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@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