Is this an update unmanaged gateway or sip trunk?
On Dec 11, 2012 3:08 PM, "Josh Patten" <jpat...@ezuce.com> wrote:

> Holy incoherent sentences Batman!
>
> "The culprit, I believe, is sipX inserting conflicting connection
> information into the SDP
> In the INVITE, and is unnecessarily inserting the WAN address into the SDP
> even though the , causing the media relay to attempt to send the RTP out of
> the WAN interface to the gateway."
>
> Should read:
>
> The culprit, I believe, is sipX inserting conflicting connection
> information into the SDP in the INVITE and is unnecessarily inserting the
> public IP address of sipX into the SDP even though the gateway is in the
> same subnet as the sipX server, causing the media relay to attempt to send
> the RTP through the media relay and out over the internet to the gateway.
>
>
> On Tue, Dec 11, 2012 at 1:56 PM, Josh Patten <jpat...@ezuce.com> wrote:
>
>> Chris Rawlings of Blue Cloud Consulting and myself were on the phone with
>> Sangoma attempting to determine why hairpinned calls were resulting in no
>> Audio, and believe we may have found an issue in the way sipX modifies the
>> SDP (Sangoma uses FreeSWITCH).
>>
>> So here is the calling scenario:
>>
>>    1. Call comes in from +16107413324 (PSTN CALLER) to 7175463006 (Auto
>>    Attendant)
>>    2. call is transferred to extension 212, which is set to perform call
>>    forwarding (at the same time) to 7174680293 (Cell Phone)
>>    3. If the call is answered on 212, no audio
>>    4. If the call is answered on cell phone, there is audio
>>
>>
>> The culprit, I believe, is sipX inserting conflicting connection
>> information into the SDP
>> In the INVITE, and is unnecessarily inserting the WAN address into the
>> SDP even though the , causing the media relay to attempt to send the RTP
>> out of the WAN interface to the gateway.
>>
>> Here is the SDP for step 1 (generated by the gateway):
>>
>> v=0
>> o=nsc 1355222135 1355222136 IN IP4 192.168.10.19
>> s=nsc
>> c=IN IP4 192.168.10.19
>> t=0 0
>> m=audio 27938 RTP/AVP 0 8 101 13
>> a=rtpmap:101 telephone-event/8000
>> a=fmtp:101 0-16
>> a=ptime:20
>>
>> Here is the SDP that is generated internally by FreeSWITCH IVR and sent
>> to the Proxy:
>> v=0
>> o=FreeSWITCH 1355235729 1355235730 IN IP4 192.168.10.9
>> s=FreeSWITCH
>> c=IN IP4 192.168.10.9
>> t=0 0
>> m=audio 12894 RTP/AVP 9 101 13
>> a=rtpmap:9 G722/8000
>> a=rtpmap:101 telephone-event/8000
>> a=fmtp:101 0-16
>> a=rtpmap:13 CN/8000
>> a=ptime:20
>>
>> And here is what we send back in our 200 OK to the gateway after
>> traversing the Proxy:
>> v=0
>> o=FreeSWITCH 1355235655 1355235656 IN IP4 192.168.10.9
>> s=FreeSWITCH
>> *c=IN IP4 192.168.10.9*
>> t=0 0
>> m=audio 30496 RTP/AVP 0 101 13
>> *c=IN IP4 24.229.51.65 <---- THIS IS THE PUBLIC IP OF SIPX*
>> a=rtpmap:0 PCMU/8000
>> a=rtpmap:101 telephone-event/8000
>> a=fmtp:101 0-16
>> a=rtpmap:13 CN/8000
>> a=ptime:20
>> a=x-sipx-ntap:X192.168.10.9-24.229.51.65;14
>>
>> Why is the proxy messing with the SDP like this when there is clearly no
>> need to rewrite it for a call that the RTP is terminating on devices on the
>> same subnet?
>>
>> I've attached a trace of the SDP example.
>>
>> --
>> Josh Patten
>> eZuce
>> Solutions Architect
>> O.978-296-1005 X2050
>> M.979-574-5699
>> http://www.ezuce.com
>>
>>
>
>
> --
> Josh Patten
> eZuce
> Solutions Architect
> O.978-296-1005 X2050
> M.979-574-5699
> http://www.ezuce.com
>
>
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> sipx-dev mailing list
> sipx-dev@list.sipfoundry.org
> List Archive: http://list.sipfoundry.org/archive/sipx-dev/
>

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