FreePBX (PBX in a Flash) + Linksys IP Phones, Call Forwarding

I have set up my PBX system but whenever someone tries to transfer a call to a busy extention they have to wait about 15 rings until it tells them that the extention is busy. How can I set it up so that if the extention is busy it tells them imediately and doesn’t try to get through. (If not busy, just not answered it should still try for a while, maybe 5-10 seconds, but if busy it should not waste time trying to get through)

Is this something I have to set in Asterisk or in the phones? I can find “Cfwd No Ans Delay:” in the phones but that’s probably just for when the extention is not busy and thy just haven’t picked it up yet. I want to find some setting for cfwd busy delay and set it to zero.

you have configured the extensions with Call waiting enabled. Disable it.