Asterisk + Panasonic transfer

I have Asterisk 1.8 server connected to Panasonic TDE-200 via E1 card.
Recently I faced a problem.
For example I bave two extensions at Astersik side : 3005 and 3006
And two extnsions at Panasonic side : 1570 and 1571
All calls are successfull.
But here is the problem: when I set fwd at Panasonic side from 1570 to 3006 and dial 1570 from 3005, I get hangup:

-- Called OOH323/1570@city == Everyone is busy/congested at this time (1:1/0/0)
When I call 1570 from 3005, from 1570 a user can transfer call to 3006 or any other destination.
Any ideas?
Thanks in advance.

Solved : I should have disabled CF fucntion on Panasonic side.