Networking Bible

Chapter 17. Internet Transport Protocol

IN THIS CHAPTER

• How data is transported on the Internet

• Factors that influence IP network performance

• What is contained in an IP packet

• How data flow is managed

• Connections and ports

Transmission Control Protocol (TCP) and Internet Protocol (IP) are the two protocols that give rise to the acronym TCP/IP. TCP/IP is a set of protocols or agreed standards that are used to send and manage communications on a packet switched network. TCP is the technology that establishes a virtual connection between systems, manages data transmission, and ensures that the data has been reliably transferred. The data that is contained in a packet is TCP data. The mechanism used to get packets to their destination is IP. The way TCP does what it does impacts the majority of Internet communications, as well as how applications are built; it also affects network performance. IP, which is discussed in Chapter 18, is the method used to package data sent across a packet switched network and includes the methods for not only packaging data but for addressing as well.

TCP solves the problem of how to ensure reliable communications when the medium you transmit over is inherently unreliable. Packets may take different routes to get to their destination, arrive out of sequence, or be dropped entirely. TCP assembles the data by sequencing the packets, ensuring that all packets are valid, and requesting retransmission of any packet that is missing or damaged.

Devices connected over ...