C# - an established connection was aborted by the software in your host machine Error

Question

I am building a Mock Server using TCPListener.

When I tried to debug my code by running the client, I was able to read the request on the server. But on the client side, an exception is being thrown. Here is the exception I got from the trace:

System.ServiceModel.CommunicationException: The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '00:05:00'. ---> System.IO.IOException: Unable to read data from the transport connection: An established connection was aborted by the software in your host machine. ---> System.Net.Sockets.SocketException: An established connection was aborted by the software in your host machine

Here is the code of I implemented on the server:

TcpClient client = listener.AcceptTcpClient();
NetworkStream nwStream = client.GetStream();
byte[] buffer = new byte[client.ReceiveBufferSize];
int bytesRead = nwStream.Read(buffer, 0, client.ReceiveBufferSize);
var dataReceived = Encoding.ASCII.GetString(buffer, 0, bytesRead);

byte[] sendBytes = null;
try
{
    var output = "POST HTTP/1.1 200 OK\r\n";
    output += "Server: Apache-Coyote/1.1\r\n";
    output += "Content-Type: application/soap+xml\r\n";
    output += "Content-Length: 632\r\n";
    output += "Date: Thu, 06 Aug 2015 02:06:39 GMT\r\n\r\n";
    output +=
        "<S:Envelope xmlns:S=\"http://www.w3.org/2003/05/soap-envelope\"><S:Header></S:Header><S:Body></S:Body></S:Envelope>";
    sendBytes = Encoding.ASCII.GetBytes(output);
    nwStream.Write(sendBytes, 0, sendBytes.Length);
    nwStream.Flush();
}
catch (SocketException se)
{
    throw;
}

client.Close();

Edit

I also tried to disable my firewall but the exception still occurs.

Solution

Setting the correct Content-Length fixed it.

If Content-Length is greater than the actual length, the client-side will continue to wait for the remaining parts of the response. But since the server is already done with sending the response, it will end the process.