Packetization Layer Path MTU Discovery (PLMTUD) For UDP Transports Using Session Traversal Utilities for NAT (STUN)
draft-ietf-tram-stun-pmtud-16

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 00
• 01
• 02
• 03
• 04
• 05
• 06
• 07
• 08
• 09
• 10
• 11
• 12
• 13
• 14
• 15
• 16

TRAM                                                   M. Petit-Huguenin
Internet-Draft                                        Impedance Mismatch
Intended status: Standards Track                            G. Salgueiro
Expires: September 3, 2020                                    F. Garrido
                                                                   Cisco
                                                           March 2, 2020

Packetization Layer Path MTU Discovery (PLMTUD) For UDP Transports Using
               Session Traversal Utilities for NAT (STUN)
                     draft-ietf-tram-stun-pmtud-16

Abstract

   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.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on September 3, 2020.

Petit-Huguenin, et al.  Expires September 3, 2020               [Page 1]
Internet-Draft                 STUN PMTUD                     March 2020

Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Overview of Operations  . . . . . . . . . . . . . . . . . . .   4
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   6
   4.  Probing Mechanisms  . . . . . . . . . . . . . . . . . . . . .   6
     4.1.  Simple Probing Mechanism  . . . . . . . . . . . . . . . .   7
       4.1.1.  Sending a Probe Request . . . . . . . . . . . . . . .   7
       4.1.2.  Receiving a Probe Request . . . . . . . . . . . . . .   8
       4.1.3.  Receiving a Probe Response  . . . . . . . . . . . . .   8
     4.2.  Complete Probing Mechanism  . . . . . . . . . . . . . . .   8
       4.2.1.  Sending a Probe Indications and Report Request  . . .   9
       4.2.2.  Receiving an ICMP Packet  . . . . . . . . . . . . . .   9
       4.2.3.  Receiving a Probe Indication and Report Request . . .   9
       4.2.4.  Receiving a Report Response . . . . . . . . . . . . .  10
       4.2.5.  Using Checksums as Packet Identifiers . . . . . . . .  10
       4.2.6.  Using Sequence Numbers as Packet Identifiers  . . . .  11
   5.  Probe Support Signaling Mechanisms  . . . . . . . . . . . . .  12
     5.1.  Explicit Probe Support Signaling Mechanism  . . . . . . .  12
     5.2.  Implicit Probe Support Signaling Mechanism  . . . . . . .  13
   6.  STUN Attributes . . . . . . . . . . . . . . . . . . . . . . .  13
     6.1.  IDENTIFIERS . . . . . . . . . . . . . . . . . . . . . . .  13
     6.2.  PMTUD-SUPPORTED . . . . . . . . . . . . . . . . . . . . .  13
     6.3.  PADDING . . . . . . . . . . . . . . . . . . . . . . . . .  13
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  14
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
     8.1.  New STUN Methods  . . . . . . . . . . . . . . . . . . . .  14
     8.2.  New STUN Attributes . . . . . . . . . . . . . . . . . . .  14
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  15