The number you have dialed is no longer in service

I am getting this error every other day. Sip provider is Voip.MS. I have allow guest to on. I am able to make outbound calls but not incoming. logs show:

2016-08-04 08:44:03] VERBOSE[3053][C-00000000] pbx.c: Executing [[email protected]:6] Log(“SIP/”, "WARNING,“Rejecting unknown SIP connection from"”) in new stack
[2016-08-04 08:44:03] WARNING[3053][C-00000000] Ext. s: “Rejecting unknown SIP connection from”

Do not allow “guest” to be enabled. Hackers can make calls through your PBX. That’s bad.

Your incoming connection configuration is not set up correctly. I’m going to guess that you didn’t allow them in through that specific address.