\section{Open Issues}

\subsection{H.323}

\begin{description}
\item[Problem:] Detailed interaction with H.323 and H.245.

\item[Solution:] Leave to separate document.

\item[Status:] Closed.
\end{description}

\subsection{REGISTER}

\begin{description}

\item[Problem:] How does the UA get a ``personalized'' multicast address
for multicast searches?  It would be helpful if the server could return
an indication of any local search multicast address the user agent is
supposed to listen on.  The server might also want to indicate whether
all outgoing calls should be proxied through the server.  Use of message
bodies for {\REGISTER} requests.

\item[Solution:] Leave for follow-on work.  Possible to use
\header{Location} with 200 response, but already otherwise used to
indicate registrations.

\item[Status:] Closed.
\end{description}

\subsection{Max-Forwards}

\begin{description}
\item[Problem:] Extend \header{Max-Forwards} with a max fan out field. 
[Not really related.] How do you limit fanout for multicast?  What's the
advantage of doing this?

\item[Solution:] Await operational experience as to whether users
can actually set this value to anything meaningful.

\item[Status:] Closed.

\end{description}

\subsection{Cancellation and BYE}
\begin{description}
\item[Problem:] Determine how to cancel
\begin{itemize}
\item searches
\item ringing
\item non-selected end systems
\item calls
\end{itemize} 

\item[Solution:] In spec.

\item[Status:] Closed.

\subsection{IPv6 URLs}

\begin{description}
\item[Problem:] Numeric IPv6 addresses in URLs.
\item[Solution:] None; wait for others to take the lead. Note that this
affects only {\bf numeric} addresses, which should be rarely used.
\item[Status:] Defered.
\end{description}

\end{description}
