Hi Folks!

I’m trying to make a client/server program using VB.NET. I’ve got an example from MSDN website. After some changes, I got a working version. Everything is working fine, however there is a weird delay when client sends a package to server. I’m running it in my LAN and it shouldn’t take 20 seconds to send an 18-character-long string. Code below:

Thanks for your help!

**SERVER side**

Try

Dim server As System.Net.Sockets.TcpListener

server = Nothing

Dim localAddr As System.Net.IPAddress = System.Net.IPAddress.Parse("192.168.1.2")

Dim port As Int32 = 13000

server = New System.Net.Sockets.TcpListener(localAddr, port)

' Start listening for client requests.

server.Start()

' Buffer for reading data

Dim bytes(256) As Byte

Dim data As String = Nothing

' Enter the listening loop.

While True

lblMessage.Text = "Waiting for connection..."

' Perform a blocking call to accept requests.

Dim client As System.Net.Sockets.TcpClient = server.AcceptTcpClient()

lblMessage.Text = "Connected"

data = Nothing

' Get a stream object for reading and writing

Dim stream As System.Net.Sockets.NetworkStream = client.GetStream()

Dim i As Int32

i = stream.Read(bytes, 0, bytes.Length)

' Translate data bytes to a ASCII string.

data = System.Text.Encoding.ASCII.GetString(bytes, 0, i)

' analyse data sent...

lblMensagem.Text = "Data OK. Doing the job..."

' Send back a response.

Dim msg As Byte() = System.Text.Encoding.ASCII.GetBytes("OK")

stream.Write(msg, 0, msg.Length)

' Shutdown and end connection

client.Close()

End While

Catch ex As System.Net.Sockets.SocketException

MessageBox.Show(ex.ToString())

End Try

**CLIENT side**

Try

Dim client As New System.Net.sockets.TcpClient("192.168.1.2", 13000)

' Translate the passed message into ASCII and store it as a Byte array.

Dim data As [Byte]() = System.Text.Encoding.ASCII.GetBytes("8888;888.88;888.88")

' Get a client stream for reading and writing.

' Stream stream = client.GetStream();

Dim stream As System.Net.sockets.NetworkStream = client.GetStream()

' Send the message to the connected TcpServer.

stream.Write(data, 0, data.Length)

' Receive the TcpServer.response.

' Buffer to store the response bytes.

data = New [Byte](256) {}

' String to store the response ASCII representation.

Dim responseData As [String] = [String].Empty

' Read the first batch of the TcpServer response bytes.

Dim bytes As Int32 = stream.Read(data, 0, data.Length)

responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes)

' Close everything.

stream.Close()

client.Close()

Catch ex As System.Net.Sockets.SocketException

MessageBox.Show(ex.ToString())

End Try