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

72 HP-UX C SIP Stack Programmer’s Guide
Call-leg re-INVITE (Modify) State Machine
Figure 6-5 Call-leg Re-Invite (Modify) State Machine
IDLE
REINVITE
SENT
REINVITE
PROCEEDING
REINVITE
PROCEEDING
TIMEOUT
REINVITE
CANCELLING
REINVITE
RESPONSE RCVD
REINVITE REMOTE
ACCEPTED
REINVITE RCVD
REINVITE
CANCELLED
REINVITE FINAL
RESPONSE
SENT
ReInviteRequest()/
INVITE sent
1xx Recv
final response recv +
ACK sent
final response recv +
ACK sent
Cancel()/
CANCEL
sent
Cancel()/
CANCEL
sent
Provisional timer expired
2xx response recv
2xx response recv
INVITE recv
Cancel recv +
200 OK on cancel sent
Accept()/Reject()
final response sent
response
recv
REINVITE ACK
SENT
REINVITE ACK
RCVD
ACK recv
Accept()/
Reject()
final
response
sent
1xx sent (no
state change)
ACK sent
automatically
REINVITE TERMINATED
ReInviteAck()
ACK sent