Класс Socket

                clientSocket = new TcpClient();
                clientSocket.Connect(ip, port);
                NetworkStream stream = clientSocket.GetStream();
                StreamWriter sw = new StreamWriter(stream);
                sw.WriteLine(UserName);
                sw.WriteLine(StateID);

struct Packet
{
    public int Size;
    public byte[] data;
}

string cstr = "string" + '\0';

// writer
public static void WriteCString(this BinaryWriter Writer, string text)
{
    Writer.Write(Encoding.UTF8.GetBytes(text));
    Writer.Write((byte)0);
}
// reader
public static string ReadCString(this BinaryReader reader, Encoding encoding)
{
    var bytes = new List<byte>();
    byte b;
    while ((b = reader.ReadByte()) != 0)
    {
        bytes.Add(b);
    }
    return encoding.GetString(bytes.ToArray());
}