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

Working with Transactions 95
Transaction API
Transaction Timers and Retransmissions Count
According to RFC 3261, the transaction has to set different timers during its life
cycle and perform different actions when the timers expire. For example, after
sending a final response, the transaction has to set a timer to the value of 32,000
msec. When this timer expires, the transaction must terminate. The values of the
transaction timers are taken from the Stack configuration and are determined
upon initialization. The application can use a Set function and change the
different timer values of the transaction. The application can also control the
number of retransmissions performed by the transaction.
Persistency Definition and Used Connection
When working with TCP, the application can instruct the transaction to try and
locate a suitable open connection in the connection hash before constructing a
new connection. The application can also instruct the INVITE transaction to try
and send both INVITE and ACK on the same connection. For more information
on persistency level and Persistent Connection API functions, see Persistent
Connection Handling of the Working with the Transport Layer chapter.
Current Local Address
For client transactions, the local address that was actually used for sending the
request. For Server transactions, the local address on which the request was
received. The transaction will always send the response from the same local
address on which the request was received.
Current Destination Address
The address to which the transaction is about to send a message. This address is
available only in the context of the RvSipTransactionFinalDestResolvedEv()
callback.
Received From Address
The address from which the transaction has received the last incoming message
(request or response).