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

112 HP-UX C SIP Stack Programmer’s Guide
Transaction State Machine
SERVER INVITE
T
RANSACTION STATE
MACHINE
Figure 7-4 Server INVITE Transaction State Machine
Invite Request rcvd
(Request Rcvd)
IDLE
Respond Reliable(1xx)
reliable 1xx sent
REL PROV SENT
TERMNATED
Respond (2xx-6xx)
ACK rcvd
PRACK
COMPLETED
Prack Recvd
+ response sent
Respond Reliable(1xx)
reliable 1xx sent
Terminate(),
Transaction Timeout
inviteLingerTimer
Respond (2xx-6xx)
Respond (2xx-6xx)
Terminate()
time out(T1, 2*T1, 4*T1,...)
retransmission
Respond(1xx)
1xx sent *
PROXY 2xx
RESPONSE SENT
RespondMsg (2xx
(for proxy only))
Terminate(),
Transaction Timeout
(proxy 2xx sent timer
(for proxy only)
ACK RCVD
Terminate(),
Transaction Timeout
T4 - for UDP,
0 - for TCP)
Respond(1xx)/
1xx sent *
Invite rcvd-
send last 1xx response*
FINAL
RESPONSE SENT
time out (T1, 2*T1, ...,T2)
retransmit final response*
INVITE RCVD
* No state change
Respond
(500)
on time out