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

Working with Call-legs (Dialogs) 69
Call-leg re-INVITE (Modify) State Machine
CALL-LEG RE-
INVITE (M
ODIFY)
S
TATE MACHINE
The Call-leg Re-Invite (Modify) state machine represents the state of a re-
INVITE process between two SIP UAs. A re-INVITE process can occur only
under the following conditions:
 A 2xx response was sent/received for the initial INVITE
(REMOTE_ACCEPTED or CONNECTED state for an
outgoing call-leg, ACCEPTED or CONNECTED for incoming
call-leg).
 There is no other pending modify process. (Pending Modify
means that a re-INVITE request was sent/received, but a final
response was not yet sent/received).
The RvSipCallLegReInviteStateChangedEv() callback reports call-leg modify
state changes and state change reason. The state change reason indicates how the
call-leg reached the new modify state. The re-INVITE process associates with
the following modify states:
RVSIP_CALL_LEG_MODIFY_STATE_IDLE
The initial state of the Re-INVITE state machine. Upon creation of a re-INVITE
object, it assumes the IDLE modify state. It remains in this state until
RvSipCallLegReInviteRequest() is called, whereupon it should move to the
REINVITE_SENT modify state.
RVSIP_CALL_LEG_MODIFY_STATE_REINVITE_RCVD
A re-INVITE request was received.
RVSIP_CALL_LEG_MODIFY_STATE_REINVITE_RESPONSE_SENT
A response was sent for an incoming re-INVITE request.
RVSIP_CALL_LEG_MODIFY_STATE_REINVITE_SENT
A re-INVITE request was sent.
RVSIP_CALL_LEG_MODIFY_STATE_REINVITE_RESPONSE_RCVD
A final response was received on an outgoing re-INVITE request.