VB.NET Socket Programming

A Socket represents a crucial endpoint within a bidirectional communication link between two programs, specifically the Server Program and Client Program, operating across a network. The establishment of a socket program necessitates the utilization of two distinct programs, namely the Server Socket Program (Server) and the Client Socket Program (Client).

VB.Net socket example

1. Server Program: A Server Socket Program, operating on a computer, possesses a socket that is bound to a specific Port Number on that machine. This server socket actively listens for incoming requests from clients.
2. Client Program: On the other hand, a Client Socket Program needs to be aware of the IP Address (Hostname) associated with the computer where the Server Socket Program resides. Additionally, it also requires knowledge of the designated Port Number that the server has assigned for listening to client requests.

Once the communication is established , the Server and Client can read or write their own sockets.

Communication Protocols

Socket Programming employs two distinct communication protocols: TCP/IP (Transmission Control Protocol/Internet Protocol) Communication and UDP/IP (User Datagram Protocol/Internet Protocol) Communication.

1. TCP/IP Communication: TCP/IP is a reliable and connection-oriented protocol widely used for Socket Programming. It ensures the ordered and error-free delivery of data packets between the communicating parties. TCP/IP establishes a virtual circuit between the sender and receiver, guaranteeing the reliable and accurate transmission of data. This protocol is commonly used in applications where data integrity and reliability are crucial, such as file transfers, email communication, and web browsing.
2. UDP/IP Communication: UDP/IP, on the other hand, is a connectionless and unreliable communication protocol used in Socket Programming. It provides a lightweight and low-overhead approach for transmitting data packets without establishing a dedicated connection between the sender and receiver. Unlike TCP/IP, UDP/IP does not guarantee the ordered delivery or error correction of data packets. It is commonly used in applications where real-time data streaming, video conferencing, or online gaming necessitate fast transmission with less concern for data integrity.

In the following section we are going to communicate a Server Socket Program and Client Socket Program through VB.NET using TCP/IP Communication.

In the above picture shows the communication interfaces .

Server Socket Program:

Here Server Socket Program is done through a Console based VB.NET application . Here the Server listening for the client's request , and when the server get a request from the Client , Server sends the response to Client . Click the following link to see in detail of a Server Socket Program .

Client Socket Program:

The Client Socket Program is a windows based application . When the client start its get connect the server and send requests , and also receive the response from Server . Click the following link to see in detail of Client Socket Program.

How to run this program ?

The Socket Programming has two sections.

1. Server Socket Program

2. Client Socket Program

Once you have completed coding the program, the initial step is to launch the Server Socket Program. Upon doing so, a DOS screen will appear, displaying a confirmation message indicating that the server has started successfully.

Following that, you proceed to start the Client Socket Program. Upon launching the client program, a message will be displayed on the client screen, indicating that the client has started. Simultaneously, you can verify on the server screen that a message appears, confirming the acceptance of the connection from the client.

At this point, both the Server Socket Program and the Client Socket Program are successfully connected. To test the communication between the two, you can click on the designated button (typically labeled as "Click here to send data to Server") within the client window. As a result, you will observe changes in the messages displayed on both the server and client screens, indicating the successful transmission of data between the two programs.