How many dahdi channels do you have? Inbound call is using 1 channel, and the outbound leg of the call appears to be failing due to no free dahdi channels.
Asterisk is a back to back user agent (B2BUA) meaning that it always stays in the call path. When you forward a call to an external DID, a second channel is set up and then bridged to the first, meaning you need at least 2 trunk channels. The channels don’t have to be the same technology tho, so you can add a SIP trunk and set up your outbound routes to use both SIP and DAHDI.
there is one trunk now Dahdi01 and is attached to an outbound route, you are saying i can create another trunk, lets say sip and attach to the same outbound trunk like in sequence 2? is that correct?