I have used 3cx for about 2 months with not many problems, but today I started to get this error, see below: ------- 31-Oct-2014 16:33:08.654 [CM500002]: Unidentified incoming call. Review INVITE and adjust source identification: Invite-UNK Recv Req INVITE from 192.168.2.1:5060 tid=-7fbcdc239c39e370a61a52ee44867c14 Call-ID=7fbcdc239c39e370a61a52ee44867c14: INVITE sip:email@example.com:5060 SIP/2.0 Via: SIP/2.0/UDP 192.168.2.1:5060;branch=z9hG4bK-7fbcdc239c39e370a61a52ee44867c14;rport=5060 Max-Forwards: 70 Record-Route: <sip:firstname.lastname@example.org;lr> Contact: <sip:email@example.com:5060> To: "9011441382000269"<sip:firstname.lastname@example.org:5060> From: "7001"<sip:email@example.com:5060>;tag=0217ce5c Call-ID: 7fbcdc239c39e370a61a52ee44867c14 CSeq: 1 INVITE Allow: INVITE, ACK, CANCEL, BYE Content-Type: application/sdp User-Agent: sipcli/v1.8 Content-Length: 278 v=0 o=sipcli-Session 764863912 221672684 IN IP4 192.168.2.1 s=sipcli c=IN IP4 192.168.2.1 t=0 0 m=audio 16488 RTP/AVP 18 0 8 101 a=fmtp:101 0-15 a=rtpmap:18 G729/8000 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=ptime:20 a=sendrecv ------- I would not even have seen the above error if it had not repeated itself 25 times and blacklisted my providers trunk. the ip address "192.168.2.1" listed is my voip providers ip address all calls come from this ip. the "INVITE sip:9011441382000269" looks like some kind of international number. I dont have an extension 7001 listed "From: "7001"<sip:firstname.lastname@example.org:5060>;tag=0217ce5c" I find this in the server event log: event id 12290 The IP 192.168.2.1 has been blacklisted for 86400 sec. Reason: Too many failed authentications! event id 4100 Trunk L:10001(megapath) has changed status to unregistered. This means that no more calls will pass via this trunk. Please check your network connection and the voip provider or event id 12293 Registration at megapath has failed. Destination (sip:*email@example.com:5060) is not reachable, DNS error resolving FQDN, or service is not available. I remove the ip "192.168.2.1" from the ip blacklist and reregister my provider and everything is working fine. I would appreciate any help, my first thought was someone is trying to access 3cx from the outside to make calls, so I checked my firewall and I do not have any open ports accessible from the public ip address. Thanks! 3cxnub.