The two primary protocols used at the transport layer of the network model are TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).
Understanding TCP and UDP
-
TCP: TCP is a connection-oriented protocol, meaning it establishes a dedicated connection between the sender and receiver before transmitting data. This connection ensures reliable data delivery through error checking and retransmission of lost packets. TCP is ideal for applications requiring reliable data transfer, such as web browsing (HTTP), email (SMTP), and file transfer (FTP). Think of it like a registered letter – you're guaranteed delivery.
-
UDP: UDP is a connectionless protocol. It doesn't establish a dedicated connection; instead, it sends data packets individually without guaranteed delivery or order. This makes it faster but less reliable. UDP is suitable for applications where speed is prioritized over reliability, such as online gaming, video streaming, and DNS lookups. Think of it as sending a postcard – it's faster, but there's no guarantee of arrival.
Multiple sources confirm this: GeeksforGeeks (https://www.geeksforgeeks.org/transport-layer-protocols/), Wikipedia (https://en.wikipedia.org/wiki/Transport_layer), and numerous other articles and books mention TCP and UDP as the two most widely used transport layer protocols. For instance, an O'Reilly book on Windows NT TCP/IP Network Administration explicitly states that TCP and UDP are the two most important protocols at this layer. (https://www.oreilly.com/library/view/windows-nt-tcpip/1565923774/ch01s06.html)
