TBB provides a Call Hunt like feature where you can have unanswered TBB calls automatically ring through to one or more telephone numbers that you specify.

This is done using the FMFM feature. Below is a description of such FMFM usage that minimizes the ring time for a caller:

1. Set the ring time to 15 or 20 secs in Call Answer Ring Time to produce 3-4 rings.
   
   
2. Setup an FMFM list with 1-2 phones (your cell phone, office phone) and Ring Option Simultaneous (ring all) and associate it with the Default Treatment.
   
   
3. All incoming calls on the TBB line then ring 3-4 times at most, before being routed to the FMFM list phones.
   
   
4. The caller hears 3-4 rings. He then hears "Please wait while we locate your party; or press 1 to leave a message". At this point the caller can leave a message, OR wait a bit more, if it is really important, for you to pick up one of the other phone(s).

Another option would be to set an Action within the Default Treatment to FORWARD to your cell immediately during the TimeOfDay you are most likely not at home. You might have to edit all your other "Treatments", and you would need to have cell phone voicemail, beccause TBB is literally out of the loop on a Call Forward !