Help me please Asterisk 1.4

Hi
I have no outlets in my asteriks sends me a error:

WARNING12349 app_dial.c1202 dial_exec_full: unable to create channel of type SIP cause 3 no route to destination

Please help me!!!

Configure your OS’ TCP setting, in particular route command or DHCP setting, so that there is a route to the IP address of the called party.