486 Busy Here/INVITE from one specific extension to another specific ext. on an internal call

[UsamaKhan]

No setting has been changed in 3CX server and all of a sudden extension 230 is unable to call 200 (goes to 200's voicemail). Other than that all the extensions are able to call each other.
200 is at location A and 230 is at location B, both of them provisioned through SBCs.
230 is a Fanvil X4U handset but the issue is the same even when calling using iPhone app.
200 responds as busy to 230 even though it's idle.

 

[Alejandro_3CX]

Hi @UsamaKhan do you have the same issue calling from another extension to the 200?

Please check the following on ext 200:

• Status Profile set to Available (dial *30)
• From ext 200 dial *60
• Also check on the phone that you don't have any DND enabled.
• Check on ext 200 that you don't have any exception rule to avoid calls from the ext 230

Have a great weekend!

 

[JohnS_3CX]

In addition to what my colleague said above, if 200 has an IP phone, make sure the phone has not added 230 in their Blocked list. Otherwise everytime they call, the other side will send a busy and the call will go to voicemail..

You can also unplug their phone and log them into a 3CX client. With the phone now unplugged, the extension should be reachable from 230 if this was indeed the case.