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

216 HP-UX C SIP Stack Programmer’s Guide

Transmitter API

 The DNS procedure is a-synchronic, and therefore the send

function may return with success before the message was

actually sent.

 If you wish the transmitter to fix the top Via header of the

message according to the remote party address and transport

types, you should first call the

RvSipTransmitterSetFixViaFlag() function. Otherwise the

transmitter will only fix the via transport and will add the rport

parameter in case it was configured to the SIP Stack. The sent-

by parameter will remain untouched.

 The transmitter copies the message supplied by the application

to the SIP Stack memory. The application is responsible for

destructing the message it supplies to this function.

RvSipTransmitterHoldSending()

Holds all sending activities of the transmitter and moves the transmitter to the

ON_HOLD state. After address resolution is completed and before the message

is sent, the transmitter moves to the FINAL_DEST_RESOLVED state. In this

state, the application can hold the message sending by calling

RvSipTransmitterHoldSending(). If the application wishes, it can change the

remote address at this point using the RvSipTransmitterSetDestAddress()

function and manipulate the rest of the DNS list using the Transport layer API.

If the application wishes the transmitter to use the next element in the list, it can

use the RvSipTransmitterSetDestAddress() function to reset the current

destination address. The transmitter will then repeat the address resolution

process before sending the message. It is the responsibility of the application to

resume the sending of the message using RvSipTransmitterResumeSending().

RvSipTransmitterResumeSending()

Resumes the sending activities of the transmitter. This function can be called

only in the ON_HOLD state of the transmitter. When this function is called, the

transmitter first checks that a destination address exists. If one exists, the

transmitter moves to the READY_FOR_SENDING state and then sends the

message to this address. If there is no a destination address (the user reset the

address by calling RvSipTransmitterSetDestAddress() with NULL values), the

transmitter returns to the RESOLVING_ADDR state and to the address

resolution process.