What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
The User Datagram Protocol (UDP) is a transport protocol that carries application messages as datagrams over IP. It uses port numbers to direct each datagram to an application, but UDP itself does not guarantee delivery, order, or protection against duplicates.
What UDP means
UDP stands for User Datagram Protocol. It provides a minimal transport service between application programs: an application sends a message in a datagram, and UDP adds port addressing so the receiving system can pass it to the intended application. IP addresses identify network endpoints; an endpoint can be described by the combination of an IP address and a port number.
Jon Postel, author of the original specification, described UDP this way: “the protocol is transaction oriented, and delivery and duplicate protection are not guaranteed.” RFC 768, published by the Internet Engineering Task Force in 1980, defines the protocol.
Do these 3 things before closing this tab:
1Fix the driver behind crashes, sound loss and screen glitches2Repair Windows errors before they cause bigger problems3Scan for outdated or missing drivers - takes under a minuteWhat a UDP datagram contains
A UDP datagram consists of a header followed by its data. The header has four fields:
#1 Best Overall
- Funny computer desktop support gift for any information technology special. Great for any computer science major.
- Give it to any data scientist, programmer or programmer. Perfect for any computer gamer geek who loves their keyboard, mouse and monitor.
- Lightweight, Classic fit, Double-needle sleeve and bottom hem
- Source port: Identifies the sending application’s port. It can be set to zero when the sender does not provide a source port.
- Destination port: Helps identify the receiving application on the destination system.
- Length: Gives the length of the UDP header and data together.
- Checksum: Covers information from IP, the UDP header, and the data to help detect errors.
The four fields take up eight octets, so the minimum UDP datagram length is eight octets, even when it carries no data. A checksum is for error detection; it does not confirm that a datagram reached its destination.
What UDP does—and does not—guarantee
UDP does not perform a transport-layer handshake before sending datagrams, and it does not establish a transport connection like a connection-oriented protocol. It also does not guarantee that a datagram will arrive, arrive only once, or arrive in the order it was sent.
Rank #2
If an application needs delivery confirmation, retransmission, duplicate handling, or ordering, it must add those mechanisms itself or use a protocol that supplies the needed behavior. For applications that need ordered, reliable streams, RFC 768 points to TCP. UDP’s lack of built-in guarantees is not the same as an application being unable to build reliability on top of it.
Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →UDP and TCP: the practical distinction
| Aspect | UDP | TCP |
|---|---|---|
| Transport setup | No transport-layer handshake before datagrams are sent. | Connection-oriented; RFC 768 identifies TCP for applications needing reliable, ordered streams. |
| Data model | Messages are sent as datagrams. | Provides a stream rather than UDP’s message-oriented datagrams. |
| Delivery and order | UDP provides no delivery, ordering, or duplicate-protection guarantees. | RFC 768 recommends TCP when an application requires ordered, reliable stream delivery. |
| Application responsibility | The application must supply any additional guarantees it requires. | Uses transport mechanisms for reliable, ordered stream delivery. |
This is a difference in built-in behavior, not a universal speed ranking. Whether UDP or TCP suits a particular application depends on what the application needs and on network conditions.
Rank #3
What applications using UDP over the Internet must consider
UDP leaves many delivery properties to the application, but that does not remove the need to behave responsibly toward other network traffic. The Internet Engineering Task Force’s RFC 8085, UDP Usage Guidelines says applications and protocols using UDP as an Internet transport must use mechanisms that prevent congestion collapse and establish some fairness with concurrent traffic.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
