Network Working Group                                          G. Mirsky
Internet-Draft                                                    X. Min
Intended status: Standards Track                               ZTE Corp.
Expires: January 7, 2020                                          G. Jun
                                                         ZTE Corporation
                                                               H. Nydell
                                                       Accedian Networks
                                                                R. Foote
                                                                   Nokia
                                                            July 6, 2019


     Simple Two-way Active Measurement Protocol Optional Extensions
                 draft-mirsky-ippm-stamp-option-tlv-05

Abstract

   This document describes optional extensions to Simple Two-way Active
   Measurement Protocol (STAMP) which enable measurement performance
   metrics in addition to ones supported by the STAMP base
   specification.

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 7, 2020.

Copyright Notice

   Copyright (c) 2019 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



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   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 . . . . . . . . . . . . . .   2
     2.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   2
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   3.  Theory of Operation . . . . . . . . . . . . . . . . . . . . .   3
   4.  TLV Extensions to STAMP . . . . . . . . . . . . . . . . . . .   4
     4.1.  Extra Padding TLV . . . . . . . . . . . . . . . . . . . .   6
     4.2.  Location TLV  . . . . . . . . . . . . . . . . . . . . . .   6
     4.3.  Timestamp Information TLV . . . . . . . . . . . . . . . .   8
     4.4.  Class of Service TLV  . . . . . . . . . . . . . . . . . .   9
     4.5.  Direct Measurement TLV  . . . . . . . . . . . . . . . . .  10
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
     5.1.  STAMP TLV Registry  . . . . . . . . . . . . . . . . . . .  11
     5.2.  Synchronization Source Sub-registry . . . . . . . . . . .  12
     5.3.  Timestamping Method Sub-registry  . . . . . . . . . . . .  13
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  14
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  14
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  14
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  15
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15

1.  Introduction

   Simple Two-way Active Measurement Protocol (STAMP)
   [I-D.ietf-ippm-stamp] supports the use of optional extensions that
   use Type-Length-Value (TLV) encoding.  Such extensions are to enhance
   the STAMP base functions, such as measurement of one-way and round-
   trip delay, latency, packet loss, as well as ability to detect packet
   duplication and out-of-order delivery of the test packets.  This
   specification provides definitions of optional STAMP extensions,
   their formats, and theory of operation.

2.  Conventions used in this document

2.1.  Terminology

   STAMP - Simple Two-way Active Measurement Protocol

   DSCP - Differentiated Services Code Point



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   ECN - Explicit Congestion Notification

   NTP - Network Time Protocol

   PTP - Precision Time Protocol

   HMAC Hashed Message Authentication Code

   TLV Type-Length-Value

   BITS Building Integrated Timing Supply

   SSU Synchronization Supply Unit

   GPS Global Positioning System

   GLONASS Global Orbiting Navigation Satellite System

   LORAN-C Long Range Navigation System Version C

   MBZ Must Be Zeroed

   CoS Class of Service

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.

3.  Theory of Operation

   STAMP Session-Sender transmits test packets to STAMP Session-
   Reflector.  STAMP Session-Reflector receives 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] packet formats.

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



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4.  TLV Extensions to STAMP

   Figure 1 displays the format of STAMP Session-Sender test packet in
   unauthenticated mode that includes a 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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Sequence Number                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Timestamp                            |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         Error Estimate        |                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               |
      |                                                               |
      |                                                               |
      |                         MBZ (30 octets)                       |
      |                                                               |
      |                                                               |
      |                                                               |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             Type              |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                            Value                              ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       Figure 1: STAMP Session-Sender test packet format with TLV in
                           unauthenticated mode

   The MBZ (Must Be Zeroed) field of a test packet transmitted by a
   STAMP Session-Sender MUST be 30 octets long.  A STAMP Session-Sender
   test packet MUST NOT use the Reflect Octets capability defined in
   [RFC6038].

   TLVs (Type-Length-Value tuples) have the two octets long Type field,
   two octets long Length field that is the length of the Value field in
   octets.  Type values, see Section 5.1, less than 32768 identify
   mandatory TLVs that MUST be supported by an implementation.  Type
   values greater than or equal to 32768 identify optional TLVs that
   SHOULD be ignored if the implementation does not understand or
   support them.  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 Number, in network octet order.  The rest of
   the Value field is private to the vendor.  Following sections




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   describe the use of TLVs for STAMP that extend STAMP capability
   beyond its base specification.

   Figure 2 displays the format of STAMP Session-Reflector test packet
   in unauthenticated mode that includes a 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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                        Sequence Number                        |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                          Timestamp                            |
    |                                                               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |         Error Estimate        |           MBZ                 |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                          Receive Timestamp                    |
    |                                                               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                 Session-Sender Sequence Number                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                  Session-Sender Timestamp                     |
    |                                                               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    | Session-Sender Error Estimate |           MBZ                 |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |Ses-Sender TTL |                  MBZ2                         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |             Type              |           Length              |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    ~                            Value                              ~
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     Figure 2: STAMP Session-Reflector test packet format with TLV in
                           unauthenticated mode

   The MBZ2 field of a test packet transmitted by a STAMP Session-
   Reflector MUST be 3 octets long.

   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 UDP
   header, then the test packet includes one or more STAMP TLVs that
   immediately follow the base STAMP test packet.



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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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |      Extra Padding Type       |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      ~                         Extra Padding                         ~
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                        Figure 3: Extra Padding TLV

   where fields are defined as the following:

   o  Extra Padding Type - TBA1 allocated by IANA Section 5.1

   o  Length - 2 octets long field equals length on the Extra Padding
      field in octets.

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

   The Extra Padding TLV is similar to the Packet Padding field in
   TWAMP-Test packet [RFC5357].  The in STAMP the Packet Padding field
   is used to ensure symmetrical size between Session-Sender and
   Session-Reflector test packets.  Extra Padding TLV MUST be used to
   create STAMP test packets of larger size.

4.2.  Location TLV

   STAMP session-sender MAY include the Location TLV to request
   information from the session-reflector.  The session-sender SHOULD
   NOT fill any information fields except for Type and Length.  The
   session-reflector MUST validate the Length value against the address
   family of the transport encapsulating the STAMP test packet.  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.
   The session-reflector MUST ignore all other fields of the received
   Location TLV.










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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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |          Location Type        |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Source MAC                           |
      +                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                               |           Reserved A          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                    Destination IP Address                     ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                       Source IP Address                       ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Dest.port   |   Src.Port    |          Reserved B           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                 Figure 4: Session-Reflector Location TLV

   where fields are defined as the following:

   o  Location Type - TBA2 allocated by IANA Section 5.1

   o  Length - 2 octets long field equals length on the Value field in
      octets.  Length field value MUST be 20 octets for the IPv4 address
      family.  For the IPv6 address family value of the Length field
      MUST be 44 octets.  All other values are invalid.

   o  Source MAC - 6 octets 48 bits long field.  The session-reflector
      MUST copy Source MAC of received STAMP packet into this field.

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

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

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

   o  Dest.port - one octet long UDP destination port number of the
      received STAMP packet.

   o  Src.port - one octet long UDP source port number of the received
      STAMP packet.

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




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   The Location TLV MAY be used to determine the last-hop addressing for
   STAMP packets including source and destination IP addresses as well
   as the MAC address of the last-hop router.  Last-hop MAC address MAY
   be monitored by the Session-Sender whether there has been a path
   switch on the last hop, closest to the Session-Reflector.  The IP
   addresses and UDP port will indicate if there is a NAT router on the
   path, and allows the Session-Sender to identify the IP address of the
   Session-Reflector behind the NAT, detect changes in the NAT mapping
   that could cause sending the STAMP packets to the wrong Session-
   Reflector.

4.3.  Timestamp Information TLV

   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 Type and Length.
   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 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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Timestamp Information Type   |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Sync. Src In | Timestamp In  | Sync. Src Out | Timestamp Out |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                    Figure 5: Timestamp Information TLV

   where fields are defined as the following:

   o  Timestamp Information Type - TBA3 allocated by IANA Section 5.1

   o  Length - 2 octets long field, equals four octets.

   o  Sync Src In - one octet long field that characterizes the source
      of clock synchronization at the ingress of Session-Reflector.
      There are several of methods to synchronize the clock, e.g.,
      Network Time Protocol (NTP) [RFC5905], Precision Time Protocol
      (PTP) [IEEE.1588.2008], Synchronization Supply Unit (SSU) or
      Building Integrated Timing Supply (BITS), or Global Positioning
      System (GPS), Global Orbiting Navigation Satellite System
      (GLONASS) and Long Range Navigation System Version C (LORAN-C).
      The value is one of Section 5.2.





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   o  Timestamp In - one octet long field that characterizes the method
      by which the ingress of Session-Reflector obtained the timestamp
      T2.  A timestamp may be obtained with hardware assist, via
      software API from a local wall clock, or from a remote clock (the
      latter referred to as "control plane").  The value is one of
      Section 5.3.

   o  Sync Src Out - one octet long field that characterizes the source
      of clock synchronization at the egress of Session-Reflector.  The
      value is one of Section 5.2.

   o  Timestamp Out - one octet long field that characterizes the method
      by which the egress of Session-Reflector obtained the timestamp
      T3.  The value is one of Section 5.3.

4.4.  Class of Service TLV

   The STAMP session-sender MAY include Class of Service (CoS) TLV in
   the STAMP test packet.  If the CoS TLV is present in the STAMP test
   packet and the value of the DSCP1 field is zero, then the STAMP
   session-reflector MUST copy the values of Differentiated Services
   Code Point (DSCP) ECN fields from the received STAMP test packet into
   DSCP2 and ECN fields respectively of the CoS TLV of the reflected
   STAMP test packet.  If the value of the DSCP1 field is non-zero, then
   the STAMP session-reflector MUST use DSCP1 value from the CoS TLV in
   the received STAMP test packet as DSCP value of STAMP reflected test
   packet and MUST copy DSCP and ECN values of the received STAMP test
   packet into DSCP2 and ECN fields of Class of Service TLV in the STAMP
   reflected a packet.  The Session-Sender, upon receiving the reflected
   packet, will save the DSCP and ECN values for analysis of the CoS in
   the reverse direction.

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |      Class of Service Type    |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   DSCP1   |   DSCP2   |ECN|            Reserved               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                      Figure 6: Class of Service TLV

   where fields are defined as the following:

   o  Class of Service Type - TBA4 allocated by IANA Section 5.1

   o  Length - 2 octets long field, equals four octets.




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   o  DSCP1 - The Differentiated Services Code Point (DSCP) intended by
      the Session-Sender.  To be used as the return DSCP from the
      Session-Reflector.

   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 bits long field, must be zeroed in transmission and
      ignored on receipt.

   A STAMP Session-Sender that includes the CoS TLV sets the value of
   the DSCP1 field and zeroes the value of the DSCP2 field.  A STAMP
   Session-Reflector that received the 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 field of the IP header of
   the received STAMP test packet into the DSCP2 field in the reflected
   test packet.  And, at last, the Session-Reflector MUST set the value
   of the DSCP field in the IP header of the reflected test packet equal
   to the value of the DSCP1 field of the test packet it has received.

   Re-mapping of CoS in some use cases, for example, in mobile backhaul
   networks is used to provide multiple services, i.e., 2G, 3G, LTE,
   over the same network.  But if it is misconfigured, then it is often
   difficult to diagnose the root cause of the problem that is viewed as
   an excessive packet drop of higher level service while packet drop
   for lower service packets is at a normal level.  Using CoS TLV in
   STAMP test 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 "in profile" IP
   packets that had been transmitted and received by the Session-Sender
   and Session-Reflector respectfully.  The definition of "in-profile
   packet" is outside the scope of this document.












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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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    Direct Measurement Type    |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              Session-Sender Tx counter  (S_TxC)               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             Session-Reflector Rx counter  (R_RxC)             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             Session-Reflector Tx counter  (R_TxC)             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 7: Direct Measurement TLV

   where fields are defined as the following:

   o  Direct Measurement Type - TBA5 allocated by IANA Section 5.1

   o  Length - 2 octets long field equals length on the Value field in
      octets.  Length field value MUST be 12 octets.

   o  Session-Sender Tx counter (S_TxC) is four octets long field.

   o  Session-Reflector Rx counter (R_RxC) is four octets long field.
      MUST be zeroed by the Session-Sender and filled by the Session-
      Reflector.

   o  Session-Reflector Tx counter (R_TxC) is four octets long field.
      MUST be zeroed by the Session-Sender and filled by the Session-
      Reflector.

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 32759 in this registry shall be
   allocated according to the "IETF Review" procedure as specified in
   [RFC8126].  Code points in the range 32760 through 65279 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 1:









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   +---------------+-------------------------+-------------------------+
   | Value         |       Description       | Reference               |
   +---------------+-------------------------+-------------------------+
   | 0             |         Reserved        | This document           |
   | 1- 32767      |      Mandatory TLV,     | IETF Review             |
   |               |        unassigned       |                         |
   | 32768 - 65279 |      Optional TLV,      | First Come First Served |
   |               |        unassigned       |                         |
   | 65280 - 65519 |       Experimental      | This document           |
   | 65520 - 65534 |       Private Use       | This document           |
   | 65535         |         Reserved        | This document           |
   +---------------+-------------------------+-------------------------+

                     Table 1: STAMP TLV Type Registry

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

             +-------+-----------------------+---------------+
             | 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 |
             +-------+-----------------------+---------------+

                           Table 2: STAMP Types

5.2.  Synchronization Source Sub-registry

   IANA is requested to create Synchronization Source sub-registry as
   part of 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 1:












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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 3: Synchronization Source Sub-registry

   This document defines the following new values in 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 | This document |
              | 5     |  Local free-running | This document |
              +-------+---------------------+---------------+

                     Table 4: Synchronization Sources

5.3.  Timestamping Method Sub-registry

   IANA is requested to create Timestamping Method sub-registry as part
   of 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 1:














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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 5: Timestamping Method Sub-registry

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

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

                       Table 6: Timestamping Methods

6.  Security Considerations

   Use of HMAC in authenticated mode may be used to simultaneously
   verify both the data integrity and the authentication of the STAMP
   test packets.

7.  Acknowledgments

   Authors much appreciate the thorough review and thoughful comments
   received from Tianran Zhou.

8.  References

8.1.  Normative References

   [I-D.ietf-ippm-stamp]
              Mirsky, G., Jun, G., Nydell, H., and R. Foote, "Simple
              Two-way Active Measurement Protocol", draft-ietf-ippm-
              stamp-06 (work in progress), April 2019.






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   [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>.

   [RFC6038]  Morton, A. and L. Ciavattone, "Two-Way Active Measurement
              Protocol (TWAMP) Reflect Octets and Symmetrical Size
              Features", RFC 6038, DOI 10.17487/RFC6038, October 2010,
              <https://www.rfc-editor.org/info/rfc6038>.

   [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>.

8.2.  Informative References

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

   [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



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

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


   Henrik Nydell
   Accedian Networks

   Email: hnydell@accedian.com


   Richard Foote
   Nokia

   Email: footer.foote@nokia.com































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