[Serusers] Registration Timeout

Girish gr_sh2003 at yahoo.com
Tue Nov 16 15:50:00 CET 2004


Hi,

--- Jan Janak <jan at iptel.org> wrote:

> One small note to the topic. Registrar can shorten the expires value but
> must not extend it. I made a mistake while implementing min_expires
> parameter, the parameter would extend the expiration interval, but the
> registrar should reject such a registration instead. This is what
> RFC3261 says and I will change the registrar to reject such
> registrations later.

One question regarding the registration expiry. I tested the append_to_reply() with Polycom IP500
phone, which sends an 'Expires:3600' header. It was replaced with 'Expires:120'. Now the '200 OK'
has an Expires header with 120 as the value, and a contact header with expires=3600 parameter.
Please see the ngrep trace attached. As far as i understand, the registrar should (in most cases)
accept the expires value in the REGISTER request. But here the reply is transmitted with 2
different parameters. 

Question: Can this be allowed? Can a reply have 2 different expires values?

No problems found in the working of phone though. Polycom accepted 120 as the expires, which again
i beleive is wrong. I think expires parameter should be given priority. Right?


----------------------------------------
REGISTER sip:XXX.XXX.XXX.XXX:5060 SIP/2.0.
Via: SIP/2.0/UDP 192.168.254.116;branch=z9hG4bK79970c8634833F95.
From: "Girish" <sip:girish-testacc-com at XXX.XXX.XXX.XXX>;tag=A05656C2-24685943.
To: <sip:girish-testacc-com at XXX.XXX.XXX.XXX>.
CSeq: 5 REGISTER.
Call-ID: c80027a6-d7be6994-fae0d0b5 at 192.168.254.116.
Contact: <sip:girish-testacc-com at 192.168.254.116>;methods="INVITE, ACK, BYE, CANCEL, OPTIONS,
INFO, MESSAGE, SUBSCRIBE, NOTIFY, PRACK, UPDATE, REFER".
User-Agent: PolycomSoundPointIP-SPIP_500-UA/1.3.1.
Max-Forwards: 70.
Expires: 3600.
Content-Length: 0.
.
 
 
SIP/2.0 200 OK.
Via: SIP/2.0/UDP 192.168.254.116;branch=z9hG4bK79970c8634833F95;rport=65168;received=XX.XXX.XX.XX.
From: "Girish" <sip:girish-testacc-com at XXX.XXX.XXX.XXX>;tag=A05656C2-24685943.
To: <sip:girish-testacc-com at XXX.XXX.XXX.XXX>;tag=b27e1a1d33761e85846fc98f5f3a7e58.16fd.
CSeq: 5 REGISTER.
Call-ID: c80027a6-d7be6994-fae0d0b5 at 192.168.254.116.
Expires: 120.
Contact: <sip:girish-testacc-com at XX.XXX.XX.XX:65168>;q=0.00;expires=3600.
Server: Sip EXpress router (0.8.14 (i386/linux)).
Content-Length: 0.
Warning: 392 XXX.XXX.XXX.XXX:5060 "Noisy feedback tells:  pid=7754 req_src_ip=XX.XXX.XX.XX
req_src_port=65168 in_uri=sip:XXX.XXX.XXX.XXX:5060 out_uri=sip:XXX.XXX.XXX.XXX:5060 via_cnt==1".
--------------------------------

TIA & Regards,

=====
Girish Gopinath  <gr_sh2003 at yahoo.com>


		
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