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

[Örn Arnarson]

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,
>>>>
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