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

100 HP-UX C SIP Stack Programmer’s Guide
Transaction API
RvSipTransactionStateChangedEv()
This event is probably the most useful of the events that the SIP transaction
reports. Through this function, you receive notifications of SIP transaction state
changes and the associated state change reason and your application can act
upon the state. For example, upon receipt of a
SERVER_GENERAL_REQUEST_RECEIVED state notification, your
application can respond with a desired response code.
RvSipTransactionMsgToSendEv()
The transaction calls this event whenever a transaction-related message is ready
to be sent. You can use this callback for changing or examining a message
before it is sent to the remote party. The transaction will not notify you about
retransmissions of messages.
RvSipTransactionMsgReceivedEv()
The transaction calls this event whenever a transaction-related message has
been received and is about to be processed. You can use this callback to examine
incoming messages. The transaction will not notify you if the message is a
retransmission.
RvSipTransactionInternalClientCreatedEv()
Notifies the application that a new client transaction was created by the
SIP Stack. The newly created transaction always assumes the IDLE state. This
callback is called only for client transactions that are created automatically by
the SIP Stack (not by calling the function,
RvSipTranscMgrCreateTransaction()). Such transactions are the CANCEL and
PRACK transactions.
RvSipTransactionCancelledEv()
Notifies that a CANCEL request is received on an INVITE or a General
transaction.
RvSipTransactionOpenCallLegEv()
When a request that is suitable for opening a dialog (INVITE/REFER/
SUBSCRIBE with no To tag) is received, the Transaction layer asks the
application whether to open a call-leg for this transaction. For a proxy
application, the callback is called for INVITE/REFER/SUBSCRIBE methods. It
can be used by proxies that wish to handle specific requests in a call-leg context.