RFC 5405 · BEST CURRENT PRACTICE · 2008

Unicast UDP Usage Guidelines for Application Designers

Overview

RFC 5405, “Unicast UDP Usage Guidelines for Application Designers”, is a Best Current Practice document published in November 2008 by L. Eggert, G. Fairhurst. It has been obsoleted by RFC 8085 — refer to the newer document for the authoritative version. The canonical text is published by the RFC Editor.

Abstract

The User Datagram Protocol (UDP) provides a minimal message-passing transport that has no inherent congestion control mechanisms. Because congestion control is critical to the stable operation of the Internet, applications and upper-layer protocols that choose to use UDP as an Internet transport must employ mechanisms to prevent congestion collapse and to establish some degree of fairness with concurrent traffic. This document provides guidelines on the use of UDP for the designers of unicast applications and upper-layer protocols. Congestion control guidelines are a primary focus, but the document also provides guidance on other topics, including message sizes, reliability, checksums, and middlebox traversal. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.

Abstract as published in the RFC, via rfc-editor.org.

What “Best Current Practice” means

Documents the IETF community's recommended operational or procedural practice rather than a protocol specification.

Read this RFC

The canonical text of RFC 5405 is hosted at rfc-editor.org. Available in TXT,HTML.

Relationships to other RFCs
Obsoleted by
RFC 8085
Other RFCs from 2008

Who Is Online

In total there are 78 users online: 0 registered, 71 guests and 7 bots.

Most users ever online was 5,555 on 17 Jul 2026, 3:23 am.

Bots: AhrefsBot Applebot Baiduspider Bingbot Other Bot PetalBot SemrushBot

Users active in the past 15 minutes. Total registered members: 372