Transmission Control Protocol (TCP)

TCP (Transmission Control Protocol): A protocol that provides a reliable, ordered delivery of data over an IP network. TCP uses a three-way handshake to establish a connection and uses sequence numbers to ensure that data is delivered in the correct order.

TCP socket stream

A TCP (Transmission Control Protocol) socket is a type of network socket that is used to create a connection between a client and a server. A socket is a software endpoint that establishes bidirectional communication between a server and one or more clients. TCP sockets are a specific type of socket that uses the TCP protocol for transmitting data.

A socket stream is a flow of data that is transmitted between a client and a server using a TCP socket. When a client establishes a connection with a server using a TCP socket, a socket stream is created that allows the two parties to send and receive data over the connection. The socket stream provides a reliable, ordered, and error-checked transmission of data between the client and server.

TCP socket streams are used in many different applications, including web browsing, email, and file transfer. They are an essential part of the underlying infrastructure that makes the internet possible.

A TCP connection will be established after the TLS handshaking

If the browser was written by Google, the browser might negotiate with the server to upgrade from HTTP to SPDY protocol1. The later version of Chrome favors HTTP/2 instead of SPDY protocol. 2

The browser will send a GET request to fetch content, the GET request contains information that can

  • identify the browser
  • State what type of response it will accept
  • the connection header asking whether TCP connection should remain open for further requests
  • send cookies3 the browser has for the domain.

HTTP/1.14 defines the “close” connection option for the sender to signal that the connection will be closed after completion of the response. For example, Connection: close.

  1. SPDY is a protocol designed to reduce web page load latency. SPDY does this by multiplexing multiple HTTP requests into a single connection, compressing request and response headers, and prioritizing resources. ↩︎

  2. HTTP/2 is an application-level protocol for sending and receiving data over the Internet. It is an updated version of HTTP/1.1, and is designed to reduce latency and improve web performance. It supports multiplexing, header compression, and server push technology, among other features. ↩︎

  3. Cookies are key-value pairs that track the state of a website between different page requests. Cookies store the name of the logged-in user, a secret number that was assigned to the user by the server, some user’s setting etc. The cookies will be stored in a text file on the client, and sent to the server with every request. ↩︎

  4. HTTP/1.1 is a version of the Hypertext Transfer Protocol (HTTP) used for communication between web browsers and web servers. It is an application-level protocol for distributed, collaborative, hypermedia information systems. It was first defined in RFC 2068 in 1997, and has since been updated several times. It is the most widely used version of HTTP, and is the basis for other HTTP versions such as HTTP/2. ↩︎

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