Hi Guys.

I have the following problem,

When the call desk receives calls and wants to transfer those call, the telephone resets itself, and gives the following error “Call Control Failure”.

Note: This does not happen all the time.

The voice guys have been doing some troubleshooting by placing packet sniffers along the path of the voice traffic.

What they found is that the firewall is resetting\block some of the signaling traffic that are being send from the CCM to the phone.

They picked this up by watching the sequence number of packets leaving the CCM. The packets with the same sequence number never pass trough the firewall.

I don't get any info from the logs.

My setup

PIX 525 - 6.3(5)

Call Desk - Attended Console

I have removed the skinny fixup

Hub and Spoke design.