Hi Community, Currently we are testing the following topology that works fine, ONLY IF the option *Record all calls* remain unchecked on Call Queue Agents. -- Softwares used Firefox v55.0.3 (32 bits) SIPjs v0.78 3CX Phone System Professional Edition v15.0.0 3CXPhone for Windows v15.5.3849.1 -- Call Topology (DirectSIP) Caller (from SIPjs running Firefox) address : email@example.com proxy : @domain.onsip.com Callee address : firstname.lastname@example.org proxy : @subdomain.3cx.fr --- Call Queue Extension : 80000 polling strategy : Prioritized Hunt Agents : 00004 and 00003 -- Agents Status 00001 is unregistered, and all forwarding rules set to: forward to Extension 80000 Call Queues 00004 Current Status : Avalaible, Queues Status : LoggedIn 00003 Current Status : Avalaible, Queues Status : LoggedIn -- Test 1 : *Record all calls* is unchecked for ext. 00004 >>> Call is successfully forwarded to 00004 >>> When 00004 pick up ringing phone as audio (and enable video during session), Re-INVITE is succesfully received by SIPjs >>> No problem, all is ok (audio, video) -- Test 2 : *Record all calls* is checked for ext. 00004 >>> Call is successfully forwarded to 00004 >>> When 00004 pick up ringing phone as audio, call is dropped after 1 second >>> Web Page return errors: >>> DOMException [InvalidSessionDescriptionError: "New remote description has fewer m-sections than the previous remote description." code: 0 nsresult: 0x0 By comparing remote SDP (on Firefox debug about:webrtc) on both test1 and test 2, we noticed that remote SDP has changed on test 2 when *Record all calls* is checked so it creates the bug. If you need more details on remote SDP, please check attached 3cx PS activity log file (please read file content from bottom to up). -- QUESTION We want *Record all calls* enabled on all our Call Queues Agents, so what would be the workaround to make both Call Forwarding and Record All Calls working together on audio and video call ? Thanks for helping answers.