ViewStation EX, ViewStation FX Administrator's Guide VS4000
Chapter 7 - Diagnostics and General Troubleshooting
© Polycom, Inc. 7-15
ISDN calls: 
ISDN Line Status 
icons do not turn 
green so ISDN calls 
cannot be 
completed.
All The call is not connecting 
properly.
Try the call again.
The system is not connected 
to an ISDN network.
Check the ISDN line connections. 
The ISDN number or SPID 
numbers are entered 
incorrectly. 
Note: The AT&T point-to-point 
protocol does not require 
SPIDs.
Make sure your ISDN numbers are 
entered correctly. Check the ISDN 
numbers with your service provider. 
Select the Clear icon on the Auto 
Detect SPIDs page, and then select the 
Start icon to automatically detect the 
new SPIDs. 
The system was not able to 
auto-detect SPIDs.
Check with your ISDN service provider 
and enter the SPIDs and switch 
protocol manually. 
The Quad BRI network 
interface module is directly 
connected to a U interface.
Install an NT-1 device between your 
network interface module and the ISDN 
connection.
The system is connected to an 
NT-1 then to a PBX. 
You do not need an NT-1device when 
connecting to a PBX. Connect the 
system directly to the PBX S/T 
connection. 
The ISDN line is provisioned 
incorrectly by the ISDN 
network service provider.
Check that your ISDN line is 
provisioned for Voice/Data, Voice/Data.
System displays a 
message indicating 
network congestion 
when placing an 
ISDN call 
immediately after 
starting the system
All This can occur if the system 
uses a PRI E1 network 
interface module that is 
connected to an Adtran Atlas 
800 Plus module. After power 
on, the Adtran module must 
complete channel restarts 
before the system can 
complete ISDN calls.
Wait about three minutes and try the 
call again.
Cannot make 
bonding calls. (The 
call progress circles 
only show blue or 
yellow.)
All Switch protocol issue. Start by calling the far site at 1x56, 
1x64, 2x56, or 2x64 Kbps, as 
appropriate. This will verify the primary 
number. If these calls complete, try 256 
Kbps, then 384 Kbps.
Being able to make non-bonded calls 
but not bonded calls to all locations is 
usually a switch protocol issue. Verify 
your ISDN provisioning with the 
telephone service provider.
Symptom System Cause Solution










