VoIP > SIP Extensions

SIP Extensions

Support PRACK method with provisional response reliability
Encode SIP URI with user parameter
Disable Call Waiting (Reject second incoming call)
Disable Caller-ID Display
Call Hold using c= (RFC 2543) in SDP
send NOTIFY for REFER request

SIP Timers

Send INVITE with Timer header value: Seconds
SIP Session Timer value: Seconds
Conditional Call Forwarding Timer: Seconds
SIP T1 Timer: Milliseconds
SIP T2 Timer: Milliseconds
SIP T4 Timer: Milliseconds