This is my implementation of a TCP server with heavy inspiration from this article and this talk by one of the creators of NodeJS, Ryan Dahl.
This implementation mimics a live chat server using a live TCP server. Code illustrates how to handle new and closing sockets, logging data, and adding features on the client side.
Run the server by entering the following command in your computer's terminal:
node server.js
This will launch the TCP server. If your computer has telnet installed, you can establish a generic connection, which will send the data stream to the server as well as any other connected client.
In the project directory is also a client.js, which connects to the TCP server. This client has a continual prompt that is more user friendly, and mimics a live chat service. To use this client, run:
node client.js
I have the nodemon package registered in my package.json file just in case you'd like to work on the server while it is up and running. Just run npm install at the project root directory.
TCP stands for Transmission Control Protocol. It is a protocol that describes how to establish a reliable connection (meaning, that both messengers will be reasonably certain that the communication is reliable, and if there any issues arises, this protocol has a way of letting one or both messengers know). The protocol is defined by the following features :
- A two way connection stream between two machines
- a "handshake" that includes the initial request, a response confirming the request, and transmission of the data itself
- streaming data in packets, which itself contains metadata (headers) that describe how the packets should be assembled and in what order
TCP is a network level protocol that describes how machines should communicate data. Other protocols, such as HTTP (Hypertext Transfer Protocol) rely on TCP to know that more sophisticated, application-level data is being properly communicated.