Heres what I did with a similar situation:
In Call Handling, the first entry is the warehouse IP phone, and I have it set for 20 seconds.
The second entry is the front desks DID number NPA-NXX-XXXX and I have it set to 50 seconds.
Then at the bottom of this tab, under Phones will ring: I set as Sequentially.
Is this what you were looking for?
I don't want to use DID numbers. I would rather say in an advanced rule: "If ring for xx seconds and no answer, ring ext ###." -- This would eliminate the need for voicemail on the actual extension. The other option I guess would be to not give out the extension to anyone and always tell them to call ext 108 if they need to reach the warehouse...
Jordan, Here's another idea that might work for you. There's a way to forward to a "ring group", sometimes called a "hunt group". Here's a help topic that explains how.
Forwarding to other user's phones, adding phone, and Ring Groups
We also need call queue to be able to forward to another 'backup' call queue extension after a set amount of time.
