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

114 HP-UX C SIP Stack Programmer’s Guide
Transaction State Machine
CLIENT CANCEL
T
RANSACTION STATE
MACHINE
Figure 7-5 Client CANCEL Transaction State Machine
SERVER CANCEL
T
RANSACTION
A transaction may assume any of the following states in the Server CANCEL
state machine:
CANCEL
REQUEST
SENT
Cancel( )/
Cancel Sent
(user command)
IDLE
TERMINATED
2xx-6xx Recv
Terminate(),
Transaction Timeout
(generalRequestTimeoutTimer)
CANCEL
PROCEEDING
Terminate(),
Transaction Timeout
(generalRequestTimeoutTimer)
1xx Recv
(provisional response)
1xx rcv d /
timeout(T2) -
Request Sent
(retransmission)*
Transaction Timeout
(T1, T1*2,T1*4...T2) -
Cancel Sent
(retransmission)*
2xx-6xx Recv
CANCEL FINAL
RESPONSE
RCVD
Terminate()
Transaction Timeout
(T4 - for UDP,
0 - for TCP)
* No state change