I have a setup in place that consists of a Spa9000 device running a ITSP supplied via engin australia. This is currently set to ring inbound to a hunt group. This functions intially without issue, the problem only occurs when a call is missed on this hunt group and it is sent to voicemail. When there is a voicemail attached to one of the line in the hunt group any call to that group recieves a busy signal and cannot connect. Any information on how to correct this issue will be greatly appreciated.
Thank you for sending the full config. Please check out this link for a great examples: https://www.myciscocommunity.com/docs/DOC-6445
Comparing your setup; you may want to add to the AA Dial plan... From: (10x|xxx.) to (10x|xxxx<:127.0.0.1:5083>|xxx.)
This document was specifically addressing the setup of AA to be included if you're interested in adding the voice prompts.
Or, you may just want to change your Contact list to read cfwd=aa rather than cfwd=vmm which is the management side of voicemail and may not be able to route correctly without the full path, i.e. 2102:cfwd=2102