Packetization Layer Path MTU Discovery (PLMTUD) For UDP Transports Using Session Traversal Utilities for NAT (STUN)

Document Type Expired Internet-Draft (tram WG)
Authors Marc Petit-Huguenin  , Gonzalo Salgueiro  , Felipe Garrido 
Last updated 2021-02-20 (latest revision 2020-08-19)
Replaces draft-petithuguenin-tram-stun-pmtud
Stream IETF
Intended RFC status Proposed Standard
Expired & archived
pdf htmlized (tools) htmlized bibtex
Stream WG state Submitted to IESG for Publication
Document shepherd Tolga Asveren
Shepherd write-up Show (last changed 2018-04-20)
IESG IESG state Expired (IESG: Dead)
Action Holders
Consensus Boilerplate Yes
Telechat date
Responsible AD Magnus Westerlund
Send notices to Gonzalo Camarillo <>, Tolga Asveren <>
IANA IANA review state Version Changed - Review Needed

This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


The datagram exchanged between two Internet endpoints have to go through a series of physical and virtual links that may have different limits on the upper size of the datagram they can transmit without fragmentation. Because fragmentation is considered harmful, most transports and protocols are designed with a mechanism that permits dynamic measurement of the maximum size of a datagram. This mechanism is called Packetization Layer Path MTU Discovery (PLPMTUD). But the UDP transport and some of the protocols that use UDP were designed without that feature. The Session Traversal Utilities for NAT (STUN) Usage described in this document permits retrofitting an existing UDP-based protocol with such a feature. Similarly, a new UDP-based protocol could simply reuse the mechanism described in this document.


Marc Petit-Huguenin (
Gonzalo Salgueiro (
Felipe Garrido (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)