EventBasedNetListener listener = new EventBasedNetListener();
NetServer server = new NetServer(listener, 2 /* maximum clients */, "SomeConnectionKey");
server.Start(9050 /* port */);

listener.PeerConnectedEvent += peer =>
{
    Console.WriteLine("We got connection: {0}", peer.EndPoint); // Show peer ip
    NetDataWriter writer = new NetDataWriter();                 // Create writer class
    writer.Put("Hello client!");                                // Put some string
    peer.Send(writer, SendOptions.ReliableOrdered);             // Send with reliability
};

while (!Console.KeyAvailable)
{
    server.PollEvents();
    Thread.Sleep(15);
}

server.Stop();

EventBasedNetListener listener = new EventBasedNetListener();
NetClient client = new NetClient(listener, "SomeConnectionKey");
client.Start();
client.Connect("localhost" /* host ip or name */, 9050 /* port */);
listener.NetworkReceiveEvent += (fromPeer, dataReader) =>
{
    Console.WriteLine("We got: {0}", dataReader.GetString(100 /* max length of string */);
};

while (!Console.KeyAvailable)
{
    client.PollEvents();
    Thread.Sleep(15);
}

client.Stop();