read/write through udp socket

I found this free source for sockets
http://www.koders.com/cpp/fidA3ACF7B...8F07FEAD4.aspx
It seems great except for a little problem

Code:

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Socket sc;
sc.UdpSender();//setup socket for sending udp packets
sc.UdpBind(5000);//setup socket for reading udp packets

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If I do this I get an assertion error from the class itself.
My question, can a UDP socket both read and write stuff? or do I need seperate sockets for each function ?

No you can read and write from the same UDP socket.

I'm developing to apps that comunicate through the udp socket. For now the sockets comunicate only in the localhost.
if I bind a socket to a port X in one app, the other one isn't allowed to bind it's socket to port X.. at least I'm getting error, because I can't bind the second socket to the port...
Is this a expected behaviour? how can surpass this ?

You can't bind() to the same port twice on a host. You can bind() and listen() to port X in one application, and in the other application, send data, but not bind(), to port X. In this scenario, one application is the server, and the other is the client. If you think about it, it doesn't make sense for the client to bind to any port because you don't care what port you send data on, but you do care what port the data arrives at.