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Simple Two-way Active Measurement Protocol Optional Extensions
draft-ietf-ippm-stamp-option-tlv-07

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 8972.
Authors Greg Mirsky , Xiao Min , Henrik Nydell , Richard "Footer" Foote , Adi Masputra , Ernesto Ruffini
Last updated 2020-07-28 (Latest revision 2020-07-08)
Replaces draft-mirsky-ippm-stamp-option-tlv
RFC stream Internet Engineering Task Force (IETF)
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Stream WG state Submitted to IESG for Publication
Document shepherd Yali Wang
Shepherd write-up Show Last changed 2020-06-18
IESG IESG state Became RFC 8972 (Proposed Standard)
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Needs a YES. Needs 6 more YES or NO OBJECTION positions to pass.
Responsible AD Martin Duke
Send notices to Yali Wang <wangyali11@huawei.com>
IANA IANA review state IANA OK - Actions Needed
draft-ietf-ippm-stamp-option-tlv-07
Network Working Group                                          G. Mirsky
Internet-Draft                                                    X. Min
Updates: 8762 (if approved)                                    ZTE Corp.
Intended status: Standards Track                               H. Nydell
Expires: January 9, 2021                               Accedian Networks
                                                                R. Foote
                                                                   Nokia
                                                             A. Masputra
                                                              Apple Inc.
                                                              E. Ruffini
                                                                  OutSys
                                                            July 8, 2020

     Simple Two-way Active Measurement Protocol Optional Extensions
                  draft-ietf-ippm-stamp-option-tlv-07

Abstract

   This document describes optional extensions to Simple Two-way Active
   Measurement Protocol (STAMP) that enable measurement of performance
   metrics, in addition to ones supported by the STAMP base
   specification.  The document also defines a STAMP Test Session
   Identifier and thus updates RFC 8762.

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 January 9, 2021.

Copyright Notice

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

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   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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions Used in This Document . . . . . . . . . . . . . .   3
     2.1.  Acronyms  . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   3.  STAMP Test Session Identifier . . . . . . . . . . . . . . . .   4
   4.  TLV Extensions to STAMP . . . . . . . . . . . . . . . . . . .   8
     4.1.  Extra Padding TLV . . . . . . . . . . . . . . . . . . . .  11
     4.2.  Location TLV  . . . . . . . . . . . . . . . . . . . . . .  11
     4.3.  Timestamp Information TLV . . . . . . . . . . . . . . . .  13
     4.4.  Class of Service TLV  . . . . . . . . . . . . . . . . . .  14
     4.5.  Direct Measurement TLV  . . . . . . . . . . . . . . . . .  15
     4.6.  Access Report TLV . . . . . . . . . . . . . . . . . . . .  17
     4.7.  Follow-up Telemetry TLV . . . . . . . . . . . . . . . . .  18
     4.8.  HMAC TLV  . . . . . . . . . . . . . . . . . . . . . . . .  20
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  21
     5.1.  STAMP TLV Registry  . . . . . . . . . . . . . . . . . . .  21
     5.2.  STAMP TLV Flags Sub-registry  . . . . . . . . . . . . . .  22
     5.3.  Synchronization Source Sub-registry . . . . . . . . . . .  22
     5.4.  Timestamping Method Sub-registry  . . . . . . . . . . . .  23
     5.5.  Return Code Sub-registry  . . . . . . . . . . . . . . . .  24
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  25
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  25
   8.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  25
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  25
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  26
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  26
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  27

1.  Introduction

   Simple Two-way Active Measurement Protocol (STAMP) [RFC8762] supports
   the use of optional extensions that use Type-Length-Value (TLV)
   encoding.  Such extensions enhance the STAMP base functions, such as
   measurement of one-way and round-trip delay, latency, packet loss,
   packet duplication, and out-of-order delivery of test packets.  This
   specification defines optional STAMP extensions, their formats, and

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   the theory of operation.  Also, a STAMP Test Session Identifier is
   defined as an update of the base STAMP specification [RFC8762].

2.  Conventions Used in This Document

2.1.  Acronyms

   BDS BeiDou Navigation Satellite System

   BITS Building Integrated Timing Supply

   CoS Class of Service

   DSCP Differentiated Services Code Point

   ECN Explicit Congestion Notification

   GLONASS Global Orbiting Navigation Satellite System

   GPS Global Positioning System [GPS]

   HMAC Hashed Message Authentication Code

   LORAN-C Long Range Navigation System Version C

   MBZ Must Be Zero

   NTP Network Time Protocol [RFC5905]

   PMF Performance Measurement Function

   PTP Precision Time Protocol [IEEE.1588.2008]

   TLV Type-Length-Value

   SSID STAMP Session Identifier

   SSU Synchronization Supply Unit

   STAMP Simple Two-way Active Measurement Protocol

2.2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

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3.  STAMP Test Session Identifier

   The STAMP Session-Sender transmits test packets to the STAMP Session-
   Reflector.  The STAMP Session-Reflector receives the Session-Sender's
   packet and acts according to the configuration and optional control
   information communicated in the Session-Sender's test packet.  STAMP
   defines two different test packet formats, one for packets
   transmitted by the STAMP Session-Sender and one for packets
   transmitted by the STAMP Session-Reflector.  STAMP supports two
   modes: unauthenticated and authenticated.  Unauthenticated STAMP test
   packets are compatible on the wire with unauthenticated TWAMP-Test
   [RFC5357] packets.

   By default, STAMP uses symmetrical packets, i.e., the size of the
   packet transmitted by the Session-Reflector equals the size of the
   packet received by the Session-Reflector.

   A STAMP Session is identified by the 4-tuple (source and destination
   IP addresses, source and destination UDP port numbers).  A STAMP
   Session-Sender MAY generate a locally unique STAMP Session Identifier
   (SSID).  SSID is a two-octet-long non-zero unsigned integer.  A
   Session-Sender MAY use SSID to identify a STAMP test session.  If
   SSID is used, it MUST be present in each test packet of the given
   test session.  In the unauthenticated mode, SSID is located as
   displayed in Figure 1.

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       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Sequence Number                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Timestamp                            |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         Error Estimate        |             SSID              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      |                                                               |
      |                         MBZ (28 octets)                       |
      |                                                               |
      |                                                               |
      |                                                               |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                            TLVs                               ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Figure 1: An example of an extended STAMP Session-Sender test packet
                      format in unauthenticated mode

   An implementation of the STAMP Session-Reflector that supports this
   specification SHOULD identify a STAMP Session using the SSID in
   combination with elements of the usual 4-tuple for the session.
   Before a test session commences, a Session-Reflector MUST be
   provisioned with all the elements that identify the STAMP Session.  A
   STAMP Session-Reflector MUST discard non-matching STAMP test
   packet(s).  The means of provisioning the STAMP Session
   identification is outside the scope of this specification.  A
   conforming implementation of STAMP Session-Reflector MUST copy the
   SSID value from the received test packet and put it into the
   reflected packet, as displayed in Figure 2.

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     0                   1                   2                   3
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                        Sequence Number                        |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                          Timestamp                            |
    |                                                               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |         Error Estimate        |           SSID                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                          Receive Timestamp                    |
    |                                                               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                 Session-Sender Sequence Number                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                  Session-Sender Timestamp                     |
    |                                                               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    | Session-Sender Error Estimate |           MBZ                 |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |Ses-Sender TTL |                   MBZ                         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    ~                            TLVs                               ~
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     Figure 2: An example of an extended STAMP Session-Reflector test
                   packet format in unauthenticated mode

   A STAMP Session-Reflector that does not support this specification
   will return the zeroed SSID field in the reflected STAMP test packet.
   The Session-Sender MAY stop the session if it receives a zeroed SSID
   field.  An implementation of a Session-Sender MUST support control of
   its behavior in such a scenario.  If the test session is not stopped,
   the Session-Sender, can, for example, send a base STAMP packet
   [RFC8762].

   Location of the SSID field in the authenticated mode is shown in
   Figure 3 and Figure 4.

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     0                   1                   2                   3
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                      Sequence Number                          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                                                               |
    |                      MBZ (12 octets)                          |
    |                                                               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                        Timestamp                              |
    |                                                               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |        Error Estimate         |            SSID               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    ~                                                               ~
    |                         MBZ (68 octets)                       |
    ~                                                               ~
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                                                               |
    |                       HMAC (16 octets)                        |
    |                                                               |
    |                                                               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

         Figure 3: Base STAMP Session-Sender test packet format in
                            authenticated mode

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Sequence Number                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        MBZ (12 octets)                        |
      |                                                               |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Timestamp                            |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         Error Estimate        |            SSID               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        MBZ (4 octets)                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Receive Timestamp                      |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        MBZ (8 octets)                         |
      |                                                               |

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      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 Session-Sender Sequence Number                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        MBZ (12 octets)                        |
      |                                                               |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 Session-Sender Timestamp                      |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Session-Sender Error Estimate |                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +
      |                        MBZ (6 octets)                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |Ses-Sender TTL |                                               |
      +-+-+-+-+-+-+-+-+                                               +
      |                                                               |
      |                        MBZ (15 octets)                        |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        HMAC (16 octets)                       |
      |                                                               |
      |                                                               |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       Figure 4: Base STAMP Session-Reflector test packet format in
                            authenticated mode

4.  TLV Extensions to STAMP

   The Type-Length-Value (TLV) encoding scheme provides a flexible
   extension mechanism for optional informational elements.  TLV is an
   optional field in the STAMP test packet.  Multiple TLVs MAY be placed
   in a STAMP test packet.  A TLV MAY be enclosed in a TLV.  TLVs have a
   one-octet-long STAMP TLV Flags field, one-octet-long Type field, and
   two-octet-long Length field that is equal to the length of the Value
   field in octets.  If a Type value for TLV or sub-TLV is in the range
   for Vendor Private Use, the Length MUST be at least 4, and the first
   four octets MUST be that vendor's the Structure of Management
   Information (SMI) Private Enterprise Code, as recorded in IANA's SMI
   Private Enterprise Codes sub-registry, in network octet order.  The
   rest of the Value field is private to the vendor.  The following
   sections describe the use of TLVs for STAMP that extend STAMP
   capability beyond its base specification.

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       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |STAMP TLV Flags|     Type      |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                            Value                              ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

              Figure 5: TLV Format in a STAMP Extended Packet

   where fields are defined as the following:

   o  STAMP TLV Flags - eight-bit-long field.  Detailed format and
      interpretation of flags defined in this specification is below.

   o  Type - one-octet-long field that characterizes the interpretation
      of the Value field.  It is allocated by IANA, as specified in
      Section 5.1.

   o  Length - two-octet-long field equal to the length of the Value
      field in octets.

   o  Value - a variable-length field.  Its interpretation and encoding
      is determined by the value of the Type field.

   The format of the STAMP TLV Flags displayed in Figure 6 and the
   location of flags is according to Section 5.2.

       0 1 2 3 4 5 6 7
      +-+-+-+-+-+-+-+-+
      |U|L|A|R|R|R|R|R|
      +-+-+-+-+-+-+-+-+

                     Figure 6: STAMP TLV Flags Format

   where fields are defined as the following:

   o  U - a one-bit flag.  A Session-Sender MUST set the U flag to 0
      before transmitting an extended STAMP test packet.  A Session-
      Reflector MUST set the U flag to 1 if the Session-Reflector has
      not understood the TLV.

   o  L - a one-bit flag.  A Session-Sender MUST set the L flag to 0
      before transmitting an extended STAMP test packet.  A Session-
      Reflector MUST set the L flag to 1 if the Session-Reflector
      determined the TLV is malformed, i.e., the Length field value of
      the fixed-size TLV is not equal to the value defined for the

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      particular type, or the remaining length of the extended STAMP
      packet is less than the size of the TLV.

   o  A - a one-bit flag.  A Session-Sender MUST set the A flag to 0
      before transmitting an extended STAMP test packet.  A Session-
      Reflector MUST set the A flag to 1 if the STAMP extensions have
      failed HMAC verification (Section 4.8).

   o  R - reserved flags for future use.  These flags MUST be zeroed on
      transmit and ignored on receipt.

   A STAMP node, whether Session-Sender or Session-Reflector, receiving
   a test packet MUST determine whether the packet is a base STAMP
   packet or includes one or more TLVs.  The node MUST compare the value
   in the Length field of the UDP header and the length of the base
   STAMP test packet in the mode, unauthenticated or authenticated based
   on the configuration of the particular STAMP test session.  If the
   difference between the two values is larger than the length of the
   UDP header, then the test packet includes one or more STAMP TLVs that
   immediately follow the base STAMP test packet.  A Session-Reflector
   that does not support STAMP extensions is not expected to compare the
   value in the Length field of the UDP header and the length of the
   STAMP base packet.  Hence the Session-Reflector will transmit the
   base STAMP packet.  It is the local policy on the Session-Sender
   (similar to the handling of SSID == 0 scenario described in
   Section 3) that will control the sender's behavior.

   A system that has received a STAMP test packet with extension TLVs
   MUST validate each TLV:

      If the U flag is set, the STAMP system MUST skip the processing of
      the TLV.  The implementation MUST try to process the next TLV if
      present in the extended STAMP packet.

      If the L flag is set, the STAMP system MUST stop processing the
      remainder of the extended STAMP packet.

      If the A flag is set, the STAMP system MUST discard all TLVs and
      MUST stop processing the remainder of the extended STAMP packet.

      If an implementation of a Session-Reflector does not recognize the
      Type field value, it MUST include a copy of the TLV into the
      reflected STAMP packet.  The Session-Reflector MUST set the U flag
      to 1.  The Session-Reflector MUST try to process the next TLV in
      the extended STAMP packet.

      If a TLV is malformed, the processing of extension TLVs MUST be
      stopped.  The Session-Reflector MUST copy the remainder of the

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      received extended STAMP packet into the reflected STAMP packet.
      The Session-Reflector MUST set the L flag to 1.

   Detected error events MUST be logged.  Note that rate of logging MUST
   be controlled.

4.1.  Extra Padding TLV

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |STAMP TLV Flags|Extra Pad Type |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      ~                         Extra Padding                         ~
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                        Figure 7: Extra Padding TLV

   where fields are defined as the following:

   o  STAMP TLV Flags - is an eight-bit-long field.  Its format is
      presented in Figure 6.

   o  Extra Padding Type - is a one-octet-long field, value TBA1
      allocated by IANA Section 5.1.

   o  Length - two-octet-long field equal to the length of the Extra
      Padding field in octets.

   o  Extra Padding - a pseudo-random sequence of bits.  The field MAY
      be filled with all zeros.

   The Extra Padding TLV is similar to the Packet Padding field in a
   TWAMP-Test packet [RFC5357].  The use of the Extra Padding TLV is
   RECOMMENDED to perform a STAMP test using test packets of larger size
   than the base STAMP packet [RFC8762].  The length of the base STAMP
   packet is 44 octets in the unauthenticated mode or 112 octets in the
   authenticated mode.  The Extra Padding TLV MAY be present more than
   one time in an extended STAMP test packet.

4.2.  Location TLV

   STAMP Session-Senders MAY include the Location TLV to request
   information from the Session-Reflector.  The Session-Sender SHOULD
   NOT fill any information fields except for STAMP TLV Flags, Type, and
   Length.  The Session-Reflector MUST validate the Length value against

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   the address family of the transport encapsulating the STAMP test
   packet.  If the Length field's value is invalid, the Session-
   Reflector MUST zero all fields and MUST NOT return any information to
   the Session-Sender.  The Session-Reflector MUST ignore all other
   fields of the received Location TLV.

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |STAMP TLV Flags| Location Type |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Source MAC                           |
      +                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                               |           Reserved            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                    Destination IP Address                     ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                       Source IP Address                       ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |        Destination Port       |          Source Port          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                 Figure 8: Session-Reflector Location TLV

   where fields are defined as the following:

   o  STAMP TLV Flags - is an eight-bit-long field.  Its format is
      presented in Figure 6.

   o  Location Type - is a one-octet-long field, value TBA2 allocated by
      IANA Section 5.1.

   o  Length - two-octet-long field equal to the length of the Value
      field in octets.  The Length field value MUST equal 20 octets for
      the IPv4 address family.  For the IPv6 address family, the value
      of the Length field MUST equal 44 octets.  All other values are
      invalid.

   o  Source MAC - 6-octet-long field.  The Session-Reflector MUST copy
      the Source MAC of the received STAMP packet into this field.

   o  Reserved - two-octet-long field.  MUST be zeroed on transmission
      and ignored on reception.

   o  Destination IP Address - IPv4 or IPv6 destination address of the
      packet received by the STAMP Session-Reflector.

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   o  Source IP Address - IPv4 or IPv6 source address of the packet
      received by the STAMP Session-Reflector.

   o  Destination Port - two-octet-long UDP destination port number of
      the received STAMP packet.

   o  Source Port - two-octet-long UDP source port number of the
      received STAMP packet.

   The Location TLV MAY be used to determine the last-hop IP addresses,
   ports, and last-hop MAC address for  STAMP packets.  The MAC address
   can indicate a path switch on the last hop.  The IP addresses and UDP
   ports will indicate if there is a NAT router on the path.  It allows
   the Session-Sender to identify the IP address of the Session-
   Reflector behind the NAT, and detect changes in the NAT mapping that
   could cause sending the STAMP packets to the wrong Session-Reflector.

4.3.  Timestamp Information TLV

   The STAMP Session-Sender MAY include the Timestamp Information TLV to
   request information from the Session-Reflector.  The Session-Sender
   SHOULD NOT fill any information fields except for STAMP TLV Flags,
   Type, and Length.  The Session-Reflector MUST validate the Length
   value of the TLV.  If the value of the Length field is invalid, the
   Session-Reflector MUST zero all fields and MUST NOT return any
   information to the Session-Sender.

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |STAMP TLV Flags|Times Info Type|           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Sync. Src In | Timestamp In  | Sync. Src Out | Timestamp Out |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                    Figure 9: Timestamp Information TLV

   where fields are defined as the following:

   o  STAMP TLV Flags - is an eight-bit-long field.  Its format is
      presented in Figure 6.

   o  Timestamp Information Type - is a one-octet-long field, value TBA3
      allocated by IANA Section 5.1.

   o  Length - two-octet-long field, set equal to the value 4.

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   o  Sync Src In - one-octet-long field that characterizes the source
      of clock synchronization at the ingress of a Session-Reflector.
      There are several methods to synchronize the clock, e.g., Network
      Time Protocol (NTP) [RFC5905].  The value is one of those listed
      in Table 5.

   o  Timestamp In - one-octet-long field that characterizes the method
      by which the ingress of the Session-Reflector obtained the
      timestamp T2.  A timestamp may be obtained with hardware
      assistance, via software API from a local wall clock, or from a
      remote clock (the latter is referred to as "control plane").  The
      value is one of those listed in Table 7.

   o  Sync Src Out - one-octet-long field that characterizes the source
      of clock synchronization at the egress of the Session-Reflector.
      The value is one of those listed in Table 5.

   o  Timestamp Out - one-octet-long field that characterizes the method
      by which the egress of the Session-Reflector obtained the
      timestamp T3.  The value is one of those listed in Table 7.

4.4.  Class of Service TLV

   The STAMP Session-Sender MAY include a Class of Service (CoS) TLV in
   the STAMP test packet.  The format of the CoS TLV is presented in
   Figure 10.

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |STAMP TLV Flags|    CoS Type   |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   DSCP1   |   DSCP2   |ECN|            Reserved               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                      Figure 10: Class of Service TLV

   where fields are defined as the following:

   o  STAMP TLV Flags - is an eight-bit-long field.  Its format is
      presented in Figure 6.

   o  CoS (Class of Service) Type - is a one-octet-long field, value
      TBA4 allocated by IANA Section 5.1.

   o  Length - two-octet-long field, set equal to the value 4.

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   o  DSCP1 - The Differentiated Services Code Point (DSCP) intended by
      the Session-Sender to be used as the DSCP value of the reflected
      test packet.

   o  DSCP2 - The received value in the DSCP field at the Session-
      Reflector in the forward direction.

   o  ECN - The received value in the ECN field at the Session-Reflector
      in the forward direction.

   o  Reserved - 18-bit-long field, MUST be zeroed on transmission and
      ignored on receipt.

   A STAMP Session-Reflector that receives a test packet with the CoS
   TLV MUST include the CoS TLV in the reflected test packet.  Also, the
   Session-Reflector MUST copy the value of the DSCP and ECN fields of
   the IP header of the received STAMP test packet into the DSCP2 field
   in the reflected test packet.  Finally, the Session-Reflector MUST
   set the DSCP field's value in the IP header of the reflected test
   packet equal to the value of the DSCP1 field of the received test
   packet.  Upon receiving the reflected packet, the Session-Sender will
   save the DSCP and ECN values for analysis of the CoS in the reverse
   direction.

   Re-mapping of CoS can be used to provide multiple services (e,g., 2G,
   3G, LTE in mobile backhaul networks) over the same network.  But if
   it is misconfigured, then it is often difficult to diagnose the root
   cause of excessive packet drops of higher-level service while packet
   drops for lower service packets are at a normal level.  Using a CoS
   TLV in STAMP testing helps to troubleshoot the existing problem and
   also verify whether DiffServ policies are processing CoS as required
   by the configuration.

4.5.  Direct Measurement TLV

   The Direct Measurement TLV enables collection of the number of in-
   profile packets that had been transmitted and received by the
   Session-Sender and Session-Reflector, respectively.  The definition
   of "in-profile packet" is outside the scope of this document and is
   left to the test operators to determine.

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       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |STAMP TLV Flags|  Direct Type  |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              Session-Sender Tx counter  (S_TxC)               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             Session-Reflector Rx counter  (R_RxC)             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             Session-Reflector Tx counter  (R_TxC)             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 11: Direct Measurement TLV

   where fields are defined as the following:

   o  STAMP TLV Flags - is an eight-bit-long field.  Its format is
      presented in Figure 6.

   o  Direct (Measurement) Type - is a one-octet-long field, value TBA5
      allocated by IANA Section 5.1.

   o  Length - two-octet-long field equals length of the Value field in
      octets.  The Length field value MUST equal 12 octets.

   o  Session-Sender Tx counter (S_TxC) is a four-octet-long field.  The
      Session-Sender MUST set its value equal to the number of the
      transmitted in-profile packets.

   o  Session-Reflector Rx counter (R_RxC) is a four-octet-long field.
      MUST be zeroed by the Session-Sender on transmit and ignored by
      the Session-Reflector on receipt.  The Session-Reflector MUST fill
      it with the value of in-profile packets received.

   o  Session-Reflector Tx counter (R_TxC) is a four-octet-long field.
      MUST be zeroed by the Session-Sender and ignored by the Session-
      Reflector on receipt.  The Session-Reflector MUST fill it with the
      value of the transmitted in-profile packets.

   A Session-Sender MAY include the Direct Measurement TLV in a STAMP
   test packet.  The Session-Sender MUST zero the R_RxC and R_TxC fields
   before the transmission of the STAMP test packet.  If the received
   STAMP test packet includes the Direct Measurement TLV, the Session-
   Reflector MUST include it in the reflected test packet.  The Session-
   Reflector MUST copy the value from the S_TxC field of the received
   test packet into the same field of the reflected packet before its
   transmission.

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4.6.  Access Report TLV

   A STAMP Session-Sender MAY include an Access Report TLV (Figure 12)
   to indicate changes to the access network status to the Session-
   Reflector.  The definition of an access network is outside the scope
   of this document.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |STAMP TLV Flags|Acc Report Type|           Length              |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   ID  |  Resv |  Return Code  |          Reserved             |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                       Figure 12: Access Report TLV

   where fields are defined as follows:

   o  STAMP TLV Flags - is an eight-bit-long field.  Its format
      presented in Figure 6.

   o  Access Report Type - is a one-octet-long field, value TBA6
      allocated by IANA Section 5.1.

   o  Length - two-octet-long field, set equal to the value 4.

   o  ID (Access ID) - four-bit-long field that identifies the access
      network, e.g., 3GPP (Radio Access Technologies specified by 3GPP)
      or Non-3GPP (accesses that are not specified by 3GPP) [TS23501].
      The value is one of those listed below:

      *  1 - 3GPP Network

      *  2 - Non-3GPP Network

      All other values are invalid and the TLV that contains it MUST be
      discarded.

   o  Resv - four-bit-long field, MUST be zeroed on transmission and
      ignored on receipt.

   o  Return Code - one-octet-long field that identifies the report
      signal, e.g., available or unavailable.  The value is supplied to
      the STAMP end-point through some mechanism that is outside the
      scope of this document.  The value is one of those listed in
      Section 5.5.

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   o  Reserved - two-octet-long field, MUST be zeroed on transmission
      and ignored on receipt.

   The STAMP Session-Sender that includes the Access Report TLV sets the
   value of the Access ID field according to the type of access network
   it reports on.  Also, the Session-Sender sets the value of the Return
   Code field to reflect the operational state of the access network.
   The mechanism to determine the state of the access network is outside
   the scope of this specification.  A STAMP Session-Reflector that
   received the test packet with the Access Report TLV MUST include the
   Access Report TLV in the reflected test packet.  The Session-
   Reflector MUST set the value of the Access ID and Return Code fields
   equal to the values of the corresponding fields from the test packet
   it has received.

   The Session-Sender MUST also arm a retransmission timer after sending
   a test packet that includes the Access Report TLV.  This timer MUST
   be disarmed upon reception of the reflected STAMP test packet that
   includes the Access Report TLV.  In the event the timer expires
   before such a packet is received, the Session-Sender MUST retransmit
   the STAMP test packet that contains the Access Report TLV.  This
   retransmission SHOULD be repeated up to four times before the
   procedure is aborted.  Setting the value for the retransmission timer
   is based on local policies and network environment.  The default
   value of the retransmission timer for the Access Report TLV SHOULD be
   three seconds.  An implementation MUST provide control of the
   retransmission timer value and the number of retransmissions.

   The Access Report TLV is used by the Performance Measurement Function
   (PMF) components of the Access Steering, Switching and Splitting
   feature for 5G networks [TS23501].  The PMF component in the User
   Equipment acts as the STAMP Session-Sender, and the PMF component in
   the User Plane Function acts as the STAMP Session-Reflector.

4.7.  Follow-up Telemetry TLV

   A Session-Reflector might be able to put in the Timestamp field only
   an "SW Local" (see Table 7) timestamp.  But the hosting system might
   provide a timestamp closer to the start of the actual packet
   transmission even though it is not possible to deliver the
   information to the Session-Sender in time for the packet itself.
   This timestamp might nevertheless be important for the Session-
   Sender, as it improves the accuracy of measuring network delay by
   minimizing the impact of egress queuing delays on the measurement.

   A STAMP Session-Sender MAY include the Follow-up Telemetry TLV to
   request information from the Session-Reflector.  The Session-Sender
   MUST set the Follow-up Telemetry Type and Length fields to their

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   appropriate values.  The Sequence Number and Timestamp fields MUST be
   zeroed on transmission by the Session-Sender and ignored by the
   Session-Reflector upon receipt of the STAMP test packet that includes
   the Follow-up Telemetry TLV.  The Session-Reflector MUST validate the
   Length value of the STAMP test packet.  If the value of the Length
   field is invalid, the Session-Reflector MUST zero the Sequence Number
   and Timestamp fields and set the L flag in the STAMP TLV Flags field
   in the reflected packet.  If the Session-Reflector is in stateless
   mode (defined in Section 4.2 [RFC8762]), it MUST zero the Sequence
   Number and Timestamp fields.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |STAMP TLV Flags| Follow-up Type|           Length              |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                        Sequence Number                        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                      Follow-up Timestamp                      |
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Timestamp M  |                     Reserved                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                    Figure 13: Follow-up Telemetry TLV

   where fields are defined as follows:

   o  STAMP TLV Flags - is an eight-bit-long field.  Its format
      presented in Figure 6.

   o  Follow-up (Telemetry) Type - is a one-octet-long field, value TBA7
      allocated by IANA Section 5.1.

   o  Length - two-octet-long field, set equal to the value 16 octets.

   o  Sequence Number - four-octet-long field indicating the sequence
      number of the last packet reflected in the same STAMP-test
      session.  Since the Session-Reflector runs in the stateful mode
      (defined in Section 4.2 [RFC8762]), it is the Session-Reflector's
      Sequence Number of the previous reflected packet.

   o  Follow-up Timestamp - eight-octet-long field, with the format
      indicated by the Z flag of the Error Estimate field of the packet
      transmitted by a Session-Reflector, as described in Section 4.1
      [RFC8762].  It carries the timestamp when the reflected packet
      with the specified sequence number was sent.

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   o  Timestamp M(ode) - one-octet-long field that characterizes the
      method by which the entity that transmits a reflected STAMP packet
      obtained the Follow-up Timestamp.  The value is one of those
      listed in Table 7.

   o  Reserved - three-octet-long field.  Its value MUST be zeroed on
      transmission and ignored on receipt.

4.8.  HMAC TLV

   The STAMP authenticated mode protects the integrity of data collected
   in the STAMP base packet.  STAMP extensions are designed to provide
   valuable information about the condition of a network, and protecting
   the integrity of that data is also essential.  The keyed Hashed
   Message Authentication Code (HMAC) TLV MUST be included in a STAMP
   test packet in the authenticated mode, excluding when the only TLV
   present is Extra Padding TLV.  The HMAC TLV MUST follow all TLVs
   included in a STAMP test packet, except for the Extra Padding TLV.
   The HMAC TLV MAY be used to protect the integrity of STAMP extensions
   in STAMP unauthenticated mode.

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |STAMP TLV Flags|   HMAC Type   |             Length            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      |                              HMAC                             |
      |                                                               |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                            Figure 14: HMAC TLV

   where fields are defined as follows:

   o  STAMP TLV Flags - is an eight-bit-long field.  Its format is
      presented in Figure 6.

   o  HMAC Type - is a one-octet-long field, value TBA8 allocated by
      IANA Section 5.1.

   o  Length - two-octet-long field, set equal to 16 octets.

   o  HMAC - is a 16-octet-long field that carries HMAC digest of the
      text of all preceding TLVs.

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   As defined in [RFC8762], STAMP uses HMAC-SHA-256 truncated to 128
   bits ([RFC4868]).  All considerations regarding using the key and key
   distribution and management listed in Section 4.4 of [RFC8762] are
   fully applicable to the use of the HMAC TLV.  HMAC is calculated as
   defined in [RFC2104] over text as the concatenation of all preceding
   TLVs.  The digest then MUST be truncated to 128 bits and written into
   the HMAC field.  In the authenticated mode, HMAC MUST be verified
   before using any data in the included STAMP TLVs.  If HMAC
   verification by the Session-Reflector fails, then the Session-
   Reflector MUST stop processing the received extended STAMP test
   packet.  The Session-Reflector MUST copy the remainder of the
   extended STAMP test packet into the reflected packet.  The Session-
   Reflector MUST set the A flag in the copy of the HMAC TLV in the
   reflected packet to 1 before transmitting the reflected test packet.
   Also, both the Session-Sender and Session-Reflector SHOULD log the
   notification that HMAC verification of STAMP TLVs failed.

5.  IANA Considerations

5.1.  STAMP TLV Registry

   IANA is requested to create the STAMP TLV Type registry.  All code
   points in the range 1 through 175 in this registry shall be allocated
   according to the "IETF Review" procedure as specified in [RFC8126].
   Code points in the range 176 through 239 in this registry shall be
   allocated according to the "First Come First Served" procedure as
   specified in [RFC8126].  The remaining code points are allocated
   according to Table 1:

          +-----------+--------------+-------------------------+
          | Value     | Description  | Reference               |
          +-----------+--------------+-------------------------+
          | 0         |   Reserved   | This document           |
          | 1- 175    |  Unassigned  | IETF Review             |
          | 176 - 239 |  Unassigned  | First Come First Served |
          | 240 - 251 | Experimental | This document           |
          | 252 - 254 | Private Use  | This document           |
          | 255       |   Reserved   | This document           |
          +-----------+--------------+-------------------------+

                     Table 1: STAMP TLV Type Registry

   This document defines the following new values in the STAMP Extension
   TLV range of the STAMP TLV Type registry:

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             +-------+-----------------------+---------------+
             | Value |      Description      | Reference     |
             +-------+-----------------------+---------------+
             | TBA1  |     Extra Padding     | This document |
             | TBA2  |        Location       | This document |
             | TBA3  | Timestamp Information | This document |
             | TBA4  |    Class of Service   | This document |
             | TBA5  |   Direct Measurement  | This document |
             | TBA6  |     Access Report     | This document |
             | TBA7  |  Follow-up Telemetry  | This document |
             | TBA8  |          HMAC         | This document |
             +-------+-----------------------+---------------+

                           Table 2: STAMP Types

5.2.  STAMP TLV Flags Sub-registry

   IANA is requested to create the STAMP TLV Flags sub-registry as part
   of the STAMP TLV Type registry.  The registration procedure is "IETF
   Review" [RFC8126].  Flags are 8 bits.  This document defines the
   following bit positions in the STAMP TLV Flags sub-registry:

     +--------------+--------+-----------------------+---------------+
     | Bit position | Symbol |      Description      |   Reference   |
     +--------------+--------+-----------------------+---------------+
     |      0       |   U    |    Unrecognized TLV   | This document |
     |      1       |   L    |     Malformed TLV     | This document |
     |      2       |   A    | Authentication failed | This document |
     +--------------+--------+-----------------------+---------------+

                         Table 3: STAMP TLV Flags

5.3.  Synchronization Source Sub-registry

   IANA is requested to create the Synchronization Source sub-registry
   as part of the STAMP TLV Type registry.  All code points in the range
   1 through 127 in this registry shall be allocated according to the
   "IETF Review" procedure as specified in [RFC8126].  Code points in
   the range 128 through 239 in this registry shall be allocated
   according to the "First Come First Served" procedure as specified in
   [RFC8126].  Remaining code points are allocated according to Table 4:

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          +-----------+--------------+-------------------------+
          | Value     | Description  | Reference               |
          +-----------+--------------+-------------------------+
          | 0         |   Reserved   | This document           |
          | 1- 127    |  Unassigned  | IETF Review             |
          | 128 - 239 |  Unassigned  | First Come First Served |
          | 240 - 249 | Experimental | This document           |
          | 250 - 254 | Private Use  | This document           |
          | 255       |   Reserved   | This document           |
          +-----------+--------------+-------------------------+

               Table 4: Synchronization Source Sub-registry

   This document defines the following new values in the Synchronization
   Source sub-registry:

            +-------+-------------------------+---------------+
            | Value |       Description       | Reference     |
            +-------+-------------------------+---------------+
            | 1     |           NTP           | This document |
            | 2     |           PTP           | This document |
            | 3     |         SSU/BITS        | This document |
            | 4     | GPS/GLONASS/LORAN-C/BDS | This document |
            | 5     |    Local free-running   | This document |
            +-------+-------------------------+---------------+

                     Table 5: Synchronization Sources

5.4.  Timestamping Method Sub-registry

   IANA is requested to create the Timestamping Method sub-registry as
   part of the STAMP TLV Type registry.  All code points in the range 1
   through 127 in this registry shall be allocated according to the
   "IETF Review" procedure as specified in [RFC8126].  Code points in
   the range 128 through 239 in this registry shall be allocated
   according to the "First Come First Served" procedure as specified in
   [RFC8126].  Remaining code points are allocated according to Table 6:

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          +-----------+--------------+-------------------------+
          | Value     | Description  | Reference               |
          +-----------+--------------+-------------------------+
          | 0         |   Reserved   | This document           |
          | 1- 127    |  Unassigned  | IETF Review             |
          | 128 - 239 |  Unassigned  | First Come First Served |
          | 240 - 249 | Experimental | This document           |
          | 250 - 254 | Private Use  | This document           |
          | 255       |   Reserved   | This document           |
          +-----------+--------------+-------------------------+

                 Table 6: Timestamping Method Sub-registry

   This document defines the following new values in the Timestamping
   Methods sub-registry:

                 +-------+---------------+---------------+
                 | Value |  Description  | Reference     |
                 +-------+---------------+---------------+
                 | 1     |   HW Assist   | This document |
                 | 2     |    SW local   | This document |
                 | 3     | Control plane | This document |
                 +-------+---------------+---------------+

                       Table 7: Timestamping Methods

5.5.  Return Code Sub-registry

   IANA is requested to create the Return Code sub-registry as part of
   the STAMP TLV Type registry.  All code points in the range 1 through
   127 in this registry shall be allocated according to the "IETF
   Review" procedure as specified in [RFC8126].  Code points in the
   range 128 through 239 in this registry shall be allocated according
   to the "First Come First Served" procedure as specified in [RFC8126].
   Remaining code points are allocated according to Table 8:

          +-----------+--------------+-------------------------+
          | Value     | Description  | Reference               |
          +-----------+--------------+-------------------------+
          | 0         |   Reserved   | This document           |
          | 1- 127    |  Unassigned  | IETF Review             |
          | 128 - 239 |  Unassigned  | First Come First Served |
          | 240 - 249 | Experimental | This document           |
          | 250 - 254 | Private Use  | This document           |
          | 255       |   Reserved   | This document           |
          +-----------+--------------+-------------------------+

                     Table 8: Return Code Sub-registry

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   This document defines the following new values in the Return Code
   sub-registry:

              +-------+---------------------+---------------+
              | Value |     Description     | Reference     |
              +-------+---------------------+---------------+
              | 1     |  Network available  | This document |
              | 2     | Network unavailable | This document |
              +-------+---------------------+---------------+

                           Table 9: Return Codes

6.  Security Considerations

   This document defines extensions to STAMP [RFC8762] and inherits all
   the security considerations applicable to the base protocol.
   Additionally, the HMAC TLV is defined in this document to protect the
   integrity of optional STAMP extensions.  The use of HMAC TLV is
   discussed in detail in Section 4.8.

7.  Acknowledgments

   Authors much appreciate the thorough review and thoughtful comments
   received from Tianran Zhou, Rakesh Gandhi, Yuezhong Song and Yali
   Wang.  The authors express their gratitude to Al Morton for his
   comments and the most valuable suggestions.  The authors greatly
   appreciate comments and thoughtful suggestions received from Martin
   Duke.

8.  Contributors

   The following people contributed text to this document:

      Guo Jun
      ZTE Corporation
      68# Zijinghua Road
      Nanjing, Jiangsu  210012
      P.R.China

      Phone: +86 18105183663
      Email: guo.jun2@zte.com.cn

9.  References

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9.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC5357]  Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
              Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
              RFC 5357, DOI 10.17487/RFC5357, October 2008,
              <https://www.rfc-editor.org/info/rfc5357>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8762]  Mirsky, G., Jun, G., Nydell, H., and R. Foote, "Simple
              Two-Way Active Measurement Protocol", RFC 8762,
              DOI 10.17487/RFC8762, March 2020,
              <https://www.rfc-editor.org/info/rfc8762>.

   [TS23501]  3GPP (3rd Generation Partnership Project), "Technical
              Specification Group Services and System Aspects; System
              Architecture for the 5G System; Stage 2 (Release 16)",
              3GPP TS23501, 2019.

9.2.  Informative References

   [GPS]      "Global Positioning System (GPS) Standard Positioning
              Service (SPS) Performance Standard", GPS SPS 5th Edition,
              April 2020.

   [IEEE.1588.2008]
              "Standard for a Precision Clock Synchronization Protocol
              for Networked Measurement and Control Systems",
              IEEE Standard 1588, March 2008.

   [RFC2104]  Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-
              Hashing for Message Authentication", RFC 2104,
              DOI 10.17487/RFC2104, February 1997,
              <https://www.rfc-editor.org/info/rfc2104>.

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   [RFC4868]  Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA-
              384, and HMAC-SHA-512 with IPsec", RFC 4868,
              DOI 10.17487/RFC4868, May 2007,
              <https://www.rfc-editor.org/info/rfc4868>.

   [RFC5905]  Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch,
              "Network Time Protocol Version 4: Protocol and Algorithms
              Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010,
              <https://www.rfc-editor.org/info/rfc5905>.

Authors' Addresses

   Greg Mirsky
   ZTE Corp.

   Email: gregimirsky@gmail.com

   Xiao Min
   ZTE Corp.

   Email: xiao.min2@zte.com.cn

   Henrik Nydell
   Accedian Networks

   Email: hnydell@accedian.com

   Richard Foote
   Nokia

   Email: footer.foote@nokia.com

   Adi Masputra
   Apple Inc.
   One Apple Park Way
   Cupertino, CA  95014
   USA

   Email: adi@apple.com

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   Ernesto Ruffini
   OutSys
   via Caracciolo, 65
   Milano  20155
   Italy

   Email: eruffini@outsys.org

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