The provider we are using is sending the following:

SDP from first 183 message from peer to freeswitch

v=0
o=Flowroute 3154 3154 IN IP4 66.234.182.42
s=sip call
t=0 0
m=audio 32264 RTP/AVP 0 101 13
c=IN IP4 66.234.182.42
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=ptime:20
a=rtpmap:13 CN/8000

SDP from second 183 message from peer to freeswitch

v=0
o=Flowroute 13797 3057 IN IP4 64.86.96.138
s=SIP Media Capabilities
t=0 0
m=audio 15262 RTP/AVP 0 101
c=IN IP4 64.86.96.138 <----------- different than first 183
a=rtpmap:0 PCMU/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=sendrecv
a=ptime:20

SDP from 200 OK from peer to freeswitch

v=0
o=Flowroute 13797 3057 IN IP4 64.86.96.138
s=SIP Media Capabilities
t=0 0
m=audio 15262 RTP/AVP 0 101
c=IN IP4 64.86.96.138 <----------- different than first SDP, same as second SDP
a=rtpmap:0 PCMU/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=sendrecv
a=ptime:20

And freeswitch is sending the RTP data to IP it received in the first SDP, and ignoring the updated IP in the following SDP's.

The originate string has ignore_early_media=true.

I applied the patch from SFSIP-82 but it did not fix the problem. Have not tried to reproduce with
freeswitch trunk yet. (we are using revision 9072)