Polycom VSX 3000 Administrator's Manual page 171

Symptom
Error message occurs
when placing an ISDN
(H.230) call.
The PBX does not accept
calls of type "unknown"
from the PRI network
interface module.
A system using a
V.35/RS-449/RS-530
interface cannot receive
calls at certain speeds.
Cannot dial remote system
in BONDING 384 K calls.
(The call progress circles
only show blue or yellow.)
Problem
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.
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.
Switch protocol issue.
Diagnostics and General Troubleshooting
Corrective action
Try the call again.
For more information, please refer to
Codes on page Appendix-6.
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
3-16.
Call the far site, or have the caller try again at a
different call speed.
Start by calling the far site at 1x56, 1x64, 2x56, or
2x64K, as appropriate. This will verify the primary
number. If these calls complete, try 256K, then 384K.
Being able to dial non-bonded but unable to dial
bonded to all locations is usually a switch protocol
issue. Verify your ISDN provisioning with the
telephone service provider.
Q.850 Cause
on page
7 - 15