SIP in higher education

[Christian Schlatter <>]

Deke Kassabian wrote:
...
> > > http://www.jabber.com/index.cgi?CONTENT_ID=619
>
> Christian Schlatter 
> <>
>  wrote:
> > This article suggests that SIP should be used for voice/video and
> > XMPP for IM&P. I see the following problems with this approach:
> >
> > - SIP and XMPP use different address formats, which would introduce
> > the hassle of having one address for voice/video and one for IM&P
>
> Yes, I certainly agree that that doesn't seem ideal.
>
> > - clients would have to implement two RTC stacks, achieving
> > interoperability between implementations would be more difficult
>
> Another good point.  I guess that means a developer that wants to 
> provide a client with an integrated experience based on XMPP IM&P and 
> SIP voice would, essentially, be writing two clients with one GUI. Is 
> that about right?

Yes, that is also how I see it. Adding a SIP stack to an XMPP client 
would enable a user to click on a buddy list entry to call the 
respective buddy via SIP. Of course this only would work as long as 
there would be a mapping between XMPP and SIP addresses available to the 
client. Another possibility would be to deploy a SIP proxy (or redirect 
server) that handles XMPP-to-SIP address translation.

> > - SIP and XMPP use their own authentication protocols, so there
> > would be
> > the need for single sign-on (same username/pwd for SIP/XMPP)
>
> Is it reasonable to think of this as similar to my mail user agent 
> having to authenticate to smtp servers, imap servers, and ldap servers? 
> In that case, authentication may involve 1, 2 or 3 servers and perhaps 
> as many sets of credentials.  It makes for some config and UA 
> complexity, to be sure.  But generally, it is manageable.
>
> Is this similar?

That's an interesting comparison, and yes it's similar. An XMPP/SIP 
client would need

XMPP server
XMPP username/pwd
SIP username/pwd

(STUN/TURN server)
(outgoing SIP proxy)


Christian