Hello. I need to make application which could connect with itself:

(on my pc) (other pc)
[myapp] <-- --> [myapp]

I've never wrote anything using qtnetwork so I need something really simple, first network app, just creating empty server, because I feel quite lost in tons of lines from advanced network applications. Does someone know good page/tutorial where I could find something like this? Because now I even can't listen from new tcpserver and I even don't know if it's natural.