Hi Stephan,

It appears that both the messages are valid syntatically. 
Since absense of port in a sip-URI is assmed to mean 5060 and absence of
transport parameter is assumed to be UDP, the AOR in REGISTER and 200 OK
do match. In my opinion, UA should have found the matching AOR in
contact header valid for 360 seconds. 
To be frank I have experience this matching of AOR with and with :5060 a
number of times.


regards
Rayees


-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Stephan
Steiner
Sent: Friday, May 18, 2007 3:54 PM
To: [email protected]
Subject: [Sip-implementors] Contact matching in registration

Hi

I'm having a problem registering my latest UA (Nokia E65) to my own
proxy (Linksys SPA9000). The proxy sends a 200 OK and lists the binding
in its status page, and routes calls, but the UA never accepts the 200
OK and keeps on sending REGISTER messages. I looked through the message
exchange, and at first found nothing out of the ordinary. Upon further
inspection, I then came across a discrepancy in the Contact field of the
REGISTER message and the reply.

Here's the field from the REGISTER

Contact: <sip:[EMAIL PROTECTED];transport=UDP>;expires=3600

And the reply

Contact: sip:[EMAIL PROTECTED]:5060;expires=360

Then I went into the RFC to see if I could figure out whether this is
allowable or not. What initially struck me is the lack of the <>
brackets in the response, but reading through 20.10 makes me thing this
is permissible in this case as there's no display name, and the
addr-spec contains no comma, question mark or semicolon.

However, section 19.1.4 mentions that an URI without the port does not
match a URI that includes the port, even if that port is the default
5060 for UDP.

Now according to 10.4, when creating a new binding, the UA should go
through the URIs in the register reply, and apply the URI matching rule
from 19.1.4 and once it has located the binding it wanted to create,
update the registration timer with the expiration time for the binding
in question.

Since sip:[EMAIL PROTECTED]:5060 does not match
<sip:[EMAIL PROTECTED];transport=UDP> (the transport is ignored, and I
think the missing <> do not matter, but the port is the problem), the UA
doesn't find the binding it is looking for, thus assumes the creation of
the binding has failed, and continues to send register messages.

I'm wondering whether anyone could confirm that my reasoning is correct
or point out any flaws. For your reference, I'm also pasting the entire
REGISTER and reply messages in the hope that if there's something I'm
missing, somebody more experienced then me could figure it out.

REGISTER sip:192.168.1.4:6060;transport=UDP SIP/2.0
Route: <sip:192.168.1.4:6060;lr;transport=UDP>
Via: SIP/2.0/UDP
192.168.1.124:5060;branch=z9hG4bKu43hooi1d9hc6ca74fs0t0b;rport
From: <sip:[EMAIL PROTECTED]>;tag=nvohoonl3hhc7hul4fs0
To: <sip:[EMAIL PROTECTED]>
Contact: <sip:[EMAIL PROTECTED];transport=UDP>;expires=3600
CSeq: 875 REGISTER
Call-ID: nqUsoFTNoIffFOfU3L2NZS9vlyUUzW
Supported: sec-agree
User-Agent: Nokia RM-208 1.0633.18.01
Max-Forwards: 70
Content-Length: 0

SIP/2.0 200 OK
To: <sip:[EMAIL PROTECTED]>;tag=60b7acd9-0
From: <sip:[EMAIL PROTECTED]>;tag=nvohoonl3hhc7hul4fs0
Call-ID: nqUsoFTNoIffFOfU3L2NZS9vlyUUzW
CSeq: 875 REGISTER
Via: SIP/2.0/UDP
192.168.1.124:5060;branch=z9hG4bKu43hooi1d9hc6ca74fs0t0b
Contact: sip:[EMAIL PROTECTED]:5060;expires=360
Server: Linksys/SPA9000-5.1.7
Allow-Events: talk, hold, conference
Content-Length: 0
Date: Mon, 13 Apr 2007 22:56:36 PST

Before I forget, the Date field in the reply also violates 20.17 - only
GMT is allowed

Regards
Stephan

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