3456 [Sep 6 07:45:52] NOTICE[20066] chan_sip.c: Registration from '"590940371"<sip:590940371@58.61.13.212>' failed for '221.236.12.33' - No matching peer found
24300 [Sep 6 08:00:33] NOTICE[20066] chan_sip.c: Registration from '"3002" <sip:3002@58.61.13.212>' failed for '221.236.12.33' - Wrong password
Even though hackers use robot (machine) to generate a password patterns, the frequently of password hacking will not be very high. As a result, for a 10-16 digit long password should be good enough to reduce the chances of being hacked.
[Sep 9 08:28:36] NOTICE[3157] chan_sip.c: Registration from '"1475489026"<sip:1475489026@183.38.120.228>' failed for '115.238.28.151' - No matching peer found
[Sep 9 08:29:24] NOTICE[3157] chan_sip.c: Registration from '"3712696007"<sip:3712696007@183.38.120.228>' failed for '115.238.28.151' - No matching peer found
[Sep 8 21:08:20] NOTICE[7344] chan_sip.c: Registration from '"465708066"<sip:465708066@116.25.174.173>' failed for '89.115.178.75' - No matching peer found