VCS H323 Call disconnects

[gpsriramdc]

Hi ,

H323 call in VCS disconnected with Cause code of 31 (Normal Unspecified).In the Call log observe that Q931 malformed packet.

Is there any way we can decode the disconnect messages to find the disconnect cause.

Thanks in Advance

[awinter2]

Hi,

you can take a diagnostics log from the VCS with Network log level set to TRACE, this will log the incoming Q931/H225 packet and display the contents of the packet before the VCS attempts to decode it.

Another option is to get a network capture from the VCS while this packet is being received, either by means of port mirroring or by using 'tcpdump' directly from a root SSH shell on the VCS.

It is quite unusual to see decode errors for H323 traffic, do you know which endpoint/device is sending the packet which the VCS sees as malformed?

It could be the case that you have a firewall/NAT router in your network with H323 ALG/inspection enabled which is tampering with the packet in question, which is somehow breaking things.