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IP Flow Information Export (IPFIX) Alternate-Marking Information Elements
draft-ietf-opsawg-ipfix-alt-mark-07

Document Type Active Internet-Draft (opsawg WG)
Authors Thomas Graf , Giuseppe Fioccola , Tianran Zhou , Yongqing Zhu
Last updated 2026-07-28
Replaces draft-gfz-opsawg-ipfix-alt-mark
RFC stream Internet Engineering Task Force (IETF)
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Dec 2025
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draft-ietf-opsawg-ipfix-alt-mark-07
OPSAWG                                                           T. Graf
Internet-Draft                                                  Swisscom
Intended status: Standards Track                             G. Fioccola
Expires: 30 January 2027                                         T. Zhou
                                                                  Huawei
                                                                  Y. Zhu
                                                           China Telecom
                                                            29 July 2026

    IP Flow Information Export (IPFIX) Alternate-Marking Information
                                Elements
                  draft-ietf-opsawg-ipfix-alt-mark-07

Abstract

   This document specifies the IP Flow Information Export (IPFIX)
   Information Elements (IEs) to export Alternate Marking measurement
   data.

Status of This Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
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   Internet-Drafts are draft documents valid for a maximum of six months
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   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 30 January 2027.

Copyright Notice

   Copyright (c) 2026 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 Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   2.  AltMark IPFIX Information Elements  . . . . . . . . . . . . .   3
     2.1.  Flow Aggregation  . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Flow Correlation  . . . . . . . . . . . . . . . . . . . .   4
     2.3.  Flow Measurements . . . . . . . . . . . . . . . . . . . .   5
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
     3.1.  altmarkFlowMonID  . . . . . . . . . . . . . . . . . . . .   7
     3.2.  Loss flag . . . . . . . . . . . . . . . . . . . . . . . .   7
     3.3.  Delay flag  . . . . . . . . . . . . . . . . . . . . . . .   8
     3.4.  Period Number . . . . . . . . . . . . . . . . . . . . . .   8
   4.  Operational Considerations  . . . . . . . . . . . . . . . . .   8
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   9
   7.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .   9
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  10
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  11
   Appendix A.  AltMark Examples . . . . . . . . . . . . . . . . . .  12
     A.1.  Loss Measurement Flow Record  . . . . . . . . . . . . . .  12
     A.2.  Delay Measurement Flow Record . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   Alternate-Marking Method (AltMark) [RFC9341] [RFC9342] is a technique
   used to measure packet loss, delay, and jitter on in-flight packets.

   [I-D.ietf-ippm-alt-mark-deployment] provides a framework for
   Alternate Marking deployments and includes considerations and
   guidance for application and methodology.  The IP Flow Information
   Export (IPFIX) protocol [RFC7011] [RFC7012] is considered for data
   export in Section 6.1 of [I-D.ietf-ippm-alt-mark-deployment].

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   [RFC7012] defines the data types and management policy for the
   information model of the IPFIX protocol [RFC7011].  This document
   defines the new IPFIX Information Elements (IEs) for the Alternate
   Marking Method.

1.1.  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.

2.  AltMark IPFIX Information Elements

   This section describes existing Information Elements (IEs)
   [IANA-IPFIX] that are relevant for the Alternate Marking application
   and also introduces new IEs.

   With AltMark [RFC9341] [RFC9342], each node needs to export the
   packet counters and timestamps at each period for the monitored flow,
   according to AltMark operation.  To identify and export telemetry
   data for an AltMark monitored flow, it is needed a combination of
   already existing IEs and new IEs, which are introduced in this
   document.  A flow can be identified using IEs such as source address,
   destination address, protocol and ports.  But, according to [RFC9343]
   and its AltMark protocol extensions, it is also necessary to define
   new IEs (the flow identifier FlowMonID, the Period Number, the Loss
   flag and the Delay flag) to complete the AltMark information to be
   exported.

2.1.  Flow Aggregation

   To use IPFIX for exporting AltMark data, it is necessary to aggregate
   AltMark flows, according to Section 5 of [RFC7015].  As mentioned
   above, the export of the AltMark data should be realized based on the
   fields defined in the specific protocol extension.

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   For IPv6, the AltMark Extension Header Option, described in
   Section 3.1 of [RFC9343], or the Segment Routing Header TLV,
   described in Section 3.1 of [RFC9947], contains the FlowMonID, Loss
   and Delay flag, that need to be used for data aggregation.  The
   existing Information Element (IE) that could be employed is
   ipPayloadPacketSection(IE314), defined in Section 4.2 of [RFC7133],
   because any extension header present is considered part of the
   payload.  However, ipPayloadPacketSection should be decomposed to
   export the relevant data, that need to be extracted, parsed, and
   exposed from the ipPayloadPacketSection.  For this reason, the use of
   the existing IEs is not the best option and, therefore, this document
   introduces a better approach by defining new IEs.

   New IPFIX Information Elements are needed so that the data can now be
   aggregated easily.  The new IEs defined in this document are:
   altmarkFlowMonID (TBD1), altmarkLossFlag (TBD2) and altmarkDelayFlag
   (TBD3).  Therefore altmarkFlowMonID, altmarkLossFlag and
   altmarkDelayFlag are Flow Key fields for the AltMark flow
   aggregation.

2.2.  Flow Correlation

   The following IPFIX IEs can be used to describe the flow on the
   different nodes:

   *  ingressInterface(IE10)

   *  egressInterface(IE14)

   *  sourceIPv4Address(IE8) or sourceIPv6Address(IE27)

   *  sourceTransportPort(IE7)

   *  destinationIPv4Address(IE12) or destinationIPv6Address(IE28)

   *  destinationTransportPort(IE11)

   *  protocolIdentifier(IE4)

   In addition to the existing IEs above, the new IEs defined in this
   document are also added for the AltMark monitored flows.

   *  altmarkFlowMonID (TBD1)

   *  altmarkLossFlag (TBD2)

   *  altmarkDelayFlag (TBD3)

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   Note that, in case of Link Aggregation Group (LAG) interface, the
   ingressInterface IE and egressInterface IE can be used to refer the
   logical LAG port, while ingressPhysicalInterface IE and
   egressPhysicalInterface IE can be used to indicate the physical
   interfaces which are members of the LAG port.

2.3.  Flow Measurements

   [I-D.ietf-ippm-alt-mark-deployment] describes how to manage and
   deploy the AltMark method and IPFIX can be used to export the
   telemetry data to the Network Management System (NMS).

   An Alternate-Marking Domain consists of marking nodes, unmarking
   nodes, and transit nodes.  These nodes are all IPFIX Observation
   Points, while the IPFIX Observation Domain is the AltMark measurement
   domain.

   As specified in the previous sections, the Flow Keys used to define a
   flow are, at minimum, altmarkFlowMonID (TBD1), altmarkLossFlag (TBD2)
   and altmarkDelayFlag (TBD3).  The traditional '5-tuple' Flow Key of
   source and destination IP address, source and destination transport
   port, and transport protocol can be selected as additional Flow Keys,
   next to the altmarkFlowMonID, altmarkLossFlag and altmarkDelayFlag.

   The AltMark Flows are defined separately for loss measurements and
   delay measurements.  In particular, the flow for loss measurements
   can be identified by the altmarkFlowMonID, the altmarkLossFlag (and
   potentially the extra Key Fields, if configured); while the flow for
   delay measurements can be identified by the altmarkFlowMonID, the
   altmarkDelayFlag (and potentially the extra Key Fields, if
   configured).

   [I-D.ietf-ippm-alt-mark-deployment] also introduces the
   altmarkPeriodNumber (TBD4), which is needed for Alternate-Marking
   measurement correlation.

   The Flow Record, which is observed at each Observation Point,
   contains the characteristic properties of the Flow together with the
   measured properties (i.e., packet count and timestamps).
   Furthermore, as specified in [I-D.ietf-ippm-alt-mark-deployment], the
   altmarkPeriodNumber (TBD4) is calculated on each Observation Point as
   the modulo of the local time and the interval of the marking time
   period.  The altmarkPeriodNumber is associated to each Flow Record.

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   Together with the Key Fields, the Flow Records typically export the
   altmarkPeriodNumber and the packetDeltaCount(IE2) for the loss
   measurement, while they typically export the altmarkPeriodNumber and
   the flowStartMicroseconds(IE154), flowEndMicroseconds(IE155) for the
   delay measurements.

   The AltMark marking, transit and unmarking nodes can be Exporters and
   export the data record.  The periodicity or export policy is
   configurable and it must be in line with the AltMark period, as
   specified in [I-D.ietf-ippm-alt-mark-deployment].

   There are two options for the computation:

      The NMS acts as Collector.  The loss and delay metrics are
      computed on the NMS by comparing the packet counts and timestamps
      at each AltMark period, according to the AltMark technique
      [RFC9341] [RFC9342].

      The computation of loss or delay metrics can be done directly on
      the node.  Indeed, according to [RFC9951], it is possible to
      export the delay performance metrics in IPFIX.  Therefore,
      assuming we have the counter and timestamp information directly on
      the node, as enabled by [RFC9947], the delay can be computed on
      the router.

   To calculate loss, the packet count can be based upon
   octetDeltaCount(IE1) or packetDeltaCount(IE2).

   To calculate delay, either flowStartSeconds(IE150),
   flowStartMilliseconds(IE152), flowStartMicroseconds(IE154) or
   flowStartNanoseconds(IE156), can be used depending on timestamp
   granularity requirements.  It is also possible to use
   flowEndSeconds(IE151), flowEndMilliseconds(IE153),
   flowEndMicroseconds(IE155) or flowEndNanoseconds(IE157).  While, if
   the computation is done on the node, pathDelayMeanDeltaMicroseconds
   (IE530), pathDelayMinDeltaMicroseconds (IE531),
   pathDelayMaxDeltaMicroseconds (IE532), pathDelaySumDeltaMicroseconds
   (IE533) can be used to export directly the delay information.

3.  IANA Considerations

   This document requests IANA to create new elements under the "IPFIX
   Information Elements" registry [RFC7012] available at [IANA-IPFIX].

   The allocation policy of these new Information Elements is Expert
   Review (Section 4.5 of [RFC8126]).

   The code points are defined in Table 1.

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  +------------+---------------------+-------------------------------------+
  | Element ID |     Name            |              Reference              |
  +------------+---------------------+-------------------------------------+
  | TBD1       | altmarkFlowMonID    | [RFC-to-be],                        |
  |            |                     | RFC9343                             |
  +------------+---------------------+-------------------------------------+
  | TBD2       | altmarkLossFlag     | [RFC-to-be],                        |
  |            |                     | RFC9343                             |
  +------------+---------------------+-------------------------------------+
  | TBD3       | altmarkDelayFlag    | [RFC-to-be],                        |
  |            |                     | RFC9343                             |
  +------------+---------------------+-------------------------------------+
  | TBD4       | altmarkPeriodNumber | [RFC-to-be],                        |
  |            |                     | [I-D.ietf-ippm-alt-mark-deployment] |
  +------------+---------------------+-------------------------------------+

      Table 1: "IPFIX Alternate-Marking" Registry

3.1.  altmarkFlowMonID

   Name: altmarkFlowMonID

   Element ID: TBD1

   Description: The Flow Monitoring Identification (FlowMonID) is
   described in [RFC9343] and identifies the monitored flows with
   AltMark.  It is 20-bit unsigned integer encoded in the 20 least
   significant bits of the 32 bits, while the other bits are set to 0.
   As specified in [RFC9343], it can be set pseudo-randomly by the
   source node or by a centralized controller.  Note that it corresponds
   to the flow-mon-id parameter defined in [I-D.ietf-ippm-alt-mark-yang]
   and [I-D.ietf-ippm-on-path-telemetry-yang].

   Abstract Data Type: unsigned32

   Data Type Semantics: identifier

3.2.  Loss flag

   Name: altmarkLossFlag

   Element ID: TBD2

   Description: Loss flag (L flag) for Packet Loss Measurement as
   described in [RFC9343].  Note that it corresponds to the loss-flag
   parameter defined in [I-D.ietf-ippm-on-path-telemetry-yang].

   Abstract Data Type: boolean

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   Data Type Semantics: default

3.3.  Delay flag

   Name: altmarkDelayFlag

   Element ID: TBD3

   Description: Delay flag (D flag) for Single Packet Delay Measurement
   as described in [RFC9343].  Note that it corresponds to the delay-
   flag parameter defined in [I-D.ietf-ippm-on-path-telemetry-yang].

   Abstract Data Type: boolean

   Data Type Semantics: default

3.4.  Period Number

   Name: altmarkPeriodNumber

   Element ID: TBD4

   Description: The Period Number (PN), described in
   [I-D.ietf-ippm-alt-mark-deployment], is used to help to determine the
   packet counts related to the same block of markers, or the timestamps
   related to the same marked packet.  The PN is associated with each
   packet count and timestamp reported.  It is calculated as the modulo
   of the local time and the interval of the marking time period.  Note
   that it corresponds to the measurement-period-number parameter
   defined in [I-D.ietf-ippm-on-path-telemetry-yang].

   Abstract Data Type: unsigned32

   Data Type Semantics: identifier

4.  Operational Considerations

   The operational and management considerations for the Alternate
   Marking Method are covered in [I-D.ietf-ippm-alt-mark-deployment],
   Alternate Marking [RFC9341] and Multipoint Alternate Marking
   [RFC9342].

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   There are specific considerations to do with regard to the IPFIX
   exporting.  The export interval and the marking period must be
   aligned and the exporting should be done in the middle of the period,
   as described in Alternate Marking [RFC9341].  Also, in case of missed
   exports the corresponding interval is not considered for the
   measurement.  While, if the AltMark period changes, the export
   interval must be modified accordingly.

   Further details about the method operation are specified for the
   different extensions: IPv6 [RFC9343], SRH [RFC9947], and MPLS
   [RFC9714].

5.  Security Considerations

   Alternate Marking [RFC9341] and Multipoint Alternate Marking
   [RFC9342] analyze different security concerns and related solutions.
   These aspects are valid and applicable also to this document.  In
   particular the fundamental security requirement is that Alternate
   Marking MUST only be applied in a specific limited domain, as also
   mentioned in [RFC8799].

   There are no additional security considerations regarding allocation
   of these new IPFIX IEs compared to [RFC7012].  The IEs described in
   this document export AltMark telemetry data.  Applications and
   operators using the IEs described in this document must evaluate the
   sensitivity of this information in their implementation context and
   apply the storage guidance in Section 11.8 of [RFC7011] as
   appropriate.

6.  Acknowledgements

   The authors of this document would like to thank Greg Mirsky, Alex
   Huang Feng, Mohamed Boucadair, Benoit Claise for their comments and
   reviews.

7.  Contributors

   Mauro Cociglio
   Email: mauro.cociglio@outlook.com

   Fabio Bulgarella
   Telecom Italia
   Email: fabio.bulgarella@guest.telecomitalia.it

   Massimo Nilo
   FiberCop

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   Email: massimo.nilo@fibercop.com

   Fabrizio Milan
   FiberCop
   Email: fabrizio.milan@fibercop.com

8.  References

8.1.  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>.

   [RFC7011]  Claise, B., Ed., Trammell, B., Ed., and P. Aitken,
              "Specification of the IP Flow Information Export (IPFIX)
              Protocol for the Exchange of Flow Information", STD 77,
              RFC 7011, DOI 10.17487/RFC7011, September 2013,
              <https://www.rfc-editor.org/info/rfc7011>.

   [RFC7012]  Claise, B., Ed. and B. Trammell, Ed., "Information Model
              for IP Flow Information Export (IPFIX)", RFC 7012,
              DOI 10.17487/RFC7012, September 2013,
              <https://www.rfc-editor.org/info/rfc7012>.

   [RFC7015]  Trammell, B., Wagner, A., and B. Claise, "Flow Aggregation
              for the IP Flow Information Export (IPFIX) Protocol",
              RFC 7015, DOI 10.17487/RFC7015, September 2013,
              <https://www.rfc-editor.org/info/rfc7015>.

   [RFC7133]  Kashima, S., Kobayashi, A., Ed., and P. Aitken,
              "Information Elements for Data Link Layer Traffic
              Measurement", RFC 7133, DOI 10.17487/RFC7133, May 2014,
              <https://www.rfc-editor.org/info/rfc7133>.

   [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>.

   [RFC9341]  Fioccola, G., Ed., Cociglio, M., Mirsky, G., Mizrahi, T.,
              and T. Zhou, "Alternate-Marking Method", RFC 9341,
              DOI 10.17487/RFC9341, December 2022,
              <https://www.rfc-editor.org/info/rfc9341>.

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   [RFC9342]  Fioccola, G., Ed., Cociglio, M., Sapio, A., Sisto, R., and
              T. Zhou, "Clustered Alternate-Marking Method", RFC 9342,
              DOI 10.17487/RFC9342, December 2022,
              <https://www.rfc-editor.org/info/rfc9342>.

   [RFC9343]  Fioccola, G., Zhou, T., Cociglio, M., Qin, F., and R.
              Pang, "IPv6 Application of the Alternate-Marking Method",
              RFC 9343, DOI 10.17487/RFC9343, December 2022,
              <https://www.rfc-editor.org/info/rfc9343>.

   [RFC9714]  Cheng, W., Ed., Min, X., Ed., Zhou, T., Dai, J., and Y.
              Peleg, "Encapsulation for MPLS Performance Measurement
              with the Alternate-Marking Method", RFC 9714,
              DOI 10.17487/RFC9714, February 2025,
              <https://www.rfc-editor.org/info/rfc9714>.

8.2.  Informative References

   [I-D.ietf-ippm-alt-mark-deployment]
              Fioccola, G., Zhu, K., Graf, T., Zhang, L., and M. Nilo,
              "Alternate Marking Deployment Framework", Work in
              Progress, Internet-Draft, draft-ietf-ippm-alt-mark-
              deployment-07, 3 July 2026,
              <https://datatracker.ietf.org/doc/html/draft-ietf-ippm-
              alt-mark-deployment-07>.

   [I-D.ietf-ippm-alt-mark-yang]
              Graf, T., Wang, M., Fioccola, G., Zhou, T., and X. Min, "A
              YANG Data Model for the Alternate Marking Method", Work in
              Progress, Internet-Draft, draft-ietf-ippm-alt-mark-yang-
              05, 11 June 2026, <https://datatracker.ietf.org/doc/html/
              draft-ietf-ippm-alt-mark-yang-05>.

   [I-D.ietf-ippm-on-path-telemetry-yang]
              Fioccola, G., Zhou, T., Zhu, Y., Zhang, W., and K. Zhu,
              "On-Path Telemetry YANG Data Model", Work in Progress,
              Internet-Draft, draft-ietf-ippm-on-path-telemetry-yang-04,
              3 July 2026, <https://datatracker.ietf.org/doc/html/draft-
              ietf-ippm-on-path-telemetry-yang-04>.

   [IANA-IPFIX]
              "IANA, IPFIX",
              <https://www.iana.org/assignments/ipfix/ipfix.xhtml>.

   [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>.

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   [RFC8799]  Carpenter, B. and B. Liu, "Limited Domains and Internet
              Protocols", RFC 8799, DOI 10.17487/RFC8799, July 2020,
              <https://www.rfc-editor.org/info/rfc8799>.

   [RFC9947]  Fioccola, G., Zhou, T., Mishra, G., Wang, X., Zhang, G.,
              and M. Cociglio, "Application of the Alternate-Marking
              Method to the Segment Routing Header", RFC 9947,
              DOI 10.17487/RFC9947, March 2026,
              <https://www.rfc-editor.org/info/rfc9947>.

   [RFC9951]  Graf, T., Claise, B., and A. Huang-Feng, "Export of Delay
              Performance Metrics in IP Flow Information Export
              (IPFIX)", RFC 9951, DOI 10.17487/RFC9951, April 2026,
              <https://www.rfc-editor.org/info/rfc9951>.

Appendix A.  AltMark Examples

   This appendix represents two different examples for the loss and
   delay measurements.

A.1.  Loss Measurement Flow Record

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |          SET ID = 2           |       Length = 40             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |      Template ID = 256        |      Field Count = 8          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| sourceIPv6Address = 27      |      Field Length = 16        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| destinationIPv6Address = 28 |      Field Length = 16        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| altmarkFlowMonID = TBD1     |      Field Length = 4         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| altmarkLossFlag = TBD2      |      Field Length = 1         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| altmarkPeriodNumber = TBD4  |      Field Length = 4         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| packetDeltaCount = 2        |      Field Length = 8         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

         Figure 1: Template Record for Loss Measurements

A.2.  Delay Measurement Flow Record

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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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |          SET ID = 2           |       Length = 40             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |      Template ID = 257        |      Field Count = 8          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| sourceIPv6Address = 27      |      Field Length = 16        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| destinationIPv6Address = 28 |      Field Length = 16        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| altmarkFlowMonID = TBD1     |      Field Length = 4         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| altmarkDelayFlag = TBD3     |      Field Length = 4         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| flowStartMicroseconds = 154 |      Field Length = 8         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

         Figure 2: Template Record for Delay Measurements

Authors' Addresses

   Thomas Graf
   Swisscom
   Binzring 17
   CH-8045 Zurich
   Switzerland
   Email: thomas.graf@swisscom.com

   Giuseppe Fioccola
   Huawei
   Viale Martesana, 12
   20055 Vimodrone (Milan)
   Italy
   Email: giuseppe.fioccola@huawei.com

   Tianran Zhou
   Huawei
   156 Beiqing Rd.
   Beijing
   100095
   China
   Email: zhoutianran@huawei.com

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   Yongqing Zhu
   China Telecom
   China
   Email: zhuyq8@chinatelecom.cn

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