact you telephone company if you want to have
simultaneous voice and data on both B channels.
For a Lucent 5ESS switch, your ISDN line must have
Max B Channel Limit=2 for simultaneous voice and
data.
For a Siemens switch, your ISDN line must have
Number of B Channels Per Call Type Per Office
Equipment Directory Number (NBCCTOEDN) =2.
Contact you telephone company if you want to have
simultaneous voice and data on both B channels.
For a Lucent 5ESS switch, your ISDN line must have
Max B Channel Limit=2 for simultaneous voice and
data.
For a Siemens switch, your ISDN line must have
Number of B Channels Per Call Type Per Office
Equipment Directory Number (NBCCTOEDN) =2.
Contact you telephone company to have ACO added.
Adjust the analog modem setting as follows: Change
S-Register 6 (Wait Time for Blind Dialing) on the analog
modem to a value of 3 or higher (the default is usually
2) to increase the period of time your analog modem is
set to wait before hanging up the call.
From the ISDN LAN Modem's main configuration page,
click ISDN Parameters. Under Flexible Calling Enabled,
check the telephone number check box for which you
want Flexible Calling enabled.
If Flexible Calling is enabled on the ISDN LAN Modem,
check with your telephone company to make sure it is
enabled on your ISDN line.
From the ISDN LAN Modem's main configuration page,
click ISDN Parameters. Under Supplementary Services,
enter the following in the Codes field: 6 for
Conference, 7 for Transfer, 8 for Drop and 9 for
Message Service.
From the ISDN LAN Modem's main configuration page,
click ISDN Parameters. Under Message Service Enable,
make sure both boxes are clear.