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

212 HP-UX C SIP Stack Programmer’s Guide

Working With Handles

TRANSMITTER

A transmitter is capable of sending a single SIP message, request or response.

The application should supply the message to the transmitter and the transmitter

will be responsible for all message sending activities, including address

resolution and DNS, connection handling, Via header handling and the actual

message sending.

A transmitter is a stateful object that can assume any state from a set defined in

the Transmitter API. The Transmitter state machine indicates the progress and

result of the message sending process.

TRANSMITTER MANAGER

The TransmitterMgr manages the collection of transmitters and is mainly used

for creating new transmitters.

WORKING WITH

ANDLES

All transmitters and the TransmitterMgr are identified using handles. You must

supply these handles when using the Transmitter API.

RvSipTransmitterMgrHandle defines the TransmitterMgr handle. You receive

this handle by calling RvSipStackGetTransmitterMgrHandle().

RvSipTransmitterHandle defines a transmitter handle. You receive the

Transmitter handle when creating a transmitter with

RvSipTransmitterMgrCreateTransmitter().

TRANSMITTER API The Transmitter API contains a set of functions and function callbacks that

allow you to set or examine transmitter parameters and to control transmitter

functionality.

TRANSMITTER

ARAMETERS

You can set or examine transmitter parameters via transmitter Set and Get API

functions. The following parameters are available:

Local Address and Current Local Address

The Local Address defines the address from where the message will be sent (the

network card). This is also the address that will be placed in the top Via header

of a Request message. If the local address is not set, the transmitter will use a

default local address according to the SIP Stack configuration. A local address

can be configured for each address and transport type. The Current Local

Address is the address that is actually used for sending the message.