[SR-Users] set_advertised_port using pseudovariable

Neven Boric nboric at yx.cl
Tue Aug 7 23:23:50 CEST 2012


Alex Balashov escribió:
> On 08/07/2012 04:34 PM, Neven Boric wrote:
>
>> So, am I missing something or does set_advertised_port actually only
>> accept literal values?
>
> Correct, set_advertised_port does not accept PVs.  There is an entire 
> category of legacy core functions, and some module functions, for 
> which that is true.
>
> There's an ongoing effort to update many of them to use PVs, but it's 
> ... incremental.  :-)
I wonder how hard would it be to do it myself. Just getting to know 
Kamailio as a user, haven't looked at the code yet. Any pointers? 
Hopefully some other function where this was recently implemented, so I 
can browse the commits.
>
> Methodologically speaking, you really, really don't want to run 
> Kamailio behind a NAT as a client, unless the endpoint on the other 
> side of the NAT can deal with it entirely using far-end NAT traversal 
> strategies.
There's this trend here (and I assume elsewhere) of providers offering 
hosted (i.e remote) PBX and installing an "SBC" on customer premises to 
access said PBX. I use quotes for SBC, because, from what I've gathered, 
it can mean different things to different people. In this case, it's a 
device that can be used to access the remote PBX without worring about 
NAT issues, handles security, does SIP normalization, topology hiding, 
maybe encryption, etc. One important feature is survivability, as in 
UACs being able to talk to each other (and maybe do conferences and 
other media stuff, so you also need a media server) in case the remote 
PBX is temporarily inaccessible. I just assumed they are installed 
behind the NAT, because all manufacturers (AudioCodes, Mediatrix and the 
like) mention NAT traversal as an important feature. Also, most of the 
times the clients are SMBs without access (or lacking the knowledge, or 
just hesitant because of security reasons) to configure port forwarding 
on their router.

Are you familiar with this scenario? Would you say I'm wrong in thinking 
these devices are installed behind the NAT? Or that Kamailio is not a 
good choice for this scenario?

Thanks
--
Neven Boric



More information about the sr-users mailing list