Opensips has mid-registrar module. It's a method of forwarding registration data to another registrar (usually with a much higher expiration). The idea is to handle high volumes of registrations at opensips and only forward the registration data to another registrar when the data changes. Kamailio doesn't have a mid-registrar module, and IMO, for good reason. The concept of a mid-registrar doesn't make a lot of sense to me as there are much better ways to scale registration data without forwarding REGISTER packets to other registrars.

On Thu, Dec 17, 2020, 7:41 PM Alex Balashov abalashov@evaristesys.com wrote:

It would probably help if you could state exactly what it is that you are trying to achieve. The term "mid-registrar" encompasses a fairly large category of conceivable configurations, though all of them have in common, I suppose, the quality of not passing through registrations upstream in a 1:1 fashion.

On 12/17/20 9:38 PM, moisesynfante wrote:

...

Hello,

I'm a newbie when it comes to Kamailio and I would like to know if

there's a

...

working example of a Mid-Registrar implementation. I read on other posts that the UAC module can be used to achieve this but, honestly, I don't understand how. If any of you could provide some path I could follow I

would

...

be very thankful.

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Hello,

the mid registrar can be done with current kamailio. Practically there are two scenarios:

1) the mid registrar is aware of the passwords for end users, in that case, practically it is just uac module with uacreg database table from kamailio to registrar server:

* https://www.kamailio.org/docs/modules/devel/modules/uac.html#idm650

With options for fine tuning using the functions to enable/disable uacreg records based on registration/unregistration from end points:

* https://www.kamailio.org/docs/modules/devel/modules/uac.html#uac.f.uac_reg_e...

On the end point side, the registrar+usrloc are used as usual

2) the mid registrar is agnostic of username and passwords, it relies on the IP of the first (authenticated by registrar) REGISTER for subsequent registrations of the endpoint -- in this case there was a recent discussion on this mailing list where I described how it can be done:

* https://lists.kamailio.org/pipermail/sr-users/2020-October/110779.html

* https://lists.kamailio.org/pipermail/sr-users/2020-October/110782.html

Looking at the other messages in the thread can be also useful, just get the subject from the above two links and spot the corresponding thread at:

* https://lists.kamailio.org/pipermail/sr-users/2020-October/thread.html#start

The registrar+usrloc can still be used, or not, a matter of what main registrar can do.

So far I needed 1) and works like a charm, providing a lot of flexibility when needing to offload traffic of a system in the same operator. The 2) may look a bit like complex config oriented, but it is not really much.

Considering the two variants available, I think Kamailio offers all needed for what people refer as mid-registrar. If people find cases that they think cannot be covered, just write here and I can try to assist further.

Cheers, Daniel

On 19.12.20 05:13, Alex Balashov wrote:

On 12/18/20 9:05 PM, E. Schmidbauer wrote:

...

Kamailio doesn't have a mid-registrar module, and IMO, for good reason. The concept of a mid-registrar doesn't make a lot of sense to me as there are much better ways to scale registration data without forwarding REGISTER packets to other registrars.

I would strongly agree with that. Nevertheless, the concept of a "condom" to protect vulnerable and poorly-performing commercial registrars from high registration volumes has a lot of currency and steady demand.

The Other Project is not very purist, and is good at packaging and marketing solutions which cater to specific concepts users seem to be infatuated with.

“If I had asked people what they wanted, they would     have said faster horses.” -- Henry Ford

-- Alex

--  Alex Balashov | Principal | Evariste Systems LLC

Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free) Web: http://www.evaristesys.com/, http://www.csrpswitch.com/

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On 12/21/20 3:25 PM, moisesynfante wrote:

Thank you for your answer.

I'm going for the second scenario. I will try the solutions provided in the links and let you know if I made it work!

I posted an example built off the edge proxy config. Remember, many ways to approach this and many things to consider for security before going to a prod environment.

This would be an example of a simple pass-through and then keeping regs to the kamailio at 60 sec while keeping the pass-through to the registrar at an hour (or what they provide as an expire).

https://github.com/fredposner/scripts/blob/master/kamailio/mid-registrar.cfg

-- fred

Fred Posner fred@palner.com https://www.palner.com