IMG 1010 - H.323 FastStart
Fast Start, also known as Fast Connect, bypasses some call setup steps in order to make it faster and allows the media channels to be operational before the CONNECT message is sent, which is a requirement for certain billing procedures.
The Fast Start procedure is optional in the network, but the IMG will always attempt it. If Fast Start fails due to unmatched preferred capabilities or because the remote end does not support Fast Start, then the IMG will fall back to TermCaps procedure.
For more information regarding the Fast Start procedure, refer to Version 2 of the ITU H.323 Specification.