[SIPForum-discussion] A question on SIP Registration Interval

[Andrew Yu]

Hi Vijay & Onur,

My appreciation for your kind response.

Dear Members,

Actually, I'm facing a problem where the sbc reduces the requested 
expiration interval by 1sec until the UA expiration interval reaches 1 
and deregister itself  at expiration interval at 0. The problem surfaced 
after a software upgrade was done on the sbc, the vendor insist that 
there was nothing wrong and the UA should re-register itself based on 
the configured re-register expiration interval of the UA. Am I 
misunderstanding something? The weirdest thing is that this does not 
affect linksys devices like PAP2. They just re-register itself at its 
own pre-configured value.

My appreciation if any nextone & cisco/linksys trained engineers could 
response to my questions. The sbc is from nextone. Thanks alot!

User Datagram Protocol, Src Port: 5698 (5698), Dst Port: 5060 (5060)
Session Initiation Protocol
    Request-Line: REGISTER sip:sip.abc.com SIP/2.0
        Method: REGISTER
        [Resent Packet: False]
    Message Header
        Via: SIP/2.0/UDP 
10.0.0.130:5698;branch=z9hG4bK0a0000825698-1470;rport
        From: sip:12345678 at sip.abc.com;tag=0A0000821642-805261B80
        To: sip:12345678 at sip.abc.com
        Call-ID: 1805261b82954 at a000082
        CSeq: 72 REGISTER
        User-Agent: SIP-6328-2Re-v8.0.3-12345678/v2.0 Enabled
        Contact: "12345678"<sip:12345678 at 10.0.0.130:5698>
        Expires: 2
        Max-Forwards: 70
        Content-Length: 0

User Datagram Protocol, Src Port: 5060 (5060), Dst Port: 5698 (5698)
Session Initiation Protocol
    Status-Line: SIP/2.0 200 OK
        Status-Code: 200
        [Resent Packet: False]
    Message Header
        Via: SIP/2.0/UDP 
10.0.0.130:5698;received=210.24.99.168;branch=z9hG4bK0a0000825698-1470;rport
        From: <sip:12345678 at sip.abc.com>;tag=0A0000821642-805261B80
        To: <sip:12345678 at sip.abc.com>
        Call-ID: 1805261b82954 at a000082
        CSeq: 72 REGISTER
        Expires: 1
        Contact: "12345678" <sip:68267691 at 10.0.0.130:5698>
        Content-Length: 0

-- 
Cheers,

Asiatel Singapore Pte Ltd
Andrew Yu

19 Jalan Kilang Barat
#06-01, Acetech Centre
Singapore 159361

Tel: +65 6271 8233
Fax: +65 6274 4266


vijay sukumaran nair wrote:
> Hi,
>  
> If you get expire time as 30 seconds from registrar it means that 
> after 30 seconds you will loose registration. So you must send 
> reregister request within 30 seconds. Yes the UA should reset the 
> expire time depend upon the response. Please discard this reply if i 
> am wrong.
>  


Onur Cinar wrote:
>
> Hi Andrew,
>
> Yes, that is the case, your UA should obey the registrar's decision. 
> Based on your example, the registrar will keep your registration for 
> 30 seconds, and then it will clean it from its database. So for 
> example, if your UA receives an INVITE at 45 seconds then the calling 
> party will get a 404 although your UA is still running. So you should 
> register in every 30 seconds instead of 60.
>
> Based on my experience, in your UA, make sure to register a little 
> earlier than 30 seconds. I'm mostly registering 5-10 seconds earlier 
> to make sure that my registration won't expire due to some unexpected 
> application side/network delays.
>
> Best regards,
>
> -onur
>
> --
> Visit Nuvoiz.com <http://Nuvoiz.com> for our SoftPhone Soltutions
> A. Onur Cinar - Senior Software Engineer
> T: 1.408.454.6138 F: 1.408.754.6230
> 1973 Landings Drive, Mountain View, CA 94043 USA
>
> On 6/13/07, *Andrew Yu* <andrew at asiatel.com.sg 
> <mailto:andrew at asiatel.com.sg>> wrote:
>
>     Dear members,
>
>     I'll like to know exactly how SIP registration interval is implemented
>     by the RFC.
>
>     When UA send register request with expires 60 and registrar return 200
>     OK but with expires 30, does this mean the next re-register sent
>     by the
>     UA will be sent at expiration interval of 30? What will happen if I've
>     configured the endpoint to re-register every 60s, does this mean that
>     the configured setting will be over-ride by the registrar? Thank you.
>
>     --
>     Cheers,
>
>     Asiatel Singapore Pte Ltd
>     Andrew Yu
>
>     19 Jalan Kilang Barat
>     #06-01, Acetech Centre
>     Singapore 159361
>
>     Tel: +65 6271 8233
>     Fax: +65 6274 4266
>
>
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