Hi. I try to make working kamailio on TCP infront of asterisk

Before to send to asteisk any packet i added 
$fs=ip.add.re.ss:port

Also discribed 
listen=tcp:ip.add.re.ss:port

But kamailio send outgoing packets from random prot throug TCP
Presume i configured 5060 port but it send from 35410 port.

googling on a core functions didn gives me any answer.

May be i forget something to set at the config?