User Datagram Protocol

1 min read

Pronunciation

[yoo-zer dat-uh-gram proh-tuh-kawl]

Analogy

is like sending postcards through the mail—you write the message and and send it off without acknowledgment; some may arrive out of order or not at all.

Definition

A core Internet transport layer that provides minimal‑overhead, connectionless delivery of datagrams without guaranteed delivery or ordering.

Key Points Intro

is characterized by:

Key Points

Connectionless: No handshake before data transmission.

Unreliable: No built‑in retransmission or ordering guarantees.

Low latency: Minimal protocol overhead.

Application‑managed reliability: Apps handle loss, ordering, and congestion control.

Example

light clients use -based discovery (discv4) to rapidly find peers without the overhead of handshakes.

Technical Deep Dive

uses a simple header with source/destination ports, length, and checksum. The does not maintain connection . Applications must handle fragmentation, loss detection, and reassembly if needed. Commonly used for DNS, VoIP, and real‑time services.

Security Warning

flood attacks (e.g., amplification) can overwhelm hosts; network filters and are essential.

Caveat

Lack of reliability requires additional logic at the for error handling.

Related Terms

TCP

IP

Blockchain & Cryptocurrency Glossary

User Datagram Protocol - Related Articles