\section{Authors' Addresses}

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Mark Handley\\
ACIRI\\
electronic mail: {\sf mjh@aciri.org}
\end{flushleft}

\begin{flushleft}
Henning Schulzrinne\\
Dept. of Computer Science\\
Columbia University\\
1214 Amsterdam Avenue\\
New York, NY 10027\\
USA\\
electronic mail: {\sf schulzrinne@cs.columbia.edu}
\end{flushleft}

\begin{flushleft}
Eve Schooler\\
Computer Science Department 256-80\\
California Institute of Technology\\
Pasadena, CA 91125\\
USA\\
electronic mail: {\sf schooler@cs.caltech.edu}
\end{flushleft}

\begin{flushleft}
Jonathan Rosenberg\\
dynamicsoft\\
72 Eagle Rock Ave\\
East Hanover, NJ 07936\\
USA\\
electronic mail: {\sf jdrosen@dynamicsoft.com}
\end{flushleft}
