Entensions Registrations Issue

Hi,

I am new to Asterisk, I have installed it on a CentOs 5.2 Server, everything seems to look good as far as I know. I well might be wrong. I have installed GUI2.0 and have made a couple of extensions (6000, 6001) which are reflected in extensions.conf. Made them using GUI. Also I have made a Dial Plan using GUI…

The issue is I am trying to connect a soft phone (tried Xlite and idefisk) but the IAX and SIP both wont register I know I am missing something here but have no idea about it that what I am doing which is causing this I have tried the tutorials on asteriskguru but with no success…

My aim is to install an A2Billing on this machine and use it for Wholesale and as a SIP server…

Any help is greatly appreciated…

Bilal

Any one who can help me out here please I am really stuck on this one !

Sincerely,
Bilal