No matching peer found

I get all the time this message, can somebody help me?

[May 25 20:33:30] NOTICE[27411] chan_sip.c: Registration from “111” sip:[email protected]’ failed for ‘’ - No matching peer found

I think you have a phone on your system that is not properly configured (either the phone end or the server end). The phone is trying to register but there is no entry for it on the server. As I said, it could be a config error at either end.