Polycom VSX 3000 Administrator's Manual page 154

Administrator's Guide for the VSX Series
Symptom
Limited call rate in a
multipoint video call with at
least one audio-only IP
system.
Error message occurs
when placing an ISDN
(H.320) call.
The PBX does not accept
calls of type "unknown"
from the PRI network
interface module.
ISDN Calls do not connect
at the requested data rate.
A system using a
V.35/RS-449/RS-530
interface cannot receive
calls at certain speeds.
12 - 10
Problem
The call rate is limited to
64 kbps if the audio-only IP
system is called first.
An ISDN cause code is
received from the ISDN
line.
The highest-numbered
channel did not connect.
The system cannot make a
call if this channel does not
connect.
The ISDN switch type is not
configured correctly on the
VSX system.
The network interface
module is not connected
properly.
The PRI network interface
is not configured correctly.
Not all the ISDN B channels
connect.
V.35/RS-449/RS-530
systems cannot determine
how to allocate bandwidth
for call speeds that are
divisible by both 56 and 64
(such as 448K: 8 x 56K), so
the call cannot be
connected correctly.
Corrective action
Call all video systems before calling audio-only IP
systems.
Try the call again.
For more information, please refer to
Codes on page D-4.
Be sure you are calling the correct number. The
number may need to include:
• A digit for an outside line
• A long distance access code
• An international access code
• A country code
• An area code or city code
Check that all network cables are properly
connected.
Power off the system, wait five seconds, and power
on the system. Then wait about two minutes to allow
the ISDN lines to resynchronize.
Ask the person at the far site to call your system.
Check the ISDN configuration and verify with your
ISDN service provider that the system is configured
correctly.
Check the cables to the network interface module.
Verify that you have configured the system's PRI
network interface correctly. For detailed instructions,
see Configuring the PRI Network Interface
2-21.
Set the number of lines to be dialed to a lower
number. For more information on specifying the
number of lines, refer to Configuring the BRI Network
Interface on page 2-19.
Call the far site, or have the caller try again at a
different call speed.
Q.850 Cause
on page