ability.org>;tag=2321 From: P. L. Chebychev <sip:chebychev@academy.ru>;tag=4542 Call-ID: 9dkei93vjq1ei3 CSeq: 15 MESSAGE Content-Length: 0 Call Flow Examples MESSAGE sip:chebychev@academy. . ru SIP/2.0 Via SIP/2.0/TCP dist.probablilty.org : 5060 :branch=z9hG4bK4526245 Max-Forwards: 70 To: P. L. Chebychev <sip:chebychev@academy.ru From: M. Poisson <sip:s.possion@dist.probability.org>;tag=14083 Call-ID: lk34452k592520 CSeq: 2321 MESSAGE Allow: ACK, INVITE, CANCEL, BYE, NOTIFY, SUBSCRIBE, MESSAGE Content-Type: text/plain Content-Length: 30 Well, hello there to you, too! M10 SIP/2.0 200 OK Via SIP/2.0/TCP dist.probablilty.org 5060 branch=z9hG4bK4526245;received=24.32. To: P. L. Chebychev <sip:chebychev@academy.ru>;tag=mc3bg5q77wms From: M. Poisson <sip:s.possion@dist.probability.org>;tag=14083 Call-ID: 1k34452k592520 CSeq: 2321 MESSAGE Content-Length 0 References Rosenberg, J., et al., "SIP: Session Initiation Protocol," RFC 3261, 2002. Johnston, A., et al., "Basic SIP Call Flow Examples," IETF Internet-Draft, Work in Pro- gress, April 2003. Johnston, A., et al., "SIP/PSTN Call Flow Examples," IETF Internet-Draft, Work in Pro- gress, April 2003. Schulzrinne, H., and H. Agrawl, "Session Initiation Protocol (SIP)-H.323 Interworking Requirements," IETF Internet-Draft, Work in Progress, February 2003. Future Directions This chapter will discuss some future areas of work in SIP-related working groups in the IETF. Instead of attempting to list and discuss a snapshot of cur- rent activity in the IETF, the reader should gather the information directly from the IETF itself. Table 11.1 lists the charter Web pages for the three most impor- tant SIP working groups: SIP, SIPPING, and SIMPLE. The charter page for each working group lists the deliverables of the group along with RFCs (finished documents) and Internet-Drafts (works in progress). Only Internet-Drafts that have been adopted as official work group items are listed on these Web pages-these are the documents most likely to become RFCs in the near future. The Web page als