3Com 3C892 - OfficeConnect ISDN Lan Modem Router User Manual page 94

Table 6 Symptoms, Causes, and Solutions
Symptom
A Multilink PPP call was
established but did not remain
connected.
Although only one data call is
connected, another voice or
data call cannot be placed.
Caller ID date and time are not
accurate.
Cannot place a call over the
LAN Modem's phone port
using a Sportster PC Card
modem.
Cannot place or receive two
simultaneous voice calls.
After placing a Multilink PPP
call, you lift the handset of a
telephone to place a call and
do not hear a dial tone.
Not receiving message
indication for Voice Mail or any
voice mail messages.
Cannot hear dial tone when
attempting to place a call using
an ISDN LAN Modem phone
port.
(continued)
Possible Cause
May be an incompatibility with
the router into which you are
dialing. Some remote routers split
the two B channels of a Multilink
PPP call between different
routing devices, preventing the
channels from being linked.
When the LAN Modem is
configured to Use 2 B channels
and the remote end disconnects
one of the 2 B channels, the LAN
Modem will disconnect the now
single B channel call since it's
configured to use 2 B channels.
A voice or data call may already
be connected leaving only one
B channel available.
The connected call may be
configured to always use two
B channels, leaving no bandwidth
available for another call.
Modem mistakes analog phone
line for digital line.
Your ISDN line may not support
simultaneous voice and data on
both B channels.
The handset was lifted to place a
call while the ISDN LAN Modem
was negotiating the Multilink PPP
call. Negotiation must be
complete before a call can be
placed.
Message Service box is not
checked.
Bandwidth Allocation may be set
to Use two B Channels.
Evaluating Symptoms and Solutions
Solution
Try reconnecting your call during off peak hours. If you
are still unable to establish a Multilink PPP call, contact
your ISP to confirm that they support this feature.
From the ISDN LAN Modem's home page, click Service
Providers and then select the provider you were
connecting to using Multilink PPP. For Bandwidth
Allocation, select Add second B channel as required.
Place the Multilink PPP call when both B channels are
available.
Check the bandwidth allocation setting for that service
provider. Refer to "Editing Service Provider
Chapter 6 for details.
Connect a workstation that has the correct time to the
ISDN LAN Modem and then turn the LAN Modem
power off and then on again. Once it is powered up,
launch your web browser and go to the LAN Modem's
main page at http://3Com.oc.lanmodem/
Add the following command to the Sportster modem
init string: AT ~~L0.
Check with your ISDN line provider to determine
whether or not your ISDN line supports 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.
Hang up the handset, wait a few seconds, and then try
again.
From the ISDN LAN Modem's main configuration page,
click ISDN Parameters. Under Supplementary Services,
check the box labeled Message Service.
Go to the appropriate Service Providers page and
change the Bandwidth Allocations setting to Add
second B channel as required.
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Profiles" in