The Great Protocol Debate: TCP vs. UDP

The Great Protocol Debate: TCP vs. UDP

IT professionals or enthusiasts may already be familiar with the Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). Among the most commonly used protocols in networking are TCP and UDP, a discovery beginners to the field will quickly make. This article helps readers understand the differences between TCP and UDP by comparing and contrasting their ports, protocols, and purposes.

What are TCP and UDP?

Users employ TCP and UDP as protocols for communication over a network. Reliable and efficient data transfers between devices are ensured by TCP and UDP. A connection-oriented protocol, TCP establishes a connection between two devices before transmitting data. TCP guarantees that data is delivered in the correct order and received by the receiving device. UDP is a connectionless protocol that transmits data without establishing a connection beforehand. UDP sends data as quickly as possible without guaranteeing delivery or order of the data.

Ports and Protocols

Default ports for port numbers vary for each protocol. Both TCP and UDP have port numbers ranging from 0 to 65535, but they use different sets of port numbers. Reserved for specific purposes, some port numbers exist. HTTP uses port 80, HTTPS uses port 443, SMTP uses port 25, and Remote Desktop Protocol (RDP) uses port 3389 as common default ports for TCP protocols. Typically, web browsing, secure web browsing, email communication, and remote desktop access use these ports, respectively. DNS queries use port 53, Network Time Protocol (NTP) uses port 123, and Simple Network Management Protocol (SNMP) uses port 161, as common default ports for UDP protocols. Typically, Domain Name System (DNS) queries, time synchronization, and network device management use these ports, respectively.


TCP is perfect for applications that demand reliable and ordered data delivery, as previously mentioned. An example of where TCP is commonly used is in web browsing, email communication, file transfers, and remote desktop access. UDP is employed in applications that necessitate fast transmission speeds yet can tolerate some loss of data packets. Streaming video and audio, online gaming, and VoIP (Voice over Internet Protocol) are applications that remain fully functional while using UDP.

The Great Debate: TCP vs. UDP

The superiority of either protocol has been the subject of extensive debates. Neither protocol is superior since each has its unique strengths and weaknesses. The selection of a protocol depends heavily on the specific requirements of the application being used. Interestingly, the IT community has a running joke that goes something like this: "TCP is like a loving relationship, slow and steady wins the race. UDP is like a one night stand, quick and dirty." While it may be a bit crass, this joke illustrates the basic difference between the two protocols quite well. While UDP is sometimes unreliable but fast, TCP is slow, steady, and reliable.


TCP and UDP are among the most commonly used protocols in networking, to conclude. Selecting the appropriate protocol ultimately depends on the specific requirements and needs of the application being used. Making informed decisions when selecting the appropriate protocol for one's requirements can be assisted by understanding the differences between TCP and UDP. When deciding between TCP and UDP, ask yourself this question: "Do I want a loving relationship or a one-night stand?" The choice is ultimately yours!