c# send TCP packet without TCP handshake

Question

I am attempting to interop with a custom hardware device.

It requires the first TCP packet to contain a data payload

I tried to achieve this using TcpClient in System.Net.Sockets

   TcpClient tcpclnt = new TcpClient();
   tcpclnt.Connect("192.168.1.11", 1500);
   Stream stm = tcpclnt.GetStream();
   byte[] ba = messagestr.StringToByteArray();                   
   stm.Write(ba, 0, ba.Length);

However wireshark shows that this code sends a number of TCP/IP packets to establish a connection and the data packet (containing messagestr) is the 4-5th packet.

How can I make C# send the data in the FIRST TCP packet?

Answer 1

Use UDP to send only one packed without establishing a session. You are literally asking TCP not to be TCP.