Hi All, here is our test case <mobile phone> -- 4G -- <INTERNET> -- <FreeSWITCH> FreeSWITCH version: 1.6.20 We found that shared address 100.64.0.0/10 will be selected in FreeSWITCH rtp candidate if 4G provider use this kind of ip address. Is it possible to tell FreeSWITCH choose correct public ip address instead of shared address? here is some part of fs_cli output for reference *remode sdp* a=candidate:3652076590 1 udp 2122260223 100.101.139.101 34013 typ host generation 0 network-id 1 network-cost 900 a=candidate:2959346671 1 udp 1686052607 101.10.88.182 24563 typ srflx raddr 100.101.139.101 rport 34013 generation 0 network-id 1 network-cost 900 a=candidate:2536356062 1 tcp 1518280447 100.101.139.101 9 typ host tcptype active generation 0 network-id 1 network-cost 900 *audio candidate* 018-07-26 16:51:26.460474 [DEBUG] switch_core_media.c:3481 Save audio Candidate cid: 1 proto: udp type: host addr: 100.101.139.101:34013 2018-07-26 16:51:26.460474 [DEBUG] switch_core_media.c:3481 Save audio Candidate cid: 1 proto: udp type: srflx addr: 101.10.88.182:24563 2018-07-26 16:51:26.460474 [DEBUG] switch_core_media.c:3523 Searching for rtp candidate. 2018-07-26 16:51:26.460474 [DEBUG] switch_core_media.c:3528 Choose rtp candidate, index 0, 100.101.139.101:34013 *video candidate* 2018-07-26 16:51:26.460474 [DEBUG] switch_core_media.c:3481 Save video Candidate cid: 1 proto: udp type: host addr: 100.101.139.101:52174 2018-07-26 16:51:26.460474 [DEBUG] switch_core_media.c:3481 Save video Candidate cid: 1 proto: udp type: srflx addr: 101.10.88.182:24214 2018-07-26 16:51:26.460474 [DEBUG] switch_core_media.c:3523 Searching for rtp candidate. 2018-07-26 16:51:26.460474 [DEBUG] switch_core_media.c:3528 Choose rtp candidate, index 0, 100.101.139.101:52174 Thanks in advance. Sincerely Albert