Legitimate IP blacklisted

[cerien]

My instance is a Version 20.0 Update 4 (Build 487 Release) self hosted.
It is connected by a trunk to an VOIP operator, using registration mechanism.
Though I see no errors in the logs, occasionally, the voip operator IP gets blacklisted. Of course, I can whitelist it, but I would really want to understand why it is being blacklisted. The operator is legitimate, and I doubt anyone reports him for any wrong doing

E.

 

[Alejandro_3CX]

Hi, what is the event about this in the event log? is this a supported voip provider?

 

[tronic]

My instance is a Version 20.0 Update 4 (Build 487 Release) self hosted.
It is connected by a trunk to an VOIP operator, using registration mechanism.
Though I see no errors in the logs, occasionally, the voip operator IP gets blacklisted. Of course, I can whitelist it, but I would really want to understand why it is being blacklisted. The operator is legitimate, and I doubt anyone reports him for any wrong doing

E.

Our best practise is to add the SIP provider IP in the allow list so they don't get blocked. But I can't say I've ever had the provider blocked unless I've entered in the wrong username or password. As Alejandro said above, when you get blacklisted, there should be an entry in the event viewer. Can you post this with IP removed?

 

[cerien]

Hello
I see a legitimate incoming call on the trunk (from the voip provider to 3CX) that triggers:
Unidentified Incoming Call. Review INVITE and adjust source identification:
The sip exchange shows the INVITE, answered by 3cx with 407, another INVITE with credentials, and 403 invalid credentials from 3CX. Obviously, these credentials are correct as the traffic is correctly processed most of the time.
Only weird thing, the DID called on the 3CX used to be a fax, but I see no T38 negotiation, and that should trgger a 486, not 403