VB.NET MultiThreaded Server Socket Programming

The MultiThreaded Server Socket Program showcased here is a VB.NET Console-based application designed to handle concurrent connections from multiple clients simultaneously. This advanced server program utilizes multithreading capabilities to efficiently manage and respond to incoming client requests in parallel, ensuring optimal performance and scalability.

To fully comprehend and appreciate the intricacies of this MultiThreaded Server Socket Program, it is advisable to review the fundamentals of Socket Programming outlined in the previous section. Familiarizing oneself with the core concepts, principles, and techniques discussed in the Socket Programming section will provide a solid foundation for understanding the complexities and benefits of the MultiThreaded Server Socket Program.

By studying the Socket Programming section beforehand, developers can gain valuable insights into the underlying mechanisms and best practices of socket communication. This knowledge serves as a stepping stone to comprehending the intricacies involved in developing a robust and efficient multi-threaded server application.

The MultiThreaded Server Socket Program enables concurrent handling of multiple clients, offering a highly efficient and responsive communication channel. Leveraging multithreading techniques, the server program can effectively manage client connections, process their requests in parallel, and provide timely and accurate responses.

The Multithreaded Socket Programming has two sections.

1. Multithreaded Server Socket Program

2. Multithreaded Client Socket Program

Multithreaded Server Socket Program

In this implementation, we create a Server Socket using the TcpListener class and configure it to listen on PORT 8888. When the server receives a request from a client, it passes the client request instance to a separate class called handleClient.

Within the handleClient class, a dedicated thread is created to handle the communication between the server-side client instance and the external client. This thread ensures independent and concurrent communication between the server and the connected clients.

By utilizing a separate thread for each client request, the server can establish connections with multiple clients simultaneously. This multi-threaded approach enables independent and concurrent communication between the server and each connected client. Consequently, the server can handle multiple client requests concurrently, facilitating efficient and responsive communication.

The use of threads in the handleClient class ensures that each client connection operates independently, preventing any interference or delays caused by other client interactions. This threading mechanism provides a robust and scalable solution, allowing the server to handle numerous client connections simultaneously while maintaining efficient communication.

Create a new VB.NET Console Application project and put the following source code in the project.

Full Source VB.NET
Imports System.Net.Sockets Imports System.Text Module Module1 Sub Main() Dim serverSocket As New TcpListener(8888) Dim clientSocket As TcpClient Dim counter As Integer serverSocket.Start() msg("Server Started") counter = 0 While (True) counter += 1 clientSocket = serverSocket.AcceptTcpClient() msg("Client No:" + Convert.ToString(counter) + " started!") Dim client As New handleClinet client.startClient(clientSocket, Convert.ToString(counter)) End While clientSocket.Close() serverSocket.Stop() msg("exit") Console.ReadLine() End Sub Sub msg(ByVal mesg As String) mesg.Trim() Console.WriteLine(" >> " + mesg) End Sub Public Class handleClinet Dim clientSocket As TcpClient Dim clNo As String Public Sub startClient(ByVal inClientSocket As TcpClient, _ ByVal clineNo As String) Me.clientSocket = inClientSocket Me.clNo = clineNo Dim ctThread As Threading.Thread = New Threading.Thread(AddressOf doChat) ctThread.Start() End Sub Private Sub doChat() Dim requestCount As Integer Dim bytesFrom(10024) As Byte Dim dataFromClient As String Dim sendBytes As [Byte]() Dim serverResponse As String Dim rCount As String requestCount = 0 While (True) Try requestCount = requestCount + 1 Dim networkStream As NetworkStream = _ clientSocket.GetStream() networkStream.Read(bytesFrom, 0, CInt(clientSocket.ReceiveBufferSize)) dataFromClient = System.Text.Encoding.ASCII.GetString(bytesFrom) dataFromClient = _ dataFromClient.Substring(0, dataFromClient.IndexOf("$")) msg("From client-" + clNo + dataFromClient) rCount = Convert.ToString(requestCount) serverResponse = "Server to clinet(" + clNo + ") " + rCount sendBytes = Encoding.ASCII.GetBytes(serverResponse) networkStream.Write(sendBytes, 0, sendBytes.Length) networkStream.Flush() msg(serverResponse) Catch ex As Exception MsgBox(ex.ToString) End Try End While End Sub End Class End Module

The Multithreaded Socket Programming has two sections.

1. Multithreaded Server Socket Program

2. Multithreaded Client Socket Program

To establish successful communication between the server and client, it is imperative to execute the server program before launching the client program. This sequential order ensures the proper functioning and coordination of the client-server interaction.

Running the server program first allows it to initialize and start listening for incoming client connections. The server program prepares the necessary resources and sets up the communication infrastructure, making it ready to accept and handle client requests.

Once the server program is up and running, the client program can be executed. The client program establishes a connection with the server, enabling communication between the client and the server. By following this sequence, the client program can successfully connect to the server and initiate data exchange.

This order of execution, where the server program is started first and then followed by the client program, establishes a synchronized and coordinated communication flow between the two entities. It ensures that the client can effectively connect to the server and initiate communication without encountering any connection or compatibility issues.


Implementing separate threads for each client communication, the server can accommodate multiple client connections concurrently, fostering independent and efficient communication. This approach enables the server to handle numerous client requests simultaneously, providing a scalable solution for multi-client communication scenarios.