Call Forward CFB and CFU Flow Problem


I have just came across a bit of an issue with busy and unavailable call forwarding. Immediate works fine.

When one of our users at extension 3001 sets a busy or no reply forward to 3002 and neither have a voicemail box available then 3001 will ring for 15seconds, 3002 will ring for 15secs then the call drops with ‘Congestion’

If I do the same and 3002 has a mailbox the call will drop after 15sec ringing of 3002

If i then do the same with 3001 and 3002 having a mailbox then the call goes to the 3001 mailbox instead of 3002.

If an Immediate forward it set everything works as it should.

Can anyone explain how to get a call to follow the forward properly end either ring forever on an extension with no VM or to goto the final destination vm rather than the original extension?

I’m running 2.11 Asterisk 11

UPDATE - I’ve got it behaving properly by setting ‘Call Forward Ring Time’ on the first extension to ‘Always’ however this does not make sense as the little help bubble says that it should automatically go to Always if there is no mailbox enabled. This is a nightmare now as I have over 400 extensions that I’m going to have to change and remember to set when I create new ones.