Subject: [Sip] Open Issue #197: URLs in OPTIONS

From: Jonathan Rosenberg <[email-masked]>
Date: Thu, 6 Dec 2001 02:16:10 -0500

Issue:

What kind of URLs are allowed in an OPTIONS response?

The right answer depends on the interpretation of the Contact in the OPTIONS
response. Really, Contact has two separate meanings. The one in INVITE and
INVITE-200 are signaling addresses, which always need to be one single SIP
URL. The Contact in 3xx, REGISTER, and REGISTER-200 are alternate names for
a user, which can be non-SIP URLs, and there can be more than one. The
distinction is subtle (and this is why its one header), but I have become
convinced that they are distinct.

Now, which of these two do we want in OPTIONS? If we are trying to obtain a
direct address for signaling for INVITE, then we want the first
interpretation, in which case it needs to be a single SIP URL. If its a set
of alternate names for a user, then it can be multiple non-SIP URLs. 

Discussion:

In most cases, you are not going to be able to signal directly to the
contact anyway, for firewall/nat/policy reasons. Therefore, the more useful
piece of information is the alternate set of names for the user.

Proposal:

Contact in 2xx to OPTIONS has redirect semantics.

-Jonathan R.
---
Jonathan D. Rosenberg, Ph.D.                72 Eagle Rock Ave.
Chief Scientist                             First Floor
dynamicsoft                                 East Hanover, NJ 07936
[email-masked]                     FAX:   (973) 952-5050
http://www.jdrosen.net                      PHONE: (973) 952-5000
http://www.dynamicsoft.com

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---

From: Jonathan Rosenberg <[email-masked]>
Date: Thu, 27 Dec 2001 02:41:23 -0500

There were no comments on this proposal. I will interpret silence as 
acceptance of the proposal. Issue closed.

-Jonathan R.

-- 
Jonathan D. Rosenberg, Ph.D.            72 Eagle Rock Avenue
Chief Scientist                         First Floor
dynamicsoft                             East Hanover, NJ 07936
[email-masked]                 FAX: (973) 952-5050
http://www.jdrosen.net                  PH:  (973) 952-5000
http://www.dynamicsoft.com