\section{Usage of SIP with RTP}
\label{sec:rtp}

To send a SIP request to a user that has announced itself through RTCP
messages, the client application {\MAY} follow these steps:
\begin{enumerate}
\item If available, use the SIP-CADDR RTCP SDES element as the SIP-URL.

\item If SIP-CADDR is not available, a client {\MAY} attempt to contact
the user via the CNAME RTCP SDES element.  This is likely to succeed
only during the RTP session.

\item After the RTP session or if the previous step failed, the client
application {\MAY} also attempt the address in the EMAIL RTCP SDES
element.
\end{enumerate}
