I tried tis with just 7 for a prefix, and when I try to dial an FWD number, it seems to drop the leading digit of the FWD number. So I was expecting to dial 7123456 and get to FWD number 123456, but insted looking at the log it dialled 23456.
Also, I don't seem to be able to make inbound calls from FWD to my loocal Asterisk machine. If I do a grep register on the conf file I notice there is no register form my FWD account. When I set this up manually I used a register command ???