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

Event Notification 239
Subscription API
RvSipSubsUnsubscribe(). It generates and sends a SUBSCRIBE message with
an “Expires:0” header, and updates the Subscription state machine to progress to
the SUBS_UNSUBSCRIBING state.
Note After receiving a successful UNSUBSCRIBE request, your application
should wait for a final NOTIFY message.
RvSipSubsRespondAccept()
When the notifier receives a SUBSCRIBE request, it can accept the request with
this function.
You can use RvSipSubsRespondAccept() in the SUBS_RCVD state to accept an
incoming subscription. You can also use this function to accept a Refresh
UNSUBSCRIBE request received by an established subscription. The user must
send a NOTIFY request with a “Subscription-State:active” header after calling
RvSipSubsRespondAccept().
RvSipSubsRespondPending()
When the notifier receives an initial SUBSCRIBE request, it can send a 202
pending response with this function.
You can use RvSipSubsRespondPending() in the SUBS_RCVD state to send a
202 response of an unauthorized incoming subscription. (The 202 response
indicates that the request has been received and understood, but does not
necessarily imply that the subscription has been authorized yet). The user must
send a NOTIFY request with a “Subscription-State:pending” header in it after
calling RvSipSubsRespondPending().
Note You can not send a 202 response to a Refresh UNSUBSCRIBE request; it
is only applicable to the first SUBSCRIBE request.
RvSipSubsRespondReject()
You can use this function in the SUBS_RCVD state to reject an incoming
subscription. You can also use this function to reject a REFRESH and
UNSUBSCRIBE request received by an established subscription.