2010/10/12 M. Ranganathan <[email protected]>: > But let me ask >> you a question: Do you know XMPP protocol? There are hundreds of >> *good* XMPP implementations "available in internet" licensed as free >> software, and most of them interoperate very well with each other. > > > XMPP is much simpler than SIP and it does much less. When you start > putting in codec renegotiation routing and call transfers and such > into the picture, it starts to look a lot like an XML version of SIP. > SIP is complicated because it can do a LOT.
Sure, I know it. But now take a look to presence specification in both XMPP and SIP. XMPP presence works. SIP presence is the *worst* design in the world (painful XCAP and XML document management???). And even worse, nobody knows what exactly to implement as IETF did an uncomplete set of specifications. >> So, perhaps "internet people" coding XMPP stuff are better than >> "internet people" coding SIP stuff? Or *perhaps* SIP is more much >> difficult and complex to implement than XMPP? Or perhaps XMPP is a toy >> and doesn't scale well as SIP does? (if so we should tell Google and >> Facebook that they must change their IM protocol ASAP). > > > XMPP does less with the screwy scenarios. There, as yet no XMPP > business phone and there is a good reason for that. Because XMPP doesn't implement voice yet (well, it does but it's not widely implemented). > Perhaps there will soon be one, given google and facebook is in the > game. Then XMPP will start resembling SIP ( albeit in XML). SIP is good for voice. XMPP is good for presence /IM. When XMPP comes to voice it becomes complex (XML version of SIP). I agree. Then when SIP comes to presence it should be easy and robust as XMPP, right? For sure this is not true --> bad design, the worst and more stupid design in the world: SIMPLE/XCAP. > Then you can complain about how complex XMPP is..... I think you understood wrong my previous mail. Let me show an example: - In XMPP if a device publishes "available" presence status it means that it is reachable (in SIP terminology we'd say "it is registered"). So it's impossible to publish "available" without being reachable, the server imposes this restriction. - In SIP this is not true. An UA can publish "available" while it is not registered (not reachable). Of course I mean "available" from SIP point of view, I don't care the stupid IETF vision of "available on mail". SIP allows very exotic escenarios as external presence user agents publishing information in behalf of the users, but when coming to 99% of cases (a simple user's device that makes/receives calls and publishes presence) SIP protocol gets too much complex. > SIP has been successful. It does not copulate nor can anybody copulate > with it. Those that try to copulate with it should seek a more > fulfilling love life. I prefer to ignore this phrase. Cheers. -- Iñaki Baz Castillo <[email protected]> _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
