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Integrating the Alternate-Marking Method into In Situ Operations, Administration, and Maintenance (IOAM)
draft-he-ippm-integrating-am-into-ioam-02

Document Type Active Internet-Draft (individual)
Authors hexiaoming , Frank Brockners , Haoyu Song , Giuseppe Fioccola , Aijun Wang
Last updated 2024-06-20
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draft-he-ippm-integrating-am-into-ioam-02
IPPM Working Group                                                 X. He
Internet-Draft                                             China Telecom
Intended status: Standards Track                            F. Brockners
Expires: 22 December 2024                                          Cisco
                                                                 H. Song
                                                               Futurewei
                                                             G. Fioccola
                                                                  Huawei
                                                                 A. Wang
                                                           China Telecom
                                                            20 June 2024

   Integrating the Alternate-Marking Method into In Situ Operations,
                 Administration, and Maintenance (IOAM)
               draft-he-ippm-integrating-am-into-ioam-02

Abstract

   In situ Operations, Administration, and Maintenance (IOAM) is used
   for recording and collecting operational and telemetry information.
   Specifically, passport-based IOAM allows telemetry data generated by
   each node along the path to be pushed into data packets when they
   traverse the network, while postcard-based IOAM allows IOAM data
   generated by each node to be directly exported without being pushed
   into in-flight data packets.  This document extends IOAM Direct
   Export (DEX) Option-Type to integrate the Alternate-Marking Method
   into IOAM.

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 22 December 2024.

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Copyright Notice

   Copyright (c) 2024 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include 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
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  Problems and Challenges . . . . . . . . . . . . . . . . . . .   3
   4.  Integrate the Alternate-Marking Method into IOAM  . . . . . .   4
   5.  The Extended DEX Option-Type Format . . . . . . . . . . . . .   5
   6.  The IOAM Operation  . . . . . . . . . . . . . . . . . . . . .   7
     6.1.  Packet Loss Measurement . . . . . . . . . . . . . . . . .   8
     6.2.  Packet Delay Measurement  . . . . . . . . . . . . . . . .   8
     6.3.  Flow Identification . . . . . . . . . . . . . . . . . . .   9
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
     7.1.  IOAM Type . . . . . . . . . . . . . . . . . . . . . . . .  10
     7.2.  IOAM DEX Extension-Flags  . . . . . . . . . . . . . . . .  11
   8.  Performance Considerations  . . . . . . . . . . . . . . . . .  11
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  12
     10.2.  Informative References . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   IOAM [RFC9197], which defines four possible IOAM-Option-Types: Pre-
   allocated Trace, Incremental Trace, Proof of Transit (POT), and Edge-
   to-Edge, is used for monitoring traffic in the network and for
   incorporating IOAM data fields into in-flight data packets.  IOAM
   [RFC9197] is known as the passport mode, in which each node on the
   path can add telemetry data to the user packets (i.e., stamps the
   passport).  IOAM Direct Export (DEX) [RFC9326] is used as a trigger
   for IOAM nodes to directly export IOAM data to a receiving entity
   such as a collector, analyzer, or controller.  IOAM DEX is also
   referred as the postcard mode, in which each node directly exports
   the telemetry data using an independent packet (i.e., sends a

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   postcard) while the user packets are unmodified.

   The disadvantage of the passport mode is that if a packet is dropped
   on the path, the IOAM data collected are also lost.  So the passport
   mode such as IOAM Trace Option-Type has no ability to monitor packet
   drop and packet drop location.

   IOAM DEX Option-Type can complement IOAM Trace Option-Type in that
   even if a packet is dropped on the path, the partial data collected
   are still available.  By correlating the data from different nodes,
   the number of the discarded packets can be counted accurately and
   packet drop location can be pinpointed.

   The Alternate-Marking [RFC9341] technique has been proven to work
   well to perform packet loss, delay, and jitter measurements on live
   traffic.  RFC9343 describes how the Alternate-Marking Method can be
   used to measure performance metrics in IPv6.  It defines an Extension
   Header Option to encode Alternate-Marking information in both the
   Hop-by-Hop Options Header and Destination Options Header.  In order
   to facilitate the deployment and improve the scalability of the
   Alternate-Marking Method, the Flow Monitoring Identification
   (FlowMonID) field is introduced.  The benefits of introducing
   FlowMonID are obvious: First, it helps to reduce the per-node
   configuration; Second, it simplifies the counters handling; Third, it
   eases the data export encapsulation and correlation for the
   collectors.

   This document presents the problems and challenges currently faced by
   IOAM in measuring performance metrics such as packet loss, delay, and
   jitter.  In order to augment performance measurement of IOAM, IOAM
   DEX Option-Type is extended to incorporate the Alternate-Marking
   Method into IOAM.

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.  Problems and Challenges

   Although IOAM DEX Option-Type can complement IOAM Trace Option-Type
   for monitoring packet loss, some issues have to be considered as
   follows.

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   Issue 1: If an IOAM encapsulating node incorporates the DEX Option-
   Type into all the traffic of interest it forwards, it may lead to an
   excessive amount of exported data, which may overload the network and
   the receiving entity.  Therefore, an IOAM encapsulating node that
   supports the DEX Option-Type MUST support the ability to incorporate
   the DEX Option-Type selectively into a subset of the packets that are
   forwarded by the IOAM encapsulating node.

   Issue 2: In theory, if an IOAM encapsulating node incorporates the
   DEX Option-Type into all the traffic it forwards, the fidelity of
   packet loss measurement can be ensured.  If the too small subset of
   traffic or too low traffic sampling on an encapsulating node is
   implemented, loss measurement results can not reflect the actual
   packet drop, due to the fact that the transmitting packet interval
   does not cover packet drop caused by instantaneous congestion such as
   microbursts.

   Issue 3: Because the IOAM data of the same user packet is generated
   by every node along the path, the receiving entity needs more
   processing overhead to correlate these data for packet loss
   computation.  The more user packets measured, the more processing
   overhead is required.

   Issue 4: While using the Alternate-Marking Method, traffic flows are
   split into consecutive blocks: each block represents a measurable
   entity unambiguously recognizable by all network devices along the
   path.  In contrast, based on IOAM DEX Option-Type, every IOAM node
   directly exports an IOAM data to a receiving entity when every user
   packet is forwarded, and the collected IOAM data are not split into
   independent measurement blocks.  It is the receiving entity's
   responsibility to determine the measurement period for performance
   metrics such as packet loss, delay, and jitter, which is not
   beneficial to a unified measurement methodology.

4.  Integrate the Alternate-Marking Method into IOAM

   To address the issues and challenges mentioned in Section 3, IOAM
   needs to be augmented to implement performance measurement.  The
   Alternate-Marking Method has been widely employed in operators
   networks.  By integrating the Alternate-Marking Method into IOAM, the
   benefits obtained include:

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   *  While implementing performance measurement, an IOAM encapsulating
      node may incorporate the DEX Option-Type into all the traffic of
      interest it forwards; Meanwhile, an IOAM encapsulating node only
      needs to select a very small subset of the packets that are
      forwarded for IOAM trace monitoring (e.g., 1/10000 of all the
      traffic of interest), so the amount of exported data is
      significantly reduced to mitigate the network and the receiving
      entity.  The IOAM operation is detailed in section 6.

   *  Using the Alternate-Marking Method, an IOAM encapsulating node
      could color all the traffic of interest it forwards, not a subset
      of the packets, thus the fidelity of performance measurement such
      as packet loss can be ensured.

   *  While using the Alternate-Marking Method, and in Hop-by-Hop mode
      for loss measurement, every node along the path only exports a
      packet carrying counter value of each measurement block including
      a batch of packets; In End-to-End mode for loss measurement, only
      the IOAM encapsulating node and the IOAM decapsulating node export
      a packet carrying counter value of each measurement block.  It
      mitigates the network and the receiving entity greatly.
      Furthermore, compared to IOAM DEX Option-Type, the receiving
      entity requires much less processing overhead to correlate these
      counter values for packet loss computation.

   *  While using the Alternate-Marking Method, traffic flows are split
      into consecutive blocks: each block represents a measurable entity
      unambiguously recognizable by all network devices along the path,
      thus the measurement period is completely determined by network
      devices.  The receiving entity does not need to concern about
      determination of measurement period, but only compute the result
      of each measurement period.  It is beneficial to a unified
      measurement methodology.

   *  Furthermore, by incorporating the Alternate-Marking Method into
      IOAM, only unique packet header encapsulation format is used for
      both IOAM trace monitoring and performance measurement such packet
      loss, latency and jitter, thus simplifing the complexity of
      forwarding chips.

5.  The Extended DEX Option-Type Format

   The format of the extended DEX Option-Type is depicted in Figure 1.
   All fields are same as DEX Option-Type Format defined in RFC9326
   except the Reserved field.  The extended DEX Option-Type Format uses
   the most significant 2 bits of the Reserved field.

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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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |        Namespace-ID           |     Flags     |Extension-Flags|
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |               IOAM-Trace-Type                 |D|L| Reserved  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                         Flow ID (Optional)                    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                     Sequence Number  (Optional)               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |             Measurement Period Number  (Optional)             |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 1: The Extended DEX Option-Type Format

   Where:

   Namespace-ID: 16-bit identifier of the IOAM namespace, as defined in
   [RFC9197].

   Flags: 8-bit field, comprised of 8 1-bit subfields.  Flags are
   allocated by IANA.

   Extension-Flags: 8-bit field, comprised of 8 1-bit subfields.
   Extension-Flags are allocated by IANA.  Every bit in the Extension-
   Flag field that is set to 1 indicates the existence of a
   corresponding optional 4-octet field.  Bit 0 (the most significant
   bit) and bit 1 in the registry are allocated by [RFC9326], which are
   specified as Flow ID and Sequence Number of the monitored traffic,
   respectively.  Bit 2 is specified as Measurement Period Number in
   this document.  An IOAM node that receives an extended DEX Option-
   Type with an unknown flag set to 1 MUST ignore the corresponding
   optional field.

   IOAM-Trace-Type: 24-bit identifier that specifies which IOAM data
   types are used and the corresponding IOAM-Data-Fields should be
   exported.  The format of this field is as defined in [RFC9197].

   L: 1-bit Loss flag for Packet Loss Measurement as described in
   Section 6.1.

   D: 1-bit Delay flag for Single Packet Delay Measurement as described
   in Section 6.2.

   Reserved: 6-bit field, reserved for future use.  These bits MUST be
   set to zero on transmission and ignored on receipt.

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   Optional fields: The optional fields, if present, reside after the
   Reserved field.  The order of the optional fields is according to the
   order of the respective bits, starting from the most significant bit,
   that are enabled in the Extension-Flags field.  Each optional field
   is 4 octets long.

   Flow ID: An optional 32-bit field representing the flow identifier.
   If the actual Flow ID is shorter than 32 bits, it is zero padded in
   its most significant bits.  The field is set at the encapsulating
   node and exported to the receiving entity by the forwarding nodes.
   The Flow ID can be used to correlate the exported data of the same
   flow from multiple nodes and from multiple packets.  Flow ID values
   are expected to be allocated in a way that avoids collisions.  For
   example, random assignment of Flow ID values can be subject to
   collisions, while centralized allocation can avoid this problem.  The
   specification of the Flow ID allocation method is not within the
   scope of this document.

   Sequence Number: An optional 32-bit sequence number, starting from 0
   and incremented by 1 for each packet from the same flow at the
   encapsulating node that includes the DEX option.  The Sequence
   Number, when combined with the Flow ID, provides a convenient
   approach to correlate the exported data from the same user packet.

   Measurement Period Number(MPN): An optional 32-bit field representing
   the measurement period number of the monitored flow, starting from 0
   and incremented by 1 for the specified flow with the same Flow ID.
   The field is set at the encapsulating node and exported to the
   receiving entity by the forwarding nodes.  The MPN, when combined
   with the Flow ID, provides a convenient approach to correlate the
   exported data of the same flow during the same measurement period
   from multiple nodes.

6.  The IOAM Operation

   The extended DEX Option-Type SHOULD support to perform both
   performance measurement and IOAM trace monitoring concurrently.
   While both performance measurement and IOAM trace monitoring are
   implemented concurrently, an IOAM encapsulating node MUST incorporate
   the extended DEX Option-Type into all the traffic of interest it
   forwards.  For performance measurement, an IOAM encapsulating node
   MUST mark every packet it forwards in "L" and "D" flag of the
   extended DEX Option-Type; for IOAM trace monitoring, only a subset of
   the packets are selected by an IOAM encapsulating node.  For every
   selected packet, an IOAM encapsulating node MUST set corresponding
   bit flag to 1 in IOAM Trace-Type field of the extended DEX Option-
   Type so that each node along the path needs to generate the specified
   IOAM data exported to the receiving entity; for all the other packets

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   not selected, an IOAM encapsulating node MUST set all 24 bits flag to
   0 in IOAM Trace-Type field of the extended DEX Option-Type, such that
   each node along the path does not need to generate the IOAM data
   exported to the receiving entity.

6.1.  Packet Loss Measurement

   The measurement of the packet loss is detailed in [RFC9341]and
   [RFC9343].  The packets of the flow identified by Flow ID are grouped
   into batches, and all the packets within a batch are marked by
   setting the L bit (Loss flag) to a same value.  The source node (IOAM
   encapsulating node) can switch the value of the L bit between 0 and 1
   after a fixed number of packets or according to a fixed timer, and
   this depends on the implementation.  The source node is the only one
   that marks the packets to create the batches, while the intermediate
   nodes only read the marking values and identify the packet batches.
   By counting the number of packets in each batch and comparing the
   values measured by different network nodes along the path, it is
   possible to measure the packet loss that occurred in any single batch
   between any two nodes.  Each batch represents a measurable entity
   recognizable by all network nodes along the path, which export the
   counter value of this batch along with the Flow ID and the MPN (if it
   exists) to the receiving entity (e.g., the collector).

6.2.  Packet Delay Measurement

   Delay metrics MAY be calculated using the following two
   possibilities:

   Single-Marking Methodology: This approach uses only the L bit to
   calculate both packet loss and delay.  In this case, the D flag MUST
   be set to zero on transmit and ignored by the monitoring points.  The
   alternation of the values of the L bit can be used as a time
   reference to calculate the delay.  Whenever the L bit changes and a
   new batch starts, a network node can store the timestamp of the first
   packet of the new batch; that timestamp can be compared with the
   timestamp of the first packet of the same batch on a second node to
   compute packet delay.  But, this measurement is accurate only if no
   packet loss occurs and if there is no packet reordering at the edges
   of the batches.  A different approach can also be considered, and it
   is based on the concept of the mean delay.  The mean delay for each
   batch is calculated by considering the average arrival time of the
   packets for the related batch.  There are limitations also in this
   case indeed; each node needs to collect all the timestamps and
   calculate the average timestamp for each batch.  In addition, the
   information is limited to a mean value.

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   Double-Marking Methodology: This approach is more complete and uses
   the L bit only to calculate packet loss, and the D bit (Delay flag)
   is fully dedicated to delay measurements.  The idea is to use the
   first marking with the L bit to create the alternate flow and, within
   the batches identified by the L bit, a second marking with the D bit
   set to 1 is used to select the packets for measuring delay.  The D
   bit creates a new set of marked packets that are fully identified
   over the network so that a forwarding node can store and export the
   timestamps of these packets; these timestamps can be compared with
   the timestamps of the same packets on a second node to compute packet
   delay values for each packet.  Sequence Number can be used to
   identify multiple timestamps in different packets that pertain to the
   same measurement block in case of packets out of order.  The most
   efficient and robust mode is to select a single double-marked packet
   for each batch; in this way, there is no time gap to consider between
   the double-marked packets to avoid their reorder.  If a double-marked
   packet is lost, the delay measurement for the considered batch is
   simply discarded, but this is not a big problem because it is easy to
   recognize the problematic batch and skip the measurement just for
   that one.  So in order to have more information about the delay and
   to overcome out-of-order issues, this method is preferred.

   In summary, the approach with Double Marking is better than the
   approach with Single Marking.  In the implementation, the timestamps
   along with Flow ID and Sequence Number (if it exists) can be sent out
   to the receiving entity that is responsible for the calculation.

6.3.  Flow Identification

   The Flow Identification (Flow ID) identifies the flow to be measured
   and is required for some general reasons, which is described in
   Section 5.3 of [RFC9343].  [RFC9343] uses 20-bit FlowMonID to
   determine a monitored flow within the measurement domain.  Compared
   to the FlowMonID, the Flow ID in this document is a 32-bit field,
   which amplifies the FlowMonID space by 4096 times.  Accordingly, a
   chance of collision is greatly reduced in a distributed way.

   When the 32-bit Flow ID is used for every source node, if there are N
   edge nodes (source nodes) in a large-scale operator network, and each
   source node can generate a unique Flow ID for every measured flow
   independently and randomly in a distributed way.  Assuming that each
   node randomly generates M different Flow IDs from the available K
   flow identification space, then the total possible sample space is

   the Nth power of C (K, M)

   and the total possible sample space not duplicate is

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   C1 (K, M)*C2 (K-M, M )*....*CN (k-(N-1)M, M)

   Theoritically, the non collision probability is calculated as the
   total possible sample space not duplicate divided by the total
   possible sample space.

   Take K=32nd power of 2, N=100, M=100 as an example, and the non
   collision probability is 0.9885.  That is to say, when generating
   10000 concurrent flows, there might be 115 measured flow identifiers
   incurring a chance of collision.  If K=20th power of 2 is taken,
   which corresponds to 20-bit Flow ID space, the collision probability
   will drastically increases to approximately 100%. In practical
   deployment scenarios of large-scale networks, the simultaneous
   measurement flows could reach orders of magnitude of 100000 or even
   higher, thus the collision probability will rise sharply.

   It is preferred that Flow ID be assigned by the central controller.
   Since the controller knows the network topology, it can allocate the
   value properly to guarantee the uniqueness of Flow ID allocation.

   In some cases where the central controller is not available and the
   distributed way must be adopted, every source node (encapsulating
   node) needs to allocate Flow ID independently.  In order to avoid the
   collision, Flow ID field may be devided into two sub-fields: NodeID
   and FlowMonID.  NodeID is assigned uniquely in measurement domain and
   FlowMonID is assigned randomly and uniquely in a device.  The length
   allocation of the two sub-fields depends on practical implementation,
   for example, NodeID uses 20 bits and FlowMonID uses 16 bits, or both
   use an average of 16 bits.

7.  IANA Considerations

7.1.  IOAM Type

   The "IOAM Option-Type" registry is defined in Section 7.1 of
   [RFC9197].

   IANA is requested to allocate the following code point from the "IOAM
   Option-Type" registry as follows:

            +=======+===============================+===============+
            | Value | Description                   | Reference     |
            +=======+===============================+===============+
            |  TBA  | IOAM Extended DEX Option Type | This document |
            +-------+-------------------------------+---------------+

   If possible, IANA is requested to allocate code point 5 (TBA-type).

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7.2.  IOAM DEX Extension-Flags

   IANA has created the "IOAM DEX Extension-Flags" registry.  This
   registry includes 8 flag bits.  Bit 0 (the most significant bit) and
   bit 1 in the registry are allocated by [RFC9326].

   IANA is requested to allocate bit 2 as Measurement Period Number in
   the registry and described in Section 5.

8.  Performance Considerations

   The extended DEX Option-Type triggers IOAM data (including IOAM trace
   data and performance measurement data) to be collected and/or
   exported packets to be exported to a receiving entity.  In some
   cases, this may impact the receiving entity's performance.

   Therefore, the performance impact of these exported packets is
   limited by taking two measures: at the encapsulating nodes by
   selective DEX encapsulation and at the transit nodes by limiting
   exporting rate, which are detailed in [RFC9326].  These two measures
   ensure that direct exporting is used at a rate that does not
   significantly affect the network bandwidth and does not overload the
   receiving entity.

   When performance measurement is implemented based on the Alternate-
   Marking Method, and in Hop-by-Hop mode for loss measurement, every
   node along the path only exports a packet carrying counter value of
   each measurement block including a batch of packets; In End-to-End
   mode for loss measurement, only the IOAM encapsulating node and the
   IOAM decapsulating node export a packet carrying counter value of
   each measurement block.  Meanwhile, an IOAM encapsulating node only
   needs to select a very small subset of the packets that are forwarded
   for IOAM trace monitoring (e.g., 1/10000 of all the traffic), so the
   amount of exported data is significantly reduced to mitigate the
   network and the receiving entity.  In addition, compared with IOAM
   DEX Option-Type for packet loss calculation, due to a significant
   reduction in the number of exported packets, the receiving entity
   needs much less processing overhead to correlate these counter values
   for packet loss computation.

9.  Security Considerations

   The security considerations of IOAM in general are discussed in
   [RFC9197], and the security considerations of IOAM DEX Option-Type
   are discussed in [RFC9326].  There are not additional security
   considerations in this extended IOAM DEX Option-Type.

10.  References

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10.1.  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>.

   [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>.

   [RFC9197]  Brockners, F., Ed., Bhandari, S., Ed., and T. Mizrahi,
              Ed., "Data Fields for In Situ Operations, Administration,
              and Maintenance (IOAM)", RFC 9197, DOI 10.17487/RFC9197,
              May 2022, <https://www.rfc-editor.org/info/rfc9197>.

   [RFC9326]  Song, H., Gafni, B., Brockners, F., Bhandari, S., and T.
              Mizrahi, "In Situ Operations, Administration, and
              Maintenance (IOAM) Direct Exporting", RFC 9326,
              DOI 10.17487/RFC9326, November 2022,
              <https://www.rfc-editor.org/info/rfc9326>.

   [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>.

   [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>.

10.2.  Informative References

   [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>.

   [RFC9486]  Bhandari, S., Ed. and F. Brockners, Ed., "IPv6 Options for
              In Situ Operations, Administration, and Maintenance
              (IOAM)", RFC 9486, DOI 10.17487/RFC9486, September 2023,
              <https://www.rfc-editor.org/info/rfc9486>.

Authors' Addresses

   Xiaoming He
   China Telecom

He, et al.              Expires 22 December 2024               [Page 12]
Internet-Draft  Integrating the Alternate-Marking Method       June 2024

   Email: hexm4@chinatelecom.cn

   Frank Brockners
   Cisco
   Email: fbrockne@cisco.com

   Haoyu Song
   Futurewei
   Email: haoyu.song@futurewei.com

   Giuseppe Fioccola
   Huawei
   Email: giuseppe.fioccola@huawei.com

   Aijun Wang
   China Telecom
   Email: wangaj3@chinatelecom.cn

He, et al.              Expires 22 December 2024               [Page 13]