Congestion on Local and Outgoing Calls


I am using
PBX Firmware: 6.12.65-25
PBX Service Pack:

Im having a problem in which every day I receive Failed calls from local and outgoing calls.

Upon checking the CDR Report, all Failed dispostion gave App value of Congestion.

I also validated the destination number and were able to call to it manually.
What is the cause of this. Even in local calls we are experiencing CONGESTION

I have a vicidial server that is trunked to FreePBx with Caller ID <000000000>
FreePBx have a ISDN Card, FreePBX outgoing and incoming call is using ISDN.


ISDN PRI is 23 channels, max.

Could that be part of it?

Also is the trunk set for a value of less than 23 max outbound calls.

our ISDN PRI have 30 channels.

I did not set a call-limit in our ISDN.

And what im worried about is that even in local calls I experience CONGESTION.

Example is EXT 701 calling EXT 702 and being CONGESTED.