simplification: You have phone number 123 (intead of 13435465654654654)
using phone with number 123 You want to dial number 123 and ring phone number 123. for me it’s a loop.
If your telephone doesn’t have 2 lines (like x-lite or SPA-941) Asterisk will count it “busy”.
what do You see in CLI> (no debug for now please) when You make a call ?