[asterisk-users] Setting up ring group

[Tom Moore]

Hi guys,
What's the best way to setup a ring group that contains 6 extensions so that
when a call comes in there starts a 30 second timer and the first available
device is rang instead of ringing all extensions at the same time?
What I want it to do is cycle through the extensions and have the system
ignore the ones that are busy and if there are not any free extensions in
the ring group to have the system drop the caller to voicemail.
If none of the extensions are present in the group I'd like to also drop to
voicemail.
Basically what I'm looking for is a multiple extensions version of the
standard extension macro with multiple devices and the exten busy state
ignored.

Tom