Sip trunk isolation

HELLO Dears

how i can isolate sip trunk channels?
i am using of 4fxo gateway(external device) and i maked sip trunk for dialin and dialout.
in example i have 2 extensions (301,302),i want for dialout; extension 301 used of port 1 of gateway and 302 used of port 2 of gateway for dial out.

please help me how i can isolate and analyze sip trunk channels for dial out.

thanks

if you found a solution please contact to me and me too

Dear tadpole

thank you for reply,ok if i get a good response i send you too.

thanks