HP-UX C SIP Stack Programmer's Guide (Novembery 2007)

52 HP-UX C SIP Stack Programmer’s Guide
Call-leg State Machine
responsible for moving the PRACK state machine using the Call-leg PRACK
API. You can find the different PRACK states in the RvSipCallLegPrackState
enumeration.
RvSipCallLegProvisionalResponseRcvdEv()
The call-leg calls this callback whenever a provisional response has been
received.
BYE R
EQUEST
C
ALLBACKS
The following two callbacks are called when a BYE request is received. If the
application does not implement the following callbacks the SIP Stack
automatically accepts the BYE and terminates the call-leg.
RvSipCallLegByeCreatedEv()
Notifies the application that a new BYE transaction has been created. The
application can exchange the transaction handles with the SIP Stack using this
callback. The application can specify weather it wishes to handle the request. If
so, it will be notified of the BYE transaction states and will have to respond to
the BYE request.
RvSipCallLegByeStateChangedEv()
Through this callback function you receive notifications of SIP call-leg server
BYE state changes and the associated state change reason. The application can
decide whether to accept or reject the BYE request with the functions
RvSipCallLegByeAccept() and RvSipCallLegByeReject().
For more information on the above functions, see the SIP Stack Reference
Guide.
CALL-LEG STATE
M
ACHINE
The Call-leg state machine represents the state of the session setup between two
SIP UAs. The RvSipCallLegStateChangedEv() callback reports call-leg state
changes and state change reasons. The state change reason indicates how the
call-leg reached the new state.
BASIC CALL-LEG
S
TATES
Some of the call-leg states are basic and common to most call-leg scenarios.
Advanced call-leg states depend on SIP Stack configuration. The call-leg
associates with the following basic states: