[standards-jig] TINS and associated subjects

CORVOYSIER David FTRD/DMI/REN david.corvoysier at rd.francetelecom.com
Mon Jan 12 15:40:38 UTC 2004


I've been involved in a project in 2003 that aimed at providing
VoIP communications between XMPP users and between XMPP and SIP users.

We used TINS to establish voice calls between XMPP users, and a gateway 
to translate TINS into SIP to establish calls between an XMPP and a SIP

We had previously (in 2002) implemented a "rough" XMPP voice client
using only jabber:iq:oob,
but we needed to interoperate with SIP user agents.
We decided to go for TINS because we thought it would help us designing
a gateway
to the SIP realm (knowing TINS uses SDPng). 

The results of the project are mitigated:

The good point:

We succeeded in establishing voice calls between two of our XMPP
between our XMPP client and various SIP user agents, and even between
our XMPP
client and standard phones through a SIP PSTN gateway (Yippee !).

The bad points:

1. Using TINS added more complexity to our clients than we thought, for
added value compared to the jabber:iq:oob solution (we don't use that
many options). 

2. Using TINS didn't help us building our gateway: SDPng to SDP mapping
was painful 
enough, and the mapping of all SIP routing/session/transaction/timer
mechanisms to XMPP
was a nightmare (I praise jeremie miller for not having based jabber on
UDP !).

3. To fully interoperate with the SIP world, and especially with phones,
we realized we
would have to add more and more stanzas to TINS, to the extent that we
would completely 
reinvent SIP (PRACK messages needed for interaction with telephony
gateways are an example).

4. SIP is by far not mature in all its implementations, and we had to
dedicate our gateway to
our target SIP equipments (DynamicSoft proxy, Alcatel proxy, Lucent PSTN
gateway): an interface
with other equipments may require additional developments, and may be
incompatible with the existing ones.

5. SDPng is still in its early definition stages. We will be stuck to
the SDPng to SDP mapping for a while ...

6. A brief study showed us that it would also be a pain to add SIMPLE
support to our gateway.

So, as far as our project is concerned, we are now considering to drop
TINS and switch to a dual XMPP/SIP
architecture, because we would rather rely on a SIP stack than embed
anything in XMPP to later translate it to SIP.

Even if the SIP interoperability was not so important to us, I think we
would nevertheless drop TINS and go back to
our jabber:iq:oob solution because it's not worth the complexity it

Now, regarding the SIMPLE interface, I think the way SER did it is the
right way to go: they added a small XMPP module to an 
existing SIMPLE server. Our experience with SIP and XMPP has showed us
that the complexity is more on the SIP side, so if you
can rely on an existing server, it saves us the pain of implementing the
whole "consistency mechanisms" of SIP.

My two cents on that very tricky subject ...


-----Message d'origine-----
De : Yann Klis [mailto:yklis at kaliasys.com]
Envoye : lundi 12 janvier 2004 15:11
A : standards-jig at jabber.org
Objet : [standards-jig] TINS and associated subjects


First, sorry for bothering you with this subject but I didn't found
another mailling list where I can discuss the below points. Excuse me if
it's not the right place.

I saw that VoIP integration (and more generally Videoconferencing
integration) was heavily discuss during year 2003 among various
Jabber.org hosted mailing list, and even a JEP was published (TINS) to
cover this topic.

However, is there really any will to develop the Jabber
protocol/framework to answer this matter ?
I mean, the JEP TINS is nearly 1 year old, but is there any ongoing work
on it? If yes, where can I find this information?

Moreover, is there any attempt to be more interoperable with SIP/SIMPLE
on the Jabber side ? I mean, the only attempt that I'm aware of is the
SER gateway SIMPLE2Jabber.

Finally, is there a known place where I can find more information on
that topic ?

Thanks a lot in advance!


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