[OpenSIPS-Users] OpenSIPS 1.5.3, Load balancer module and open transactions

Bogdan-Andrei Iancu bogdan at voice-system.ro
Mon Dec 6 12:04:39 CET 2010


Hi Gavin,

Do you think it will be helpful for you to "see" (from OpenSIPS) which 
are the these ghost calls ? (I can describe a procedure to get such a 
listing).

Now, about what to do to prevent...More or less is about detecting so 
called ghost calls....and you have several options:

    1) callee/caller specific - if you are in control of one to the end 
points (like you do LB over a bunch of Asterisk servers) :
            A) most of the media devices (PBX, GW, etc) implements media 
timeout - if no RTP is recevied, they fire a BYE, so OpenSIPS will 
receive this BYE and free the call
            B) as A), but using signalling, SST (when the call goes via 
opensips, force SST on callee side). The detection will be done by the 
media server, which will send a BYE

    2) opensips specific - as LB in the middle, you can check the health 
of the dialog by:
             A) media level - both RTPproxy and mediaproxy offers RTP 
timeout events (but this approach will require media relaying for all calls)
             B) signalling level - opensips cannot do much here at the 
moment (like generating in dialog request for probing purposes)



Regards,
Bogdan

Gavin Henry wrote:
> On 5 December 2010 01:07, Advantia VoIP Systems <info at advantia.ca> wrote:
>   
>> Can you verify that a BYE is sent on one UAC and and received on the other?
>>     
>
> We're checking. It looks like it's the technical testing calls as part
> of the ITSPA Awards 2011 - http://www.itspaawards.org.uk/
>
> We've got traces on as we speak. Even so, how can we handle not
> receiving BYEs on the lb? We're open to DOS, if we get lots of these
> our LBs will fill up. We have pike and ratelimit on anyway.
>
> Thanks.
>
>   


-- 
Bogdan-Andrei Iancu
OpenSIPS Bootcamp
15 - 19 November 2010, Edison, New Jersey, USA
www.voice-system.ro




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