H323

H323 Signalling Messages 

— I will complete the whole signalling soon —

H225/Q931 CALL SETUP

SETUP   :  source&dest address,port

CALL PROCEEDING

ALERTING : ringback tone

The called telephone starts ringing and this is signalled to the other party with the Q.931/H.225.0 message Alerting.

H245 NEGOTIATION AND VOICE PATH SETUP

CONNECT  (Q931/H225) : create h245 channel

The called party picks up the handset and the endpoint can signal the call has been accepted. This is done by sending the Q.931/H.225.0 message Connect. At this point, the parties will need to negotiate parameters for audio (and optionally video) channels. The protocol H.245 is used for this negotiation. In the default case, H.245 will need another TCP channel, so the endpoint 122 will insert its H.245 address (the IP address and port where it listens for H.245 connections) into […]