e," IETF. December 1998. [RFC 2543] M. Handley, H. Schulzrinne, E. Schooler, and J. Rosenberg, "SIP: Session initiation protocol," IETF. March 1999. [RFC 2597] J. Heinanen, F. Baker, W. Weiss, J. Wroclawski. "Assured Forwarding PHB Group," IETF. June 1999. [RFC 2598] V. Jacobson, K. Nichols, K. Poduri. "An Expedited Forwarding PHB," IETF. June 1999. [RFC 2608] E. Guttman, C. Perkins, J. Veizades. "Service Location Protocol, Version 2," IETF. June 1999. References [RFC 2633] B. Ramsdell, "S/MIME Version 3 Message Specification," IETF. June 1999. [RFC 2705] M. Arango, A. Dugan, I. Elliott, C. Huitema, S. Pickett. "Media Gateway Control Protocol (MGCP) Version 1.0," IETF. October 1999. [RFC 2779] M. Day, S. Aggarwal, G. Mohr, J. Vincent. "Instant Messag- ing/Presence Protocol Requirements," IETF. February 2000. [RFC 2848] S. Petrack, L. Conroy. "The PINT Service Protocol: Extensions to SIP and SDP for IP Access to Telephone Call Services," IETF. June 2000. [RFC 2960] R. Stewart, Q. Xie, K. Morneault, C. Sharp, H. Schwarzbauer, T. Taylor, I. Rytina, M. Kalla, L. Zhang, V. Paxson. "Stream Control Transmission Protocol," IETF. October 2000. [RFC 2974] M. Handley, C. Perkins, E. Whelan. "Session Announcement Protocol," IETF. October 2000. [RFC 2976] S. Donovan, "The SIP INFO Method," IETF. October 2000. INDEX Symbols SIP, 192 decomposition, 114 3G mobile systems, 192-193 programming, 113 buddy lists, 199 architecture circuit-switched domains, 193 Internet, TCP/IPprotocol suite, 56 instant messages, 199 IP multimedia domains, 3G mobile IP multimedia domains, 193-194 systems, 194 network domains, 193 PacketCable, 203 packet-switched domains, 193 ARPANET, 45 presence information, 199 assured forwarding, PHBs, 80 roaming user sessions, 197 asynchronous event notification, SIP user registration, 195 extensions, 179 visited domain registration, 196 attenuation of signals, 14 attributes, SDP session descriptions, 85 audio codecs, 14 authentication, 187-189 automatic UA configuration, SIP extensions, 172-173 AC analog phone sys