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

Working with Transmitters 213
Transmitter API
Outbound Address
An address of an outbound proxy that the transmitter should use. The outbound
address is used only if the transmitter is sending a Request message. In this case,
the transmitter will use the outbound address as a remote address and the
Request-URI will be ignored. The outbound address of the transmitter is
ignored if the request contains a Route header, or if the
RvSipTransmitterSetIgnoreOutboundProxyFlag() function was called.
Destination Address
The destination address is the final address (IP, port and transport) that the
transmitter will use for sending the message. The destination address is
calculated in the address resolution process, which takes into account the
existence of outbound address, Route headers and other transmitter parameters.
The application can get the destination address only in the
FINAL_DEST_RESOLVED state of the transmitter that indicates that the
address resolution process has completed. The application can set the
destination address and, in this case, this address will be used and the
transmitter will not perform address resolution.
Persistency Definition and Used Connection
When working with TCP or TLS, the application can instruct the transmitter to
try to locate a suitable open connection in the connection hash before
constructing a new connection. The application can also supply the transmitter
with a connection that the transmitter may use. For more information on
persistency level and Persistent Connection API functions, see Persistent
Connection Handling of the Working with the Transport Layer chapter.
Current State
Represents the state of the transmitter in the message sending process. You can
only access the state parameter with a Get function and it is not modifiable.
DNS List
A transmitter always holds a DNS list object. The DNS list object holds the
answers from the DNS server and is updated in the address resolution process.
The application can manipulate the list using the DNS List API. For more
information on the DNS List API see the Working with DNS chapter.