Hello,
On 10/21/10 11:20 AM, Iñaki Baz Castillo wrote:
2010/10/21 Daniel-Constantin Mierla<mico...@gmail.com>:
I think it is just failure of one model over-complicated, the Presence
Agent.
SIP has also end-to-end presence and it was/is working perfect in most of
the cases.
Hi, I don't agree. SIP end-to-end presence fails when coming to
privacy area as the watcher doens't receive the information from a
server, but from the watched user itself (so the watcher knows if it's
"online" or not). I've tryed end-to-end SIP presence and IMHO is just
a toy.
this kind of privacy is affecting the calls as well, for example. I can
send you a call or other SIP request to discover you are online/offline.
So this is another service that should be applied globally: black-white
lists.
Having a mechanism just for presence is another bad design.
Also, about XMPP and "ent-to-end" presence:
"distributing states" is done by sending<presence> stanzas. XMPP
basic presence (online, offline and text note) works in this way. This
is, a XMPP client gets online and sends<presence> stanza to all its
non-blocked contacts to inform about its presence status.
However, other presence features in XMPP as the avatar, advanced
presence (like the music you are listening now), work with
publish-subscribe mechanism. This mechanism is much more scalable.
Please read this short thread I open in XMPP-IETF about it:
http://www.ietf.org/mail-archive/web/xmpp/current/msg01703.html
This is: publish-subscribe mechanism has also being adopted by XMPP.
So IMHO this mechanism is the most suitable also for SIP, but it must
be improved (the specs and features).
With a model where client and server must develop in parallel you have
always the chicken-egg problem.
While I said that some interaction between endpoint and core network has
to be done (e.g., centralized rooster, hosting avatars, etc), it must be
pretty much content agnostic. When the core network becomes an active
player in the final content delivery of what I send, then innovation is
slowed down considerably.
If you think about very popular solutions for real time communication
out there, the patters is smart endpoint, dummy core network, and in
most of the cases (skype, yahoo), same provider for both sides.
Telephony providers must understand they have to come with services
provided by them in order for me to pay. If they put barriers because
they want to charge the services I am capable alone to do, then I skip them.
Cheers,
Daniel
--
Daniel-Constantin Mierla
http://www.asipto.com
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