Hello I have tried both of these optoins, wanting to remove the x.x.x.x IP, perhaps wrong context, I did it based on the IP I am sending invite to so not to affect other providers I did also just try "o=" in the remove line option sdp_remove_line_by_prefix("o=FreeSWITCH 1617020253 1617020254 IN IP4 x.x.x.x"); sdp_mangle_ip("x.x.x.x/32","y.y.y.y.y");   ------------------------------------------------------------------------ *From: *"David Villasmil" &lt;david.villasmil.work(a)gmail.com&gt; *To: *"sr-users" &lt;sr-users(a)lists.kamailio.org&gt; *Sent: *Tuesday, March 30, 2021 1:39:01 PM *Subject: *Re: [SR-Users] SDP Change Should work. What have you tried? On Tue, 30 Mar 2021 at 12:27, Nick Meyjes &lt;nick(a)convergedgroup.net <mailto:nick@convergedgroup.net>> wrote: Hi, I am trying to send calls to a provider that is switching to Nokia SBCs. They dont like seeing any IP other than our kamailio SBC in the messaging, I changed the contact but I cant find a way to change the owner line in the SDP I have try mangler and SDPOPS to change but neither seem to work on changing or removing the owner line Any ideas? Nick _______________________________________________ Kamailio (SER) - Users Mailing List sr-users(a)lists.kamailio.org <mailto:sr-users@lists.kamailio.org> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users <https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users> -- Regards, David Villasmil email: david.villasmil.work(a)gmail.com <mailto:david.villasmil.work@gmail.com> phone: +34669448337 _______________________________________________ Kamailio (SER) - Users Mailing List sr-users(a)lists.kamailio.org https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users _______________________________________________ Kamailio (SER) - Users Mailing List sr-users(a)lists.kamailio.org https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users