> SIP may have been initially motivated by telephony style applications but it > is a very general and extensible negotiation protocol - it was that aspect > that grabbed my attention when I first heard about Schulzrinne's work on it > several years ago. I think the point really is that SIP is extensible and > may be a very reasonable platform on which to build a wide range of peer to > peer and distributed application control. SIP certainly is extensible, but I strongly suspect that we wouldn't be giving it serious consideration for this use if there weren't already a substantial investment in it from the telephony world. What makes sense for telephone providers (because of that investment) doesn't necessarily make sense for the Internet. SIP should of course be considered, but it shouldn't be assumed as part of the solution path before the WG has even had a chance to consider other, possibly less complex, alternatives. Keith