How can I set one device is server and remaining all devices are clients in ios

How can I set one device is server and remaining all devices are clients
in ios

I'm new to iOS Socket Programming. I want to set one device is server and
remaining all devices are clients. I googled and found the sample project
from below link.
http://developer.apple.com/library/ios/samplecode/WiTap/Introduction/Intro.html
But I find difficulty to understand the code in that sample project.
please guide me and post any sample code.