Asterisk using SIP account dialing out issue

Hi guys, 1st fo all thanks in advanced

I’m very new in this world of VOIP and asterisk config.

This is my scenario.

I have this asterisk box running in my dmz no firewall blocking any ports, I can dial from outside using softphone (zoiper( to my other extentions and it works fine,
When i try to dial my cell phone using a sip account (inphonet) it shows that it has been registered meaning user name, and password are setup correctly in my asterisk box, it never dials out. it shows no route to host.
MENU FOR VOIP TRUNKS I SETUP MY ACCOUNT SETTINGS WITH INPHONET .

Note: When I point my softphone directly to my VOIP provider it work just fine.

thanks a lot .