[Freeswitch-users] NAT: SDP with local IP in o-line unicast_address

[Peter Steinbach]

Hell,

we have the following problem:

Our Freswitch is behind NAT. We are sending faxes to a SIP provider.
Dependend on the destination number, the faxes are received or not.
Faxes are always sent via the same SIP provider and the same dialplan,
but I expect, they may be routed differently via other, subsequent SIP
providers.

Regarding the SDP I can see, that the c-line does contain the our
external IP, but the o-Line does contain the local IP in the
unicast_address field.
We are routing the call via a defined gateway in the external profile,
which has external_sip_ip set and external_rtp_ip set.
Dialplan is:
<action application="export" data="t38_passthru=true"/>
<action application="set" data="proxy_media=true"/>
<action application="bridge"
data="sofia/gateway/QSC/06912345678 at sip.qsc.de"/>

Here is the SDP
====================================
v=0.
o=FreeSWITCH 1037989557 1037989558 IN IP4 192.168.206.241.
s=FreeSWITCH.
c=IN IP4 212.xxx.xxx.106.
t=0 0.
m=audio 12056 RTP/AVP 0 8.
a=rtpmap:0 PCMU/8000/1.
a=rtpmap:8 PCMA/8000/1.
a=maxptime:240.
====================================

I suspect, that the following SIP providers may have a problem with the
o-line with the local IP.
So - Is there any way to control this? E.g. via Dialplan variable?

ACL also seems to be fine
2014-11-07 12:31:10.599563 [NOTICE] switch_utils.c:324 Adding
192.168.0.0/16 (allow) [] to list rfc1918.auto
2014-11-07 12:31:10.599563 [NOTICE] switch_utils.c:324 Adding
192.168.0.0/16 (allow) [] to list nat.auto

I see the same behaviour also in
https://freeswitch.org/jira/browse/FS-5909 "ext-xxx-ip ignored with
proxy_media turned on"
There is a link for a patch, which is no longer available. Did this go
into the main release? Does anybody have this patch?


-- 
With kind regards
Peter