Benny Prijono wrote:
>
> Arunachalam Venkatraman wrote:
> >
> > 1.When does it make sense to have multiple Contact headers in a INVITE
> > request? I am trying to imagine scenarios where this would be useful. One
> > possibility is when there are multiple interfaces that you may be reached at
> > but you have no single domain name that translates to these addresses. Seems
> > contrived, though.
> >
>
> I think what the draft is saying is that you can insert not only the
> SIP URL, but also your email or HTTP url. When there happens to be
> multiple SIP URL contacts, then I think the draft is silent about
> this.
The intention is that there is only a single Contact in
INVITEs/200s and that it is a SIP URL. Keeping this simple
guarantees basic interoperability, faster call set up and
easier record routing.
3xx reponses are different. Here you can have multiple Contacts
and non SIP URLs. May be the spec could be more explicit on
this.
> More, I'm quite interested about this quote (in section 6.15,
> Contact):
> "The Contact value SHOULDNOT be cached across calls, as it
> may not represent the most desirable location for a particular
> destination address."
>
> Does it mean I can NOT save the Contact (SIP) URL to my address book?
> (I think yes, I can)
You are better of using the From header to identify SIP
URLs for your address book etc.
> If I can, then can I specify multiple SIP URL in the contact, with
> each of them is completely different address, such as my office SIP
> URL, home SIP URL, my URL registered to other SIP service I found in
> web, etc.?
>
> I think the answer is again yes, I can. The UAS should still be able
> to choose the URL used for this Call-ID, based on the qvalue.
>
> But in any case, the draft should be clear about this.
>
> > 2. If there are multiple Contacts in an INVITE, which of these does the UAS
> > use to copy the name-addr value from, into the Route header?
> >
>
> Choosing only from the SIP URL Contacts, choose one with highest
> qvalue?
Who can say. A good example of why sticking to one SIP URL
in the Contact of INVITEs/200s is the right thing to do.
Cheers,
Neil.
--
Ubiquity Software Corporation, UK http://www.ubiquity.net
_______________________________________________
Sip-implementors mailing list
[EMAIL PROTECTED]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
