.3.1 Authenticaton-Info 6.3.2 Error-Info Contents 6.3.3 Min-Expires 6.3.4 Min-SE 6.3.5 Proxy-Authenticate 6.3.6 Server 6.3.7 Unsupported 6.3.8 Warning 6.3.9 WWW-Authenticate 6.3.10 Message Body Header Fields 6.4.1 Allow 6.4.2 Content-Encoding 6.4.3 Content-Disposition 6.4.4 Content-Language 6.4.5 Content-Length 6.4.6 Content-Type 6.4.7 Expires 6.4.8 MIME-Version References Related Protocols SDP-Session Description Protocol 7.1.1 Protocol Version 7.1.2 Origin 7.1.3 Session Name and Information 7.1.4 7.1.5 E-Mail Address and Phone Number 7.1.6 Connection Data 7.1.7 Bandwidth 7.1.8 Time, Repeat Times, and Time Zones 7.1.9 Encryption Keys 7.1.10 Media Announcements 7.1.11 Attributes 7.1.12 Use of SDP in SIP RTP-Real-Time Transport Protocol RTP Audio Video Profiles PSTN Protocols SIP: Understanding the Session Initiation Protocol 7.4.1 Circuit Associated Signaling 7.4.2 ISUP Signaling 7.4.3 ISDN Signaling SIP for Telephones Universal Plug and Play Protocol References Comparison to H.323 Introduction to H.323 Example of H.323 Versions Comparison 8.4.1 Fundamental Differences 8.4.2 Strengths of Each Protocol Conclusion References Wireless and 3GPP IP Mobility SIP Mobility 3GPP Architecture and SIP 3GPP Header Fields 9.4.1 Service-Route 9.4.2 9.4.3 Other P-Headers Future of SIP and Wireless References Call Flow Examples SIP Call with Authentication, Proxies, and Record-Route SIP Call with Stateless and Stateful Proxies with Called Party Busy SIP to PSTN Call Through Gateway PSTN to SIP Call Through Gateway Contents Parallel Search H.323 to SIP Call 3GPP Wireless Call Flow Call Setup Example with Two Proxies SIP Presence and Instant Message Example References Future Directions SIP, SIPPING, and SIMPLE Working Group Design Teams 11.1.1 SIP and Hearing Impairment Design Team 11.1.2 Conferencing Design Team 11.1.3 Application Interaction Design Team 11.1.4 Emergency Calling Design Team Other SIP Work Areas 11.2.1 Emergency Preparedness 11.2.2 Globally Routable Contact URIs 11.2.3 Service Examples SIP Instant Message and Pres