To cut the long story short, I've setup a Wamp server with local virtual host for domain like sample.dev, now I've bind my static IP and port 80 to my Apache and asked the client to make some changes in his hosts file and add x.x.x.x sample.dev , I've also configured my httpd virtual host like this :

<VirtualHost *:80>
    ServerAlias sample.dev
    DocumentRoot 'webroot_directory'
</VirtualHost>

Client can reach to my web server using the direct access by ip address, but when he tries using the sample domain looks like he gets in to some infinite loop. The firewall is off too. What would be the problem?!

Thanks.