Guidelines for Defining Packet Timestamps
draft-ietf-ntp-packet-timestamps-01

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Last updated 2018-03-05
Replaces draft-mizrahi-intarea-packet-timestamps
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Network Working Group                                         T. Mizrahi
Internet-Draft                                                   Marvell
Intended status: Informational                                 J. Fabini
Expires: September 6, 2018               Vienna University of Technology
                                                               A. Morton
                                                               AT&T Labs
                                                           March 5, 2018

               Guidelines for Defining Packet Timestamps
                  draft-ietf-ntp-packet-timestamps-01

Abstract

   This document specifies guidelines for defining binary packet
   timestamp formats in networking protocols at various layers.  It also
   presents three recommended timestamp formats.  The target audience of
   this memo includes network protocol designers.  It is expected that a
   new network protocol that requires a packet timestamp will, in most
   cases, use one of the recommended timestamp formats.  If none of the
   recommended formats fits the protocol requirements, the new protocol
   specification should specify the format of the packet timestamp
   according to the guidelines 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
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   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
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   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 6, 2018.

Copyright Notice

   Copyright (c) 2018 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

Mizrahi, et al.         Expires September 6, 2018               [Page 1]
Internet-Draft              Packet Timestamps                 March 2018

   (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  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
     2.2.  Abbreviations . . . . . . . . . . . . . . . . . . . . . .   3
     2.3.  Terms used in this Document . . . . . . . . . . . . . . .   4
   3.  Packet Timestamp Specification Template . . . . . . . . . . .   4
   4.  Recommended Timestamp Formats . . . . . . . . . . . . . . . .   5
     4.1.  Using a Recommended Timestamp Format  . . . . . . . . . .   6
     4.2.  NTP Timestamp Formats . . . . . . . . . . . . . . . . . .   6
       4.2.1.  NTP 64-bit Timestamp Format . . . . . . . . . . . . .   6
       4.2.2.  NTP 32-bit Timestamp Format . . . . . . . . . . . . .   8
     4.3.  The PTP Truncated Timestamp Format  . . . . . . . . . . .   9
   5.  Synchronization Aspects . . . . . . . . . . . . . . . . . . .  10
   6.  Timestamp Use Cases . . . . . . . . . . . . . . . . . . . . .  11
     6.1.  Example 1 . . . . . . . . . . . . . . . . . . . . . . . .  12
     6.2.  Example 2 . . . . . . . . . . . . . . . . . . . . . . . .  12
   7.  Packet Timestamp Control Field  . . . . . . . . . . . . . . .  12
     7.1.  High-level Control Field Requirements . . . . . . . . . .  13
     7.2.  Control Field Categories  . . . . . . . . . . . . . . . .  14
     7.3.  Control Field Features and Elements . . . . . . . . . . .  15
       7.3.1.  Timestamp Format  . . . . . . . . . . . . . . . . . .  16
       7.3.2.  Timestamp Format Specification  . . . . . . . . . . .  16
       7.3.3.  Timestamp Precision . . . . . . . . . . . . . . . . .  17
       7.3.4.  Timestamp Timescale . . . . . . . . . . . . . . . . .  17
       7.3.5.  Timestamp Leap Second . . . . . . . . . . . . . . . .  17
       7.3.6.  Reference Clock . . . . . . . . . . . . . . . . . . .  18
       7.3.7.  Provable Signature  . . . . . . . . . . . . . . . . .  18
       7.3.8.  Custom Extension  . . . . . . . . . . . . . . . . . .  18
     7.4.  Control Field Payload Definition  . . . . . . . . . . . .  19
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