On Tue, Oct 12, 2010 at 11:36 AM, Iñaki Baz Castillo <i...@aliax.net> wrote: > 2010/10/12 M. Ranganathan <mra...@gmail.com>: > >> 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/SIMPLE is over engineered for the task of Instant Messaging. I have not seen any major deployments of SIP/SIMPLE. The only reason why one may want to use SIP/SIMPLE in preference to XMPP would be if one wanted to start an IM session in a SIP session that one has opened for some other purpose such as a voice/video call. XMPP makes much more sense for IM. XMPP and SIP are fairly easy to combine using third party call control. -- M. Ranganathan _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
