7.1 Transport Layer Protocols (TCP and UDP) - CCNA1: Chapter 7 - Transport Layer HD

In this leson we examine the role of the transport layer in encapsulating application data for use by the network layer. We also examine the two Transport layer protocols, Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). We identify that the role of the Transport layer is to provide three main functions - multiplexing, segmentation and reassembly and error checking The chapter explains how TCP and UDP operate and which popular applications use each protocol. The chapter explains how UDP datagrams and TCP segments have headers added in front of the data that include a source port number and destination port number. These port numbers enable data to be directed to the correct application running on the destination computer. The application developer decides the transport layer protocol that best meets the requirements for the application.