[Serusers] call recording app

[Stefan Sayer]

Hello Mihaly,

Mihaly Zachar wrote:
> Hi all,
> 
> I got a job now, I need to build a call recording application, what 
> stores the rtp streams of the calls, what routed to the application.
> 
> There is an existing routing logic (special sip proxy) what decides if 
> the call should be recorded or not. If the call needs to be recorded, 
> this proxy will route the call to this recorder application. This app 
> needs to send through the call to the next sip hop, but it must store 
> the RTP streams on the fly.
> 
> What we have now:
> - we have our own rtpproxy, we can modify it easily if we need to store 
> the streams.
> - we have our own B2BUA what controls the rtpproxy
> 
> I just wondering if we can use SER + SEMS for this, or should we build 
> our own system ? What should be the most effective way ?
> Can it be done with SEMS easily ?

with SEMS you can easily build an application that will decode the RTP, 
save as wav file, and encode to the other call leg, possibly transcoding 
the call. An example for such a type of application is 'jukecall':
http://ftp.iptel.org/pub/sems/doc/current/ModuleDoc_jukecall.html
you'd only need to remove the ivr functionality, and tweak it a little 
so that audio is both relayed and saved to file.

if on the other hand you need to do (il)legal interception type of 
application that will relay and save the RTP without doing anything with 
it, I think its simpler done with modified rtpproxy; afair such 
functionality is already in part implemented, or at least easy to 
implement.

the difference is that SEMS has two independent calls (dialogs, 
sessions) for each leg; both legs are negotiated independently and only 
the (decoded) audio is connected between the two, and SEMS does the 
whole decoding, buffering, PLC etc.

Alternatively you could also modify the SEMS B2BUA to fix the SDP and 
relay RTP, but for this type of application I'd say it's probably easier 
to use rtpproxy.

for further SEMS related tips and implementation hints I'd suggest to 
move the discussion to semsdev mailing list 
(http://lists.iptel.org/mailman/listinfo/semsdev).

hth
Stefan

> 
> Thanks for the suggestions, recommendations.
> 
> 
> Misi
> _______________________________________________
> Serusers mailing list
> Serusers at lists.iptel.org
> http://lists.iptel.org/mailman/listinfo/serusers

-- 
Stefan Sayer
VoIP Services

stefan.sayer at iptego.com
www.iptego.com

iptego GmbH
Am Borsigturm 40
13507 Berlin
Germany

Amtsgericht Charlottenburg, HRB 101010
Geschaeftsfuehrer: Alexander Hoffmann