Using socket to cmmunicate node app to c# service - sockets

Question

[Sorry for my bad English]
Hi!
I have to communicate between a node.js application [client side] and c# application [server side].
Each side sends pings to the other, on TCP protocol.
I Successed to create both client and server side, but I have to problems:
after the first ping from the client to the server, the client throws an error:
This socket has been ended by the other party
What i'm doing wrong?
The server reads the incomeing pings into a large buffer.
When I decode it to string, I get string with length of 4096.
How I read the excact message length?
This is the server side code: [c#, .NET 6]
using System.Net;
using System.Net.Sockets;
using System.Text;
Console.WriteLine("Start...");
CancellationTokenSource cts = new();
TcpListener listener = new(IPAddress.Any, 11111);
try
{
listener.Start();
Console.WriteLine("Listining...");
var clientCounter = 0;
var ct = cts.Token;
while (!ct.IsCancellationRequested)
{
using TcpClient client = await listener.AcceptTcpClientAsync(ct)
.ConfigureAwait(false);
using NetworkStream stream = client.GetStream();
_ = PrintUploadedData(stream, ct);
_ = PushData(stream, ct);
clientCounter++;
Console.WriteLine("New client ({0}) connected", clientCounter);
}
}
finally
{
cts.Cancel();
listener.Stop();
}
async Task PrintUploadedData(NetworkStream stream, CancellationToken ct)
{
var buf = new byte[4096];
while (!ct.IsCancellationRequested)
{
var timeout = CancellationTokenSource.CreateLinkedTokenSource(
ct,
new CancellationTokenSource(TimeSpan.FromMinutes(3)).Token);
try
{
var amountRead = await stream.ReadAsync(buf, timeout.Token);
if (timeout.IsCancellationRequested)
{
Console.Error.WriteLine("No Message.");
break;
}
if (amountRead == 0) break; //end of stream.
var message = Encoding.UTF8.GetString(buf);
Console.WriteLine(message);
}
catch (OperationCanceledException)
{
Console.Error.WriteLine("Time out");
break;
}
}
}
async Task PushData(NetworkStream stream, CancellationToken ct)
{
while (!ct.IsCancellationRequested)
{
var messageToSend = DateTime.Now.TimeOfDay.ToString();
var messageBytes = Encoding.UTF8.GetBytes(messageToSend);
await stream.WriteAsync(messageBytes, ct).ConfigureAwait(false);
await Task.Delay(TimeSpan.FromSeconds(15), ct);
}
}
And the client side code [node.js]:
import { Socket } from 'net';
var client = new Socket();
client.on('connect', () => console.log("CONNECTED"));
client.on('data', data => console.log("data", data.toString()));
client.on('error', err => console.error(err));
client.connect(11111, "127.0.0.1");
printMessages();
async function printMessages() {
for (let i = 0; i < 10; i++) {
client.write('Ping ' + i);
await sleep(4000);
}
}
function sleep(ms) {
return new Promise(resolve => setTimeout(resolve, ms));
}