\begin{thebibliography}{1}

\bibitem{rfc2974}
M.~Handley, C.~Perkins, and E.~Whelan, \htmladdnormallink{``Session
  announcement protocol,''}{http://www.rfc-editor.org/rfc/rfc2974.txt} RFC
  2974, Internet Engineering Task Force, Oct. 2000.

\bibitem{rfc3261}
J.~Rosenberg, H.~Schulzrinne, G.~Camarillo, A.~Johnston, J.~Peterson,
  R.~Sparks, M.~Handley, and E.~Schooler, \htmladdnormallink{``{SIP:} session
  initiation protocol,''}{http://www.rfc-editor.org/rfc/rfc3261.txt} RFC 3261,
  Internet Engineering Task Force, June 2002.

\bibitem{rfc2326}
H.~Schulzrinne, A.~Rao, and R.~Lanphier, \htmladdnormallink{``Real time
  streaming protocol {(RTSP)},''}{http://www.rfc-editor.org/rfc/rfc2326.txt}
  RFC 2326, Internet Engineering Task Force, Apr. 1998.

\bibitem{rfc2833}
H.~Schulzrinne and S.~Petrack, \htmladdnormallink{``{RTP} payload for {DTMF}
  digits, telephony tones and telephony
  signals,''}{http://www.rfc-editor.org/rfc/rfc2833.txt} RFC 2833, Internet
  Engineering Task Force, May 2000.

\bibitem{rfc2543}
M.~Handley, H.~Schulzrinne, E.~Schooler, and J.~Rosenberg,
  \htmladdnormallink{``{SIP:} session initiation
  protocol,''}{http://www.rfc-editor.org/rfc/rfc2543.txt} RFC 2543, Internet
  Engineering Task Force, Mar. 1999.

\end{thebibliography}
