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

380 HP-UX C SIP Stack Programmer’s Guide
SIP Session Timer
RvSipCallLegTranscSessionTimerSetPreferenceParams()
Sets the preferred Session Timer parameters associated with this transaction.
The only general transaction allowed is “UPDATE”. These parameters may not
be equal to the Session Timer parameters of the call at the end of the negotiation.
If an UNDEFINED value is set as the minSE, it is configured as the default (90
seconds) according to the Session Timer RFC and the Min-SE header will not
appear in the upcoming sent message that is related to this transaction.
If the sessionExpires parameter is set to 0, the Session-Timer mechanism is
turned off immediately in the current call-leg. Moreover, the Session-Timer
mechanism can be turned on by:
 Calling this function with non-zero sessionExpires value in the
middle of a call.
 Calling one of the Session-Timer Call-leg API functions for
refreshing the current session
(RvSipCallLegTranscSessionTimerGeneralRefresh() or
RvSipCallLegSessionTimerInviteRefresh()).
RvSipCallLegTranscSessionTimerGetNegotiationParams()
Gets the negotiation Session Timer parameters associated with this transaction.
These parameters may not be equal to the Session Timer parameters of the call
in the end of the negotiation.
CONTROL FUNCTIONS The following Control functions are provided for session time support:
RvSipCallLegSessionTimerRefresh()
Causes a re-INVITE to be sent in order to refresh the session duration. This
function can be called only in the CONNECTED state when there is no other
pending re-INVITE transaction. The response of the remote party to the re-
INVITE will be given in the RvSipCallLegModifyStateChangedEv() callback.
RvSipCallLegTranscSessionTimerGeneralRefresh()
Creates a transaction related to the call-leg and sends a Request message with
the given method in order to refresh the call. The only general transaction
allowed is “UPDATE”. The request will have the To, From and Call-ID of the
call-leg and will be sent with a correct CSeq step. It will be record routed if
needed. The request will contain all the parameters related to the Session Timer.
CALLBACKS The Call-leg Session Timer API defines the following callback functions: