Hello, There seems to be a lot of forum talk about AudioCodes / Configuration of device. However, what has worked in the past and what works now seems to have changed. Yesterday we had a power outage. For some reason our AudioCodes MP112 gateway decided to restart itself to default. On a positive note the MP114 stayed up and running the whole time perfectly (and yes they are on APC's). I then went to reconfigure the MP112 FXS - which I hadn't done in a while. I got the device registered on 3CX with its two endpoints and calls started to flow back through the unit instantly. However, 1/2 later I got a compliant that outbound calling was no longer working. I made a few changes to the software and configuration and it still did not work. Now that I have played with it for many hours - I have decided I need to reach out to everyone else for some support on this issue. The problem that I am having has seems to be with the invite header (or so the 3CX Server Log is indicating)...please see below: AudioCodes FXS #1: Extension 102 - Internal Address - 192.168.76.10 Public Address of AudioCodes Location: 126.96.36.199 - Site A - Behind router this site, however, STUN is on the AudioCodes Device Public Address of PBX Location: 188.8.131.52 - Site PBX (internal address of PBX is 192.168.0.125) Extension Trying to Call: 951 at Site PBX 11:52:39.561 [CM502001]: Source info: From: <sip:email@example.com>;tag=1c149023079<sip:firstname.lastname@example.org;user=phone> 11:52:39.561 [CM503013]: Call(152): Incoming call rejected, caller is unknown; msg=SipReq: INVITE email@example.com tid=ac149403280 cseq=INVITE firstname.lastname@example.org / 2 from(wire) 11:52:39.408 [CM500002]: Unidentified incoming call. Review INVITE and adjust source identification: INVITE sip:email@example.com;user=phone SIP/2.0 Via: SIP/2.0/UDP 184.108.40.206;branch=z9hG4bKac149026332 Max-Forwards: 70 Contact: <sip:firstname.lastname@example.org> To: <sip:email@example.com;user=phone> From: <sip:firstname.lastname@example.org>;tag=1c149023079 Call-ID: email@example.com CSeq: 1 INVITE Allow: REGISTER, OPTIONS, INVITE, ACK, CANCEL, BYE, NOTIFY, PRACK, REFER, INFO, SUBSCRIBE, UPDATE Supported: em, 100rel, timer, replaces, path, resource-priority User-Agent: Audiocodes-Sip-Gateway-MP-112 FXS/v.5.20A.026.007 Privacy: none P-Asserted-Identity: <tel:102> Content-Length: 0 If anyone has had outgoing call problems on the AudioCodes MP-11x (2/4/8) - and can share how they go around it, that would be deeply appreciated. If you have any questions about the scenario above please feel free to share any input and once again this is the FXS model not FXO. Thanks.