CORE Working Group                                           G. Fioccola
Internet-Draft                                                   T. Zhou
Intended status: Standards Track                                  Huawei
Expires: 27 April 2023                                       M. Cociglio
                                                           F. Bulgarella
                                                                 M. Nilo
                                                          Telecom Italia
                                                         24 October 2022


 Constrained Application Protocol (CoAP) Performance Measurement Option
                        draft-fz-core-coap-pm-03

Abstract

   This document specifies a method for the Performance Measurement of
   the Constrained Application Protocol (CoAP).  A new CoAP option is
   defined in order to enable network telemetry both end-to-end and on-
   path.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

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 27 April 2023.

Copyright Notice

   Copyright (c) 2022 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
   2.  Performance Measurement methods for CoAP  . . . . . . . . . .   3
     2.1.  sQuare bit and Spin bit . . . . . . . . . . . . . . . . .   4
     2.2.  Combined sQuare bit . . . . . . . . . . . . . . . . . . .   4
   3.  CoAP Performance Measurement Option . . . . . . . . . . . . .   5
   4.  Structure of the PM Option  . . . . . . . . . . . . . . . . .   6
   5.  Application Scenarios . . . . . . . . . . . . . . . . . . . .   8
     5.1.  Non-proxying endpoints  . . . . . . . . . . . . . . . . .   8
     5.2.  Collaborating or Non-collaborating proxies  . . . . . . .   9
     5.3.  OSCORE  . . . . . . . . . . . . . . . . . . . . . . . . .  11
   6.  Management and Configuration  . . . . . . . . . . . . . . . .  12
   7.  Congestion Control  . . . . . . . . . . . . . . . . . . . . .  12
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  13
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  13
     11.2.  Informative References . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   [RFC7252] define the CoAP Protocol.  In CoAP, reliability is provided
   by marking a message as Confirmable (CON) with ACKs.  A message that
   does not require reliable transmission can be sent as a Non-
   confirmable message (NON).

   In case of CoAP reliable mode there are Message IDs and ACKs, that
   could eventually be used to measure Round-Trip Time (RTT) and losses.
   But it can be resource-consuming for constrained nodes since they
   have to look at Message IDs and take timestamps.  These operations
   are expensive in terms of resources.  In case of CoAP unreliable
   mode, there is no ACK and, consequently, it is not possible to
   measure RTT and losses.






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   Thus, there is no easy way to measure the performance metrics in COAP
   environment to satisfy the low resources of constrained nodes.  And
   it is in any case limited to RTT and end-to-end losses.

   A mechanism to measure the performance in CoAP can be useful to
   verify and meet the operational requirements, but it should be a
   simple mechanism for network diagnostic to be developed on
   constrained nodes requiring just a minimal amount of collaboration
   from the endpoints.

   [I-D.ietf-ippm-explicit-flow-measurements] describes the
   methodologies for Explicit Flow Measurement (EFM).  The EFM
   techniques employ few marking bits, inside the header of each packet,
   for loss and delay measurement.  These are relevant for encrypted
   protocols, e.g.  QUIC [RFC9000], where there are only few bits
   available in the non-encrypted header in order to allow passive
   performance metrics from an on-path observer.  These methodologies
   could potentially be used and extended in CoAP.

   [I-D.ietf-ippm-explicit-flow-measurements] defines different
   combinations of bits because the number of bits in QUIC is limited
   and different experiments have been done.  But all these methods
   together imply complex algorithms that do not apply well to the CoAP
   environment.

   This document aims to create an easy way to allow performance
   measurement for CoAP, by defining a new option, called Performance
   Measurement (PM) CoAP Option.  The CoAP performance metrics (e.g.
   RTT and losses) can be useful for an operator or an enterprise that
   is managing a constrained, low-power and lossy network.

2.  Performance Measurement methods for CoAP

   CoAP [RFC7252] defines a number of options that can be included in a
   message.  For this reason, a new option for CoAP, carrying
   Performance Measurement (PM) bits is the approach followed by this
   document.

   The PM bits that are included in the Option are:

   *  sQuare bit (Q bit), based on [I-D.ietf-ippm-rfc8321bis] and
      further described in [I-D.ietf-ippm-explicit-flow-measurements];

   *  Spin bit (S bit), described in [RFC9312] and included as optional
      bit in [RFC9000];

   *  Loss and Delay event information for further usage.




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   A requirement to enable PM methods in COAP environment is that the
   methodologies and the algorithm needs to be kept simple.  For this
   reason, the idea is to re-apply only the S bit and Q bit.

   Thus, the advantages of using the CoAP PM Option are:

      1) Simplification because it is not needed to read Message IDs,
      indeed there is a well-defined sQuare wave, and it is not
      necessary to store timestamps, since the duration of the Spin Bit
      period is equal to RTT.

      2) Enabling easy on-path observer (proxy, gateway) metrics.

2.1.  sQuare bit and Spin bit

   The sQuare bit algorithm consists of creating square waves of a known
   length (e.g. 64 packets).  Each side of the connection can set the Q
   bit and toggle its value every fixed number of packets.  The number
   of packets can be easily recognized and packet loss can be measured.

   The Spin bit algorithm consists of creating a square wave signal on
   the data flow, using a bit, whose length is equal to RTT.  The Spin
   bit causes one bit to 'spin', generating one edge (a transition from
   0 to 1 or from 1 to 0) once per end-to-end RTT.  The Spin bit is set
   by both sides to the same value for as long as one round trip lasts
   and then it toggles the value.

   All the possible measurements (end-to-end, hop-by-hop) that are
   enabled by Q bit and S bit are detailed in
   [I-D.ietf-ippm-explicit-flow-measurements].

2.2.  Combined sQuare bit

   The synergy between S bit and Q bit is also possible.  As described
   above, the length of the Q bit square waves is fixed (e.g. a
   predefined number of packets) in this way each endpoint can detect a
   packet loss if it receives less packets than expected.  It is
   possible to potentiate the Q bit signal by incorporating RTT
   information as well.  This implies a little modification to the
   algorithm of the Q bit that could also be used alone:











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      A single packet in a period of the square wave can be selected and
      set to the opposite value of that period.  After one RTT it comes
      back and another packet is selected and set again to the opposite
      value of that period.  And the process can start again.  By
      measuring the distance between these special packets, it is
      possible to measure the RTT in addition to packet loss.  The
      periods with the special packets have one packet less than
      expected but this is easy to recognize and to take into account by
      both endpoints.

   This mechanism uses a single bit that serves two purposes: a loss
   indicator and a delay indicator.  It is worth highlighting that the
   mechanism is similar to the Delay bit (D bit), described in
   [I-D.ietf-ippm-explicit-flow-measurements].  Indeed, the Delay bit is
   set only once per RTT and a single packet with the marked Delay bit
   bounces between a client and a server.

   The Q bit and D bit signals use two single bit values and the new
   signal is a Combined sQuare bit (C bit) signal.  The C bit value is
   given by an Exclusive OR operation (XOR) between the two Q bit and D
   bit values: C = Q XOR D.

   Since C bit incorporates both Q bit and D bit information, the same
   considerations for the two separate signals in
   [I-D.ietf-ippm-explicit-flow-measurements] can also be extended in
   the case of C bit.  Therefore, all the possible measurements (end-to-
   end, hop-by-hop) that are enabled by using only C bit can be found in
   [I-D.ietf-ippm-explicit-flow-measurements] by merging Q bit and D bit
   derived measurements.

3.  CoAP Performance Measurement Option

   Figure 1 shows the property of the CoAP Performance Measurement (PM)
   Option.  The formatting of this table is reported in [RFC7252].  The
   C, U, N, and R columns indicate the properties Critical, Unsafe,
   NoCacheKey, and Repeatable as defined in [RFC7252].  None of these
   properties is marked for the PM options.

      +--------+---+---+---+---+--------+--------+--------+---------+
      | Number | C | U | N | R | Name   | Format | Length | Default |
      +========+===+===+===+===+========+========+========+=========+
      | TBD    |   |   | x |   |   PM   | uint   | 1      | 0       |
      +--------+---+---+---+---+--------+--------+--------+---------+

                    Figure 1: CoAP PM Option Properties

   The CoAP PM Option is Elective, Safe-to-Forward and it is not to be
   included in the Cache-Key (NoCacheKey is set).



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   Note that it could be possible to make use of one bit in the option
   to identify the mode.  In this way two patterns can be defined.

4.  Structure of the PM Option

   The value of the PM option is a 1 byte unsigned integer.  This
   integer value encodes the following fields:

                           0
                           0 1 2 3 4 5 6 7
                          +-+-+-+-+-+-+-+-+
                          |M|   Pattern   |
                          +-+-+-+-+-+-+-+-+

               Figure 2: CoAP Performance Measurement Option

   Where:

   *  The Mode bit (M bit) can be set to 1 or 0 and it is used to
      identify whether the Option follows pattern 1 (M bit = 0) or
      pattern 2 (M bit = 1).

   *  Pattern bits can be of two kinds as reported below.

   The PM Option can employ two patterns based on the value of the M
   bit:

                           0
                           0 1 2 3 4 5 6 7
                          +-+-+-+-+-+-+-+-+
                          |0|C|   Event   |
                          +-+-+-+-+-+-+-+-+

          Figure 3: CoAP Performance Measurement Option pattern 1

                           0
                           0 1 2 3 4 5 6 7
                          +-+-+-+-+-+-+-+-+
                          |1|Q|S|  Event  |
                          +-+-+-+-+-+-+-+-+

          Figure 4: CoAP Performance Measurement Option pattern 2

   The COAP Option could be defined with 2 PM bits (S and Q) or defined
   with a single PM bit (C bit).

   Where:




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   *  C bit is used in pattern 1.  It is based on the enhancement of the
      Q bit signal with the S bit information.  The two methods are
      described in [I-D.ietf-ippm-explicit-flow-measurements] and
      coupled as detailed in Section 2.2;

   *  Q bit is used in pattern 2.  It is described in
      [I-D.ietf-ippm-explicit-flow-measurements];

   *  S bit is used in pattern 2.  It is desribed in [RFC9312] and also
      embedded in the QUIC Protocol [RFC9000];

   *  Event bits MAY encode additional Loss and Delay information based
      on well-defined encoding and they can also be used by on-path
      observers.  If these Event bits are all zero, they MUST be ignored
      on receipt.

   It is worth noting that the only differences between the two patterns
   are related to the accuracy of the measurements.  Further details can
   be found in [I-D.ietf-ippm-explicit-flow-measurements].

   The Event bits can be divided into two parts, for instance: loss
   event bits and delay event bits.  Based on the average RTT, an end
   point can define different levels of thresholds and set the delay
   event bits accordingly.  The same applies to loss event bits.  In
   this way an on-path observer becomes aware of the network conditions
   by simply reading these Event bits.

   The on-path observer can read the event signaling bits and could be
   the Proxy or the Gateway which interconnects disjointed CoAP
   networks.  It MAY communicate with Client and Server to set some
   parameters such as timeout based on the network performance.

   The CoAP PM Options described in this document can be used in both
   requests and responses.  If a CoAP endpoint does not implement the
   measurement methodologies, it can simply leave the default value (all
   bits are zero).  In this way the other CoAP endpoints become aware
   that the measurement cannot be executed in that case.

   The fixed number of packets to create the Q bit (or C bit) signal is
   predefined and its value is configured from the beginning for all the
   CoAP endpoints.










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5.  Application Scenarios

   The main usage of the CoAP PM Options is to do end-to-end measurement
   between the client and the server but it can also allow split
   measurements.  The on-path measurement is the additional feature.
   This information can be used to monitor the network in order to check
   the operational performance and to employ further network
   optimization.

   The intermediaries or on-path observers could be:

      Network Functions or Probes that must be able to see deep into
      application.

      Gateway or Proxies that, as specified in [RFC7252], are CoAP
      endpoints tasked by CoAP clients to perform requests on their
      behalf.

5.1.  Non-proxying endpoints

   The CoAP PM Option can be applied end-to-end between client and
   server and, since it is Elective, it can be ignored by an endpoint
   that does not understand it.

        +--------+                               +--------+
        | Client |---------------+---------------| Server |
        +--------+               |               +--------+
                                 |
                              observer

               Figure 5: Scenario with non-proxying endpoints

   The enabled measurements are:

   *  end-to-end loss and delay measurements between Client and Server,

   *  on-path upstream and downstream loss and delay components (as
      explained in [I-D.ietf-ippm-explicit-flow-measurements]) if there
      is an observer (e.g. network functions or probes).

   *  on-path intra-domain loss and delay portion as a result of the
      difference between the computed upstream or downstream components
      (as explained in [I-D.ietf-ippm-explicit-flow-measurements]).








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   The on-path network probes can read Q bit and S bit (or C bit) and
   implement the relevant algorithms to measure losses and RTT.
   Otherwise they can simply read the Event bits and be informed about
   the performance without implementing any algorithm.  The event
   signaling bits can be sent from the Server (that can do the
   performance measurement calculation) to the Client, or viceversa.

   if the CoAP PM Option is applied between client and the server, an
   Observer can measure the total RTT by using the S bit, indeed it
   allows RTT measurement for all the intermediate points.
   Additionally, with the Q bit and by applying
   [I-D.ietf-ippm-rfc8321bis], it is also possible to do hop-by-hop
   measurements for loss and delay and segment where possible, according
   to the methodologies described in
   [I-D.ietf-ippm-explicit-flow-measurements].  Alternatively, it is
   possible to use the C bit to get the same information for loss and
   delay as explained in [I-D.ietf-ippm-explicit-flow-measurements].

5.2.  Collaborating or Non-collaborating proxies

   The CoAP PM Option can be applied end-to-end between client and
   server (or between Proxies), and since it is Safe-to-Forward, it is
   intended to be safe for forwarding by a proxy that does not
   understand it.

     +--------+       +-----+                 +-----+       +--------+
     | Client |---+---|Proxy|--------+--------|Proxy|---+---| Server |
     +--------+   |   +-----+        |        +-----+   |   +--------+
                  |                  |                  |
               observer           observer           observer

                      Figure 6: Scenario with proxies

   The proxies can be collaborating and it means that they understand
   and are configured to handle the CoAP PM Option.  Otherwise, the
   proxies can be non-collaborating and this means that they do not
   handle the CoAP PM Option.

   In case of collaborating proxies, the enabled measurements are
   different depending on where it is applied the CoAP PM Option:

   *  It can be possible to apply the CoAP PM Option between Client and
      Server and the enabled measurements can be:

      -  end-to-end loss and delay measurements between Client and
         Server,





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      -  on-path upstream and downstream loss and delay components (as
         explained in [I-D.ietf-ippm-explicit-flow-measurements]) on
         each Proxy,

      -  on-path upstream and downstream loss and delay components (as
         explained in [I-D.ietf-ippm-explicit-flow-measurements]) on
         each Observer,

      -  on-path intra-domain loss and delay portion as a result of the
         difference between the computed upstream or downstream
         components (as explained in
         [I-D.ietf-ippm-explicit-flow-measurements]).

   *  It can also be possible to apply the CoAP PM Option between the
      collaborating Proxies (instead of Client and Server) and the
      enabled measurements can be:

      -  end-to-end loss and delay measurements between Proxies,

      -  on-path upstream and downstream loss and delay components (as
         explained in [I-D.ietf-ippm-explicit-flow-measurements]) on
         each Observer,

      -  on-path intra-domain loss and delay portion as a result of the
         difference between the computed upstream or downstream
         components (as explained in
         [I-D.ietf-ippm-explicit-flow-measurements]).

   In case of non-collaborating proxies, since Safe-to-Forward options
   that are not recognized MUST be forwarded, the enabled measurements
   can be:

   *  end-to-end loss and delay measurements between Client and Server,

   *  on-path upstream and downstream loss and delay components (as
      explained in [I-D.ietf-ippm-explicit-flow-measurements]) on each
      Observer,

   *  on-path intra-domain loss and delay portion as a result of the
      difference between the computed upstream or downstream components
      (as explained in [I-D.ietf-ippm-explicit-flow-measurements]).










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   If there are CoAP proxies, the measurement can be done between the
   Proxies or between a Proxy and the Client or between a Proxy and the
   Server.  It can be done through Spin bit or by applying
   [I-D.ietf-ippm-rfc8321bis] on the sQuare Bit signal.  Therefore, it
   is also possible to do hop-by-hop measurements for loss and delay and
   segment where possible according to the methodologies described in
   [I-D.ietf-ippm-explicit-flow-measurements].

   Since CoAP proxies hide the identity of the client and could also
   apply caching, on the server side the data would appear mixed in
   presence of more than one client doing the measurements.  Similarly,
   clients would receive mixed signals in presence of cache entries.
   But, as previously mentioned, the measurements can be segmented and
   done between the Proxies or between a Proxy and the Client or between
   a Proxy and the Server.  The Server can distinguish the source client
   by using additional flow information such as the IP addresses.  It
   could also be possible to bundle different clients if they are mixed.
   So, it is worth highlighting that an on-path observer can find useful
   information both on the client-proxy link and on proxy-server link:

      On the link from a proxy to the server, traffic from different
      clients would be mixed.  In this case, the proxy can still use the
      PM Option to set S bit and Q bit (or C bit) for the bundle of
      clients for a specific server.  The measurement can be done but it
      is an information related to a bundle of clients.  An alternative
      can be to use the Option only for a single client at once in order
      to avoid to do a grouped measurement.

      Conversely, on the link from the client to the proxy,
      communication may happen with different servers, and in this case
      it is necessary to check the other fields to understand the
      server.

5.3.  OSCORE

   CoAP PM Option can be used with OSCORE [RFC8613].  Since an OSCORE
   message may contain both an Inner and an Outer instance of a certain
   CoAP message field, the CoAP PM Option can be an Inner option or an
   Outer option based on the specific applications and required security
   and privacy.  Then the operators can put their measurement probes in
   one or more places to break down the different RTT and loss
   contributions where it is relevant (e.g. at the ingress/egress of
   their respective network segments).

   Inner option message fields (Class E) are used to communicate
   directly with the other endpoint and are encrypted and integrity
   protected.  If the CoAP PM Option is sent as Inner Option, it only
   enables end-to-end measurements.



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   Outer option message fields (Class U or I) are used to support proxy
   operations and are unprotected or integrity protected only.  If the
   CoAP PM Option is sent as Outer Option, it allows both end-to-end and
   on-path measurements by also enabling hop-by-hop and segmented
   measurements for loss and delay.

6.  Management and Configuration

   The measurement points can perform RTT and packet loss calculation
   without the need of any Network Management System (NMS) to collect
   information.  It may be possible that the measurement points inform
   the NMS if there are particular network conditions (e.g. high packet
   loss or high RTT).  For some parameters (e.g. 64 packets sQuare Bit
   signal) It is assumed static configuration on the client.  There are
   several alternatives for the implementation but this is out of scope
   of this document.

7.  Congestion Control

   As specified in [RFC7252], clients (including proxies) MUST strictly
   limit the number of simultaneous outstanding interactions that they
   maintain to a given server (including proxies) to NSTART.  The
   default value of NSTART is 1 but a value for NSTART greater than one
   is also possible.  The CoAP PM Option implementation must not affect
   CoAP congestion control mechanisms.

8.  Security Considerations

   Security considerations related to CoAP proxying are discussed in
   [RFC7252].

   A CoAP endpoint can use the CoAP PM Options to affect the measures of
   a network into which it is making requests by maliciously modifying
   the value of the option.  Also, the PM bits may reveal performance
   information outside the administrative domain.  To prevent that, a
   CoAP proxy that is located at the boundary of an administrative
   domain MAY be instructed to strip the payload or part of it before
   forwarding the message.

   It is worth highlighting what happens if devices, transport network
   and server are operated by different administrative domains.
   Security concerns need to be taken into account.

   CoAP can be secured using Datagram TLS (DTLS) [RFC6347] over UDP and
   it can prevent on-path measures in some cases.  When a client uses a
   proxy the session towards the proxy can be secured using DTLS and the
   same from there on.  In this case the separated sessions can still be
   measured.



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   CoAP can also be used with OSCORE [RFC8613] and the CoAP PM options
   can be integrity protected end-to-end by OSCORE.  In this case, as
   explained above and differently from DTLS, the CoAP PM can easily
   work with OSCORE.  OSCORE ensures end-to-end integrity protection and
   would tell the endpoints if someone tampered, but it doesn't mean
   that the endpoints are not lying to the observer.  However it is
   possible to assume that for the typical COAP applications it is less
   likely that the endpoints are attackers while it is more likely that
   an on-path observer is the attacker.

9.  IANA Considerations

   IANA is requested to add the following entry to the "CoAP Option
   Numbers" sub-registry available at https://www.iana.org/assignments/
   core-parameters/core-parameters.xhtml#option-numbers:

             Number          Name              Reference
             ---------------------------------------------
             TBD           PM Option          [This draft]

                      Figure 7: CoAP PM Option Numbers

10.  Acknowledgements

   The authors would like to thank Christian Amsuess, Carsten Bormann,
   Marco Tiloca, Thomas Fossati for the precious comments and
   suggestions.

11.  References

11.1.  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>.

   [RFC7252]  Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
              Application Protocol (CoAP)", RFC 7252,
              DOI 10.17487/RFC7252, June 2014,
              <https://www.rfc-editor.org/info/rfc7252>.

   [RFC8613]  Selander, G., Mattsson, J., Palombini, F., and L. Seitz,
              "Object Security for Constrained RESTful Environments
              (OSCORE)", RFC 8613, DOI 10.17487/RFC8613, July 2019,
              <https://www.rfc-editor.org/info/rfc8613>.

11.2.  Informative References



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   [I-D.ietf-ippm-explicit-flow-measurements]
              Cociglio, M., Ferrieux, A., Fioccola, G., Lubashev, I.,
              Bulgarella, F., Nilo, M., Hamchaoui, I., and R. Sisto,
              "Explicit Flow Measurements Techniques", Work in Progress,
              Internet-Draft, draft-ietf-ippm-explicit-flow-
              measurements-02, 13 October 2022,
              <https://www.ietf.org/archive/id/draft-ietf-ippm-explicit-
              flow-measurements-02.txt>.

   [I-D.ietf-ippm-rfc8321bis]
              Fioccola, G., Cociglio, M., Mirsky, G., Mizrahi, T., and
              T. Zhou, "Alternate-Marking Method", Work in Progress,
              Internet-Draft, draft-ietf-ippm-rfc8321bis-03, 25 July
              2022, <https://www.ietf.org/archive/id/draft-ietf-ippm-
              rfc8321bis-03.txt>.

   [RFC6347]  Rescorla, E. and N. Modadugu, "Datagram Transport Layer
              Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347,
              January 2012, <https://www.rfc-editor.org/info/rfc6347>.

   [RFC9000]  Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
              Multiplexed and Secure Transport", RFC 9000,
              DOI 10.17487/RFC9000, May 2021,
              <https://www.rfc-editor.org/info/rfc9000>.

   [RFC9312]  K├╝hlewind, M. and B. Trammell, "Manageability of the QUIC
              Transport Protocol", RFC 9312, DOI 10.17487/RFC9312,
              September 2022, <https://www.rfc-editor.org/info/rfc9312>.

Authors' Addresses

   Giuseppe Fioccola
   Huawei
   Riesstrasse, 25
   80992 Munich
   Germany
   Email: giuseppe.fioccola@huawei.com


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





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   Mauro Cociglio
   Telecom Italia
   Via Reiss Romoli, 274
   10148 Torino
   Italy
   Email: mauro.cociglio@outlook.com


   Fabio Bulgarella
   Telecom Italia
   Via Reiss Romoli, 274
   10148 Torino
   Italy
   Email: fabio.bulgarella@guest.telecomitalia.it


   Massimo Nilo
   Telecom Italia
   Via Reiss Romoli, 274
   10148 Torino
   Italy
   Email: massimo.nilo@telecomitalia.it





























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