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

96 HP-UX C SIP Stack Programmer’s Guide

Transaction API

Is UAC

Transactions have a client side and a server side. The client side is known as a

client transaction and the server side as a server transaction. The client

transaction sends the request, and the server transaction sends the response. The

Is UAC parameter indicates whether or not the transaction is a client

transaction.

New Header Handles

Some of the transaction fields are message parts. For example, the To header

field is a Party header object. Before setting a parameter of this type in the

transaction, you should request a new handle for the parameter from the

transaction. After initializing the message part, you can set it back in the

transaction.

Transmitter

Each transaction holds a single transmitter and uses it to send SIP messages and

message retransmissions. The transaction creates its transmitter upon

initialization and terminates it only upon destruction. The transmitter is

responsible for all message sending activities, including address resolution, via

handling, and the actual message sending. The application can get the

transmitter from the transaction in the

RvSipTransactionFinalDestResolvedEv(). Using the Transmitter API, the

application can manipulate the DNS list before the message is sent. For more

information see the Working with Transmitters chapter.

TRANSACTION

ONTROL

The following API functions provide transaction control:

RvSipTransactionMake()

After creating a transaction, you can use this function to set the To, From and

CSeq parameters in the transaction and send a request with a specified method

and a given Request-URI. All parameters given to this function are in textual

format.

RvSipTransactionRequest()

After creating a transaction and setting the To and From headers and CSeq

sequence number, you can use this function for generating and sending a request

with a specified method and a given Request-URI.