[Kamailio-Users] Having problems using RTPProxy to bridge internal/external networks

Daniel-Constantin Mierla miconda at gmail.com
Thu Oct 15 19:45:47 CEST 2009


IIRC, I use:

if(dst_ip==private_ip)
       force_rtp_proxy("ocfaei");
 else
       force_rtp_proxy("ocfaie");

rtpproxy started with: -l external_ip/private_ip

Probably is rtpproxy 1.1 -- cannot check right now.

Cheers,
Daniel

On 15.10.2009 19:38 Uhr, Alex Balashov wrote:
> We attempted that formula as well.  The problem is that rtpproxy won't 
> actually forward the packets to the other interface when started in 
> what is supposed to be bridging mode, i.e.
>
>   rtpproxy -F -s udp:xxx.xxx.xxx.xxx:5060 -l outside.ip/inside.ip
>
> I enabled /proc/sys/net/ipv4/ip_forward but it did not help.
>
> Daniel-Constantin Mierla wrote:
>
>> Hello,
>>
>> I have several rtp bridging deployments, I started from alg.cfg
>>
>> http://openser.svn.sourceforge.net/viewvc/openser/trunk/modules/nathelper/examples/alg.cfg?revision=2&view=markup 
>>
>>
>> Cheers,
>> Daniel
>>
>>
>> On 15.10.2009 17:06 Uhr, Örn Arnarson wrote:
>>> Hi Klaus,
>>>
>>> Yes, I have learned that both are not to be used. However, I am unable
>>> to get the SDP to change with the force_rtp_proxy call. Can you see
>>> anything wrong with the way I am calling it? The call is clearly in
>>> effect, as it does change the media addresses, just not to what I need
>>> them to be. Even if I do specify them explicitly in the call.
>>>
>>> Best regards,
>>> Örn
>>>
>>> 2009/10/15 Klaus Darilion <klaus.mailinglists at pernau.at>:
>>>  
>>>> never call both functions. That will not work (you see the result)
>>>>
>>>> when using the correct parameters (flags), force_rtpproxy() should 
>>>> be able
>>>> to fix the SDP correctly
>>>>
>>>> regards
>>>> klaus
>>>>
>>>> Örn Arnarson wrote:
>>>>   
>>>>> Hi Klaus,
>>>>>
>>>>> I've gathered as much; I'm able to bridge between the interfaces, but
>>>>> if I do that, I can't rewrite the SDP properly. I can only rewrite 
>>>>> the
>>>>> SDP by using fix_nated_sdp. If I use fix_nated_sdp and the rtpproxy
>>>>> functions to bridge the call, the SDP gets messed up.
>>>>> E.g. I rewrite the media address with fix_nated_sdp from the public
>>>>> IP, 157.157.x.x to 10.252.1.8, but if I then call the force_rtp_proxy
>>>>> function, it just appends the public IP address directly behind the
>>>>> 10.252.1.8 IP address, so the SDP media address is now
>>>>> 10.252.1.8157.157.x.x.
>>>>>
>>>>> Any ideas?
>>>>>
>>>>> Regards,
>>>>> Örn
>>>>>
>>>>> On Thu, Oct 15, 2009 at 12:30 AM, Klaus Darilion
>>>>> <klaus.mailinglists at pernau.at> wrote:
>>>>>     
>>>>>> I think it is not about offer/answer, but you have to call rtpproxy*
>>>>>> functions with  the proper parameter to activate bridging inside
>>>>>> rtpproxy.
>>>>>>
>>>>>> E.g. there is an (I guess rather old) example for ipv4 to ipv6 
>>>>>> bridging,
>>>>>> but
>>>>>> from the logic it should be similar to v4:v6 bridging:
>>>>>>
>>>>>> http://openser.svn.sourceforge.net/viewvc/openser/trunk/modules/nathelper/examples/4to6.cfg?revision=2&view=markup 
>>>>>>
>>>>>>
>>>>>> Take a look at the i and e flag:
>>>>>> http://kamailio.org/docs/modules/1.5.x/nathelper#id2468157
>>>>>>
>>>>>> regards
>>>>>> klaus
>>>>>>
>>>>>> Joe Hart wrote:
>>>>>>       
>>>>>>> Hi all,
>>>>>>>
>>>>>>> For a project on which I'm currently working, I am having some 
>>>>>>> problems
>>>>>>> figuring out how to correctly configure Kamailio to communicate 
>>>>>>> with RTP
>>>>>>> Proxy in order to send media into and out of a network with 
>>>>>>> private IP
>>>>>>> address ranges.
>>>>>>>
>>>>>>> I have a proxy set up to send the SIP traffic, and all of this is
>>>>>>> working
>>>>>>> fine.  However, I'm having some trouble getting the RTP Proxy 
>>>>>>> set up.
>>>>>>>  Currently, when the call is connected, the offer/answer is made 
>>>>>>> and RTP
>>>>>>> Proxy seems to be taking over, but I'm having trouble getting my 
>>>>>>> audio
>>>>>>> to
>>>>>>> flow in both directions.
>>>>>>>
>>>>>>> Examination of the traffic coming into and out of this machine 
>>>>>>> seems to
>>>>>>> indicate that the IP addresses aren't being mangled correctly.
>>>>>>> Specifically,
>>>>>>> it appears the internal IP address isn't being changed to 
>>>>>>> reflect the IP
>>>>>>> address of the machine on which RTP Proxy is running, so that 
>>>>>>> when the
>>>>>>> caller tries to send audio back, the IP it's given to reply to is
>>>>>>> 10.10.x.x,
>>>>>>> which obviously won't work.
>>>>>>>
>>>>>>> I have tried experimenting with specifically setting IP 
>>>>>>> addresses in the
>>>>>>> rtpproxy_offer() and _answer() methods to no avail, as well as 
>>>>>>> setting
>>>>>>> various flags in those methods.  However, I must admit that I'm not
>>>>>>> entirely
>>>>>>> sure what's happening under the hood with these methods, or what
>>>>>>> rtpproxy is
>>>>>>> doing with that information when it gets it.  Rather than 
>>>>>>> continue to
>>>>>>> hack
>>>>>>> at this by trial and error, I'm hoping someone here can point me 
>>>>>>> in the
>>>>>>> right direction.
>>>>>>>
>>>>>>> Any advice, example code or pep talks would be greatly appreciated.
>>>>>>>
>>>>>>> Thanks in advance,
>>>>>>>
>>>>>>>           
>>>>>> _______________________________________________
>>>>>> Kamailio (OpenSER) - Users mailing list
>>>>>> Users at lists.kamailio.org
>>>>>> http://lists.kamailio.org/cgi-bin/mailman/listinfo/users
>>>>>> http://lists.openser-project.org/cgi-bin/mailman/listinfo/users
>>>>>>
>>>>>>         
>>>
>>> _______________________________________________
>>> Kamailio (OpenSER) - Users mailing list
>>> Users at lists.kamailio.org
>>> http://lists.kamailio.org/cgi-bin/mailman/listinfo/users
>>> http://lists.openser-project.org/cgi-bin/mailman/listinfo/users
>>
>
>

-- 
Daniel-Constantin Mierla
* Kamailio SIP Masterclass, Nov 9-13, 2009, Berlin
* http://www.asipto.com/index.php/sip-router-masterclass/





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