[SR-Users] What is the typical network setup for kamailio?

Henning Westerholt hw at kamailio.org
Thu Aug 16 19:12:02 CEST 2018

Am Donnerstag, 16. August 2018, 11:57:03 CEST schrieb Kevin Olbrich:
> I am working successfully with Kamailio in my lab setup where Kamailio is
> the SBC for Asterisk.
> The network layout is looking like this:
> SIP-Phone <== PUBLIC NET ==> Kamailio (SBC) <== PRIVATE NET ==> Asterisk
> <== PUBLIC NET ==> Carrier
> Each public network is reachable from the internet and has a local firewall
> with IP whitelists.
> The internal SIP transactions are UDP-only but for external phones I would
> like to also listen for TCP/TLS.
> For this layout to work with rtpproxy (before we move on to RTPengine), we
> have to enable mhomed in Kamailio.
> We also have some routing issues with packets leaving with the wrong IP via
> rtpproxy (when call between carrier and external phone needs to be bridged).
> Most examples show that Asterisk is deployed on the same network as the
> external interface of Kamailio (-> Asterisk exposed to the public network).
> In our tests, this works much better but I have great security concerns
> because this Asterisk instance itself does not need to be reachable from
> external.
> How do other users deploy Kamailio in front of Asterisk or similar as SBC
> to secure internals?
> There is lot of docs for Kamailio's config but IMHO less for the setup as
> DMZ (SBC) proxy.

Hello Kevin,

this is indeed a common setup to protect asterisk and to have also much 
greater flexibility with regards to balancing and/or SIP message adaptions.

To get some ideas, have a look to the last years conferences available here:


There should be some talks about using Kamailio to in front of asterisk, the 
talk name is usually in the file name.

I think even on this year cluecon Fred Posner did a talk about Kamailio as 
Edge Proxy, and also on astricon there were some talks  about this scenario if 
I remember correctly.

You should also find in the Kamailio World or FOSDEM talks a lot of 
information about this scenario.  You find all the talks available from 
Kamailio World in our youtube channel: 


Best regards,


Henning Westerholt

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