Networking Core Protocols

Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are the two main transport layer protocols, and understanding their differences is fundamental to networking and security analysis. TCP is connection-oriented, meaning it establishes a formal connection before transmitting data through a three-way handshake (SYN, SYN-ACK, ACK). This connection-oriented nature ensures reliability through acknowledgments, sequencing, and retransmission of lost packets. UDP, in contrast, is connectionless and operates on a "fire and forget" principle. It sends data without establishing a connection or waiting for acknowledgments. This makes UDP much faster and more efficient for time-sensitive applications where occasional packet loss is acceptable. Common UDP applications include video streaming, online gaming, DNS queries, and VoIP calls. The choice between TCP and UDP depends on the application's requirements. Web browsing uses TCP because every byte of the HTML, CSS, and JavaScript must arrive correctly and in order. However, a video streaming service might use UDP because if a few frames are lost, it's better to continue with the stream than to pause and wait for retransmission. From a security perspective, both protocols have their considerations. TCP's handshake process can be exploited in SYN flood attacks, while UDP's connectionless nature makes it easier to spoof source addresses. Understanding these protocols helps in analyzing network traffic and identifying potential security issues.