We observed the following protocol issue when calling from a Skinny Phone at the Call Manager to a H.323 Gateway:
The call-manager initiates a call without faststart and H.245 tunneling to the gateway. The gateway provides a H.245 transport address within the alert message. The call-manager establishes the TCP connection for H.245. If the gateway does not send a TCS message within 4s the callmanager disconnects the call, without sending a TCS message itself.
There is no such timer defined in H.323, so that seems to be a non-compliance in the callmanager.
Is this a known issue?
Of course we could solve the problem on the gateway side but it should be fixed on the Call Manager