[SR-Users] Limiting Registration Contacts

Daniel-Constantin Mierla miconda at gmail.com
Mon Dec 5 14:52:55 CET 2016


Hello,

I didn't try to suggest that what you want won't be useful or rejected
if someone wants to contribute. My explanation was for what exists now.

Also, be aware that you can have one contact per device, which is
feature controlled differently than the max_contacts -- see save()
documentation from registrar module.

Moreover, the usrloc module can delete unreachable contacts (if they
don't respond to OPTIONS keepalives). It can also remove contacts that
have the associated tcp connection closed (if the devices connect
directly to registrar) -- you can implement also your idea of sending
notifications from an edge proxy when a tcp connection is closed (see
tcpops module for the event_route executed in such case).

Cheers,
Daniel


On 05/12/2016 13:33, Colin Morelli wrote:
> Hey Daniel,
>
> This makes sense, thanks for the explanation.
>
> While I can understand why it works the way it does now, I still think
> having an option here would be great. My thought is, whether the
> mobile phone that re-registers every 10 minutes or the desk phone is
> "older," the point is that they're both older than the device which is
> currently trying to register and is unable to. There's also some
> preferential logic you could try to add here - perhaps try to remove
> .invalid contacts first, which are generally used by browsers and
> likely less stable than contacts with an IP address.
>
> All that said, I appreciate the clarification. I believe it's fairly
> trivial to do this with sqlops anyway so it's not a huge deal. I also
> may be able to do something in the edge proxy to automatically send an
> unregister if a websocket connection closes after a register request.
>
> Thanks!
> Colin
> On Mon, Dec 5, 2016 at 6:02 AM Daniel-Constantin Mierla
> <miconda at gmail.com <mailto:miconda at gmail.com>> wrote:
>
>     Hello,
>
>     right now the rule is to reject the registrations that exceed the
>     max_contacts limit. The main reason behind this policy is the
>     registration mechanism in SIP which requires periodic
>     update/refresh but also different expires intervals.
>
>     In this way it's hard to select the "old device". Can be a desktop
>     phone registering every hour and stable connection but also a
>     mobile phone registering every 10 minutes, changing the ip every
>     now and then. By just relying on the oldest registration, the
>     desktop phone is likely the candidate to remove most of the time,
>     but keep other invalid mobile contacts.
>
>     The solution would be to use GRUU (or the instance parameter) for
>     registration contacts. In this way each new registration from a
>     device will replace its own old contact, even if it has a
>     different contact address.
>
>     Cheers,
>     Daniel
>
>
>     On 01/12/2016 23:59, Colin Morelli wrote:
>>     Hey Alex - not sure I'm quite following what you mean. The
>>     bindings are only for web clients. Are you suggesting the clients
>>     themselves de-register? I'd have no problem with that with the
>>     exception of the fact that there's simply no way to guarantee
>>     that happens. It's a race condition between whether the
>>     unregistration can be sent before the browser kills the websocket
>>     connection on refresh.
>>
>>     On Thu, Dec 1, 2016 at 5:57 PM, Alex Balashov
>>     <abalashov at evaristesys.com <mailto:abalashov at evaristesys.com>> wrote:
>>
>>         Wouldn't it be more fruitful to delete and reach old bindings
>>         in such a scenario? Or are these bindings not only for web
>>         clients?
>>
>>         On December 1, 2016 5:54:06 PM EST, Colin Morelli
>>         <colin.morelli at gmail.com <mailto:colin.morelli at gmail.com>> wrote:
>>         >Hey all,
>>         >
>>         >I know Kamailio's registrar module has a max_contacts
>>         parameter that
>>         >will
>>         >limit the number of active contacts for an AOR. However, is
>>         there any
>>         >mechanism to control what happens when that number is hit?
>>         >
>>         >When using a web client where every page refresh registers a new
>>         >contact
>>         >with Kamailio, it would be useful to automatically roll off
>>         the oldest
>>         >registrations and replace to make room for the new ones. I
>>         know this
>>         >can be
>>         >manually accomplished with sqlops, but I was hoping
>>         something like this
>>         >already existed.
>>         >
>>         >Best,
>>         >Colin
>>         >
>>         >
>>         >------------------------------------------------------------------------
>>         >
>>         >_______________________________________________
>>         >SIP Express Router (SER) and Kamailio (OpenSER) - sr-users
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>>         <mailto:sr-users at lists.sip-router.org>
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>>
>>
>>         -- Alex
>>
>>         --
>>         Principal, Evariste Systems LLC (www.evaristesys.com
>>         <http://www.evaristesys.com>)
>>
>>         Sent from my Google Nexus.
>>
>>
>>         _______________________________________________
>>         SIP Express Router (SER) and Kamailio (OpenSER) - sr-users
>>         mailing list
>>         sr-users at lists.sip-router.org
>>         <mailto:sr-users at lists.sip-router.org>
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>>
>>
>>
>>
>>     _______________________________________________
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>
>     -- 
>     Daniel-Constantin Mierla
>     www.twitter.com/miconda <http://www.twitter.com/miconda> -- www.linkedin.com/in/miconda <http://www.linkedin.com/in/miconda>
>     Kamailio World Conference - May 8-10, 2017 - www.kamailioworld.com <http://www.kamailioworld.com>
>
>     _______________________________________________
>     SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing
>     list
>     sr-users at lists.sip-router.org <mailto:sr-users at lists.sip-router.org>
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>

-- 
Daniel-Constantin Mierla
www.twitter.com/miconda -- www.linkedin.com/in/miconda
Kamailio World Conference - May 8-10, 2017 - www.kamailioworld.com

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