Application of Explicit Measurement Techniques for QUIC Troubleshooting
draft-mdt-quic-explicit-measurements-03

QUIC                                                    A. Ferrieux, Ed.
Internet-Draft                                               Orange Labs
Intended status: Standards Track                        I. Lubashev, Ed.
Expires: 5 March 2026                                Akamai Technologies
                                                        G. Fioccola, Ed.
                                                     Huawei Technologies
                                                           M. Ihlar, Ed.
                                                                Ericsson
                                                           F. Bulgarella
                                                    Telecom Italia - TIM
                                                             M. Cociglio
                                                                        
                                                            I. Hamchaoui
                                                             Orange Labs
                                                                 M. Nilo
                                                    Telecom Italia - TIM
                                                        1 September 2025

Application of Explicit Measurement Techniques for QUIC Troubleshooting
                draft-mdt-quic-explicit-measurements-03

Abstract

   This document defines a protocol that can be used by QUIC endpoints
   to signal packet loss in a way that can be used by network devices to
   measure and locate the source of the loss.

   Discussion of this work is encouraged to happen on the QUIC IETF
   mailing list quic@ietf.org (mailto:quic@ietf.org) or on the GitHub
   repository which contains the draft: https://github.com/igorlord/
   draft-mdt-quic-explicit-measurements (https://github.com/igorlord/
   draft-mdt-quic-explicit-measurements).

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
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   Internet-Drafts are draft documents valid for a maximum of six months
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   This Internet-Draft will expire on 5 March 2026.

Copyright Notice

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   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Notational Conventions  . . . . . . . . . . . . . . . . .   3
   2.  On-Path RTT Observation . . . . . . . . . . . . . . . . . . .   4
   3.  On-Path Loss Observation  . . . . . . . . . . . . . . . . . .   4
     3.1.  On-Path Loss Signaling Protocol . . . . . . . . . . . . .   4
     3.2.  Recommended Use of the Signals  . . . . . . . . . . . . .   5
   4.  Loss Bits . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     4.1.  Setting the sQuare Signal Bit on Outgoing Packets . . . .   5
       4.1.1.  Q Run Length Selection  . . . . . . . . . . . . . . .   5
     4.2.  Setting the Loss Event Bit on Outgoing Packets  . . . . .   6
   5.  Using Loss Bits for Passive Loss Measurement  . . . . . . . .   6
     5.1.  End-To-End Loss . . . . . . . . . . . . . . . . . . . . .   7
     5.2.  Upstream Loss . . . . . . . . . . . . . . . . . . . . . .   7
     5.3.  Correlating End-to-End and Upstream Loss  . . . . . . . .   7
     5.4.  Downstream Loss . . . . . . . . . . . . . . . . . . . . .   8
     5.5.  Observer Loss . . . . . . . . . . . . . . . . . . . . . .   8
   6.  Implementation  . . . . . . . . . . . . . . . . . . . . . . .   8
     6.1.  EFMP Packet . . . . . . . . . . . . . . . . . . . . . . .   8
     6.2.  Transport Parameter . . . . . . . . . . . . . . . . . . .  10
     6.3.  EFMP Packet Processing  . . . . . . . . . . . . . . . . .  10
   7.  Ossification Considerations . . . . . . . . . . . . . . . . .  10
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
     8.1.  Optimistic ACK Attack . . . . . . . . . . . . . . . . . .  11
   9.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .  11
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12
   11. Change Log  . . . . . . . . . . . . . . . . . . . . . . . . .  12
   12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  12
   13. References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     13.1.  Normative References . . . . . . . . . . . . . . . . . .  12
     13.2.  Informative References . . . . . . . . . . . . . . . . .  13

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   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   Packet loss is a hard and pervasive problem of day-to-day network
   operation.  Proactively detecting, measuring, and locating it is
   crucial to maintaining high QoS and timely resolution of crippling
   end-to-end throughput issues.  To this effect, in a TCP-dominated
   world, network operators have been heavily relying on information
   present in the clear in TCP headers: sequence and acknowledgment
   numbers, and SACKs when enabled.  These allow for quantitative
   estimation of packet loss by passive on-path observation.

   With QUIC, the equivalent transport headers are encrypted, and
   passive packet loss observation is not possible, as described in
   [RFC9065].

   Measuring TCP loss between similar endpoints cannot be relied upon to
   evaluate QUIC loss.  QUIC could be routed by the network differently
   and the fraction of Internet traffic delivered using QUIC is
   increasing every year.  It is imperative to measure packet loss
   experienced by QUIC users directly.

   The Alternate-Marking method [AltMark] defines a consolidated method
   to perform packet loss, delay, and jitter measurements on live
   traffic.  However, as noted in [EXPLICIT-MEASUREMENTS], applying
   [AltMark] to end-to-end transport-layer connections is not easy
   because packet identification and marking by network nodes is
   prevented when QUIC encrypted transport-layer header is being used.

   This document defines the Explicit Flow Measurement Protocol (EFMP)
   which is used by QUIC endpoints to enable packet loss measurements
   using Explicit Host-to-Network Flow Measurement Techniques defined in
   [EXPLICIT-MEASUREMENTS].

   Measurement bits are sent in dedicated EFMP packets that are
   coalesced with other QUIC packets in UDP datagrams.

1.1.  Notational Conventions

   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 [RFC2119].

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2.  On-Path RTT Observation

   [QUIC-TRANSPORT] already introduces an explicit per-flow transport-
   layer signal for hybrid measurement of RTT.  This signal consists of
   a Spin bit that toggles once per RTT.

3.  On-Path Loss Observation

   There are three sources of loss that network operators need to
   observe to guarantee high QoS:

   *  _upstream loss_ - loss between the sender and the observation
      point (Section 5.2)

   *  _downstream loss_ - loss between the observation point and the
      destination (Section 5.4)

   *  _observer loss_ - loss by the observer itself that does not cause
      downstream loss (Section 5.5)

   The upstream and downstream loss together constitute _end-to-end
   loss_ (Section 5.1).

3.1.  On-Path Loss Signaling Protocol

   [EXPLICIT-MEASUREMENTS] introduces several techniques for using
   explicit loss bits in the clear portion of transport protocol headers
   to signal packet loss to on-path network devices.  The explicit loss
   bits used in this document are the "sQuare signal" bit (Q) and the
   "Loss event" bit (L) (see Section 4.1 and Section 4.2).  This
   approach follows the recommendations of [RFC8558] that recommends
   explicit path signals.

   This document defines the Explicit Flow Measurement Protocol (EFMP)
   that takes inspiration from [SCONE] that uses QUIC Long Header
   packets that are prepended to QUIC v1 or v2 packets as carriers of
   path signals.

   While the exploitation of only Q can help in measuring the _upstream
   loss_ and only L can help in measuring the _end-to-end loss_, both
   are required to detect and measure the other types of losses
   (_downstream loss_ and _observer loss_).

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3.2.  Recommended Use of the Signals

   The loss signal is not designed for use in automated control of the
   network in environments where loss bits are set by untrusted hosts.
   Instead, the signal is to be used for troubleshooting individual
   flows and for monitoring the network by aggregating information from
   multiple flows and raising operator alarms if aggregate statistics
   indicate a potential problem.

4.  Loss Bits

   The draft introduces two bits that are to be present in EFMP packets.

   *  Q: The "sQuare signal" bit is toggled every N outgoing packets, as
      explained below in Section 4.1.

   *  L: The "Loss event" bit is set to 0 or 1 according to the
      Unreported Loss counter, as explained below in Section 4.2.

   Each endpoint maintains appropriate counters independently and
   separately for each connection 4-tuple and Destination Connection ID.
   Whenever this specification refers to connections, it is referring to
   packets sharing the same 4-tuple and Destination Connection ID.  A
   "QUIC connection", however, refers to connections in the traditional
   QUIC sense.

4.1.  Setting the sQuare Signal Bit on Outgoing Packets

   The sQuare bit (Q bit) takes its name from the square wave generated
   by its signal.  This method is based on the Alternate-Marking method
   [AltMark].  The sQuare Value is initialized to the Initial Q Value (0
   or 1) and is reflected in the Q bit of every outgoing packet.  The
   sQuare value is inverted after sending every N packets (a Q run).
   Hence, Q Period is 2*N.  The Q bit represents "packet color" as
   defined by [RFC8321].

   Observation points can estimate upstream losses by counting the
   number of packets during one period of the square signal, as
   described in Section 5.

4.1.1.  Q Run Length Selection

   The sender is expected to choose N (Q run length) based on the
   expected amount of loss and reordering on the path.  The choice of N
   strikes a compromise -- the observation could become too unreliable
   in case of packet reordering and/or severe loss if N is too small,
   while short connections may not yield a useful upstream loss
   measurement if N is too large (see Section 5.2).

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   The value of N MUST be at least 64 and be a power of 2.  This
   requirement allows an Observer to infer the Q run length by observing
   one period of the square signal.  It also allows the Observer to
   identify flows that set the loss bits to arbitrary values (see
   Section 7).

   If the sender does not have sufficient information to make an
   informed decision about Q run length, the sender SHOULD use N=64,
   since this value has been extensively tested in large-scale field
   tests and yielded good results.  Alternatively, the sender MAY also
   choose a random N for each connection, increasing the chances of
   using a Q run length that gives the best signal for some connections.

   The sender MUST keep the value of N constant for a given connection.
   The sender can change the value of N during a QUIC connection by
   switching to a new Destination Connection ID, if one is available.

4.2.  Setting the Loss Event Bit on Outgoing Packets

   The Loss Event bit uses the Unreported Loss counter maintained by the
   QUIC protocol.  The Unreported Loss counter is initialized to 0, and
   the L bit of every outgoing packet indicates whether the Unreported
   Loss counter is positive (L=1 if the counter is positive, and L=0
   otherwise).  The value of the Unreported Loss counter is decremented
   every time a packet with L=1 is sent.

   The value of the Unreported Loss counter is incremented for every
   packet that the protocol declares lost, using QUIC's existing loss
   detection machinery.  If the implementation is able to rescind the
   loss determination later, a positive Unreported Loss counter MAY be
   decremented due to the rescission, but it SHOULD NOT become negative.

   This loss signaling is similar to loss signaling in [RFC7713], except
   the Loss Event bit is reporting the exact number of lost packets,
   whereas the Echo Loss bit in [RFC7713] is reporting an approximate
   number of lost bytes.

   Observation points can estimate the end-to-end loss, as determined by
   the upstream endpoint, by counting packets in this direction with the
   L bit equal to 1, as described in Section 5.

5.  Using Loss Bits for Passive Loss Measurement

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5.1.  End-To-End Loss

   The Loss Event bit allows an observer to calculate the end-to-end
   loss rate by counting packets with the L bit value of 0 and 1 for a
   given connection.  The end-to-end loss rate is the fraction of
   packets with L=1.

   The assumption here is that upstream loss affects packets with L=0
   and L=1 equally.  If some loss is caused by tail-drop in a network
   device, this may be a simplification.  If the sender congestion
   controller reduces the packet send rate after loss, there may be a
   sufficient delay before sending packets with L=1 that they have a
   greater chance of arriving at the observer.

5.2.  Upstream Loss

   Blocks of N (Q run length) consecutive packets are sent with the same
   value of the Q bit, followed by another block of N packets with an
   inverted value of the Q bit.  Hence, knowing the value of N, an on-
   path observer can estimate the amount of loss after observing at
   least N packets.  The upstream loss rate (u) is one minus the average
   number of packets in a block of packets with the same Q value (p)
   divided by N (u=1-avg(p)/N).

   The observer needs to be able to tolerate packet reordering that can
   blur the edges of the square signal.

   The observer needs to differentiate packets as belonging to different
   connections, since they use independent counters.

5.3.  Correlating End-to-End and Upstream Loss

   Upstream loss is calculated by observing packets that did not suffer
   the upstream loss.  End-to-end loss, however, is calculated by
   observing subsequent packets after the sender's protocol detected the
   loss.  Hence, end-to-end loss is generally observed with a delay of
   between 1 RTT (loss declared due to multiple duplicate
   acknowledgments) and 1 RTO (loss declared due to a timeout) relative
   to the upstream loss.

   The connection RTT can sometimes be estimated by timing protocol
   handshake messages.  This RTT estimate can be greatly improved by
   observing a dedicated protocol mechanism for conveying RTT
   information, such as the latency Spin bit of [QUIC-TRANSPORT].

   Whenever the observer needs to perform a computation that uses both
   upstream and end-to-end loss rate measurements, it SHOULD use
   upstream loss rate leading the end-to-end loss rate by approximately

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   1 RTT.  If the observer is unable to estimate RTT of the connection,
   it should accumulate loss measurements over time periods of at least
   4 times the typical RTT for the observed connections.

   If the calculated upstream loss rate exceeds the end-to-end loss rate
   calculated in Section 5.1, then either the Q run length is too short
   for the amount of packet reordering or there is observer loss,
   described in Section 5.5.  If this happens, the observer SHOULD
   adjust the calculated upstream loss rate to match end-to-end loss
   rate.

5.4.  Downstream Loss

   Because downstream loss affects only those packets that did not
   suffer upstream loss, the end-to-end loss rate (e) relates to the
   upstream loss rate (u) and downstream loss rate (d) as
   (1-u)(1-d)=1-e.  Hence, d=(e-u)/(1-u).

5.5.  Observer Loss

   A typical deployment of a passive observation system includes a
   network tap device that mirrors network packets of interest to a
   device that performs analysis and measurement on the mirrored
   packets.  The observer loss is the loss that occurs on the mirror
   path.

   Observer loss affects upstream loss rate measurement, since it causes
   the observer to account for fewer packets in a block of identical Q
   bit values (see Section 5.2).  The end-to-end loss rate measurement,
   however, is unaffected by the observer loss, since it is a
   measurement of the fraction of packets with the set L bit value, and
   the observer loss would affect all packets equally (see Section 5.1).

   The need to adjust the upstream loss rate down to match end-to-end
   loss rate as described in Section 5.3 is a strong indication of the
   observer loss, whose magnitude is between the amount of such
   adjustment and the entirety of the upstream loss measured in
   Section 5.2.  Alternatively, a high apparent upstream loss rate could
   be an indication of significant reordering, possibly due to packets
   belonging to a single connection being multiplexed over several
   upstream paths with different latency characteristics.

6.  Implementation

6.1.  EFMP Packet

   An EFMP packet is a QUIC long header packet that follows the QUIC
   invariants; see Section 5.1 of [INVARIANTS].

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   Figure 1 shows the format of the EFMP packet using the conventions
   from Section 4 of [INVARIANTS].

   EFMP Packet {
     Header Form (1) = 1,
     Reserved (1),
     Q Bit (1),
     L Bit (1),
     Spin Bit (1),
     Reserved (3),
     Version (32) = 0xTBD,
     Destination Connection ID Length (8),
     Destination Connection ID (0..2040),
     Source Connection ID Length (8),
     Source Connection ID (0..2040),
   }

                        Figure 1: EFMP Packet Format

   The most significant bit (0x80) of the packet indicates that this is
   a QUIC long header packet.  The next bit (0x40) is reserved and can
   be set according to [QUIC-BIT].

   The six least significant bits of the first octet of an EFMP packet
   forms the EFMP payload:

   sQuare Signal Bit (Q):  The first bit of the EFMP payload (0x20) is
      is the sQuare signal bit, set as described in Section 4.1.

   Loss Event Bit (L):  The second bit (0x10) is the Loss event bit, set
      as described in Section 4.2.

   Latency Spin Bit (S):  The third bit (0x8) is the latency spin bit.
      This bit is set to the value of the spin bit in the QUIC Short
      Header packet that follows directly after the EFMP packet in the
      same UDP datagram.

   The three least significant bits (0x7) are reserved for future use.

   An EFMP packet includes a Destination Connection ID field that is set
   to the same value as other packets in the same datagram; see
   Section 12.2 of [QUIC-TRANSPORT].

   The Source Connection ID field is set to match the Source Connection
   ID field of any packet that follows.  If the next packet in the
   datagram has a short header (Section 5.2 of [INVARIANTS]), the Source
   Connection ID field is empty.

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   EFMP packets are always coalesced with other QUIC packets and SHOULD
   be included as the first packet in a UDP datagram.

6.2.  Transport Parameter

   A QUIC endpoint indicates that it is willing to receive EFMP packets
   by including the transport parameter:

   efmp_supported (0xTBD):  efmp_supported transport parameter is an
      integer value, encoded as a variable-length integer, that can be
      set to 0 or 1, indicating the level of EFMP support.  The value of
      0 indicates that the endpoint is able to receive EFMP packets but
      will not be sending any, while the value of 1 indicates that the
      endpoint is also willing to send EFMP packets.

   A client MUST NOT use remembered value of efmp_supported for 0-RTT
   connections.

   Except for the cases outlined in Section 7, it is RECOMMENDED for the
   server to consistently include the efmp_supported parameter.  This
   enables clients to utilize loss bits at their discretion.

6.3.  EFMP Packet Processing

   An EFMP packet is identified by the header form bit (0x80) of the
   first byte of a UDP datagram payload and the 32-bit version field
   with the value (0xTBD) that directly follows the first octet.  Since
   the EFMP payload is part of the first octet, an observer does not
   need to process a packet beyond the version field.

7.  Ossification Considerations

   Accurate loss reporting is not critical for the operation of the QUIC
   protocol, though its presence in a sufficient number of connections
   is important for the operation of networks.

   The use of EFMP is amenable to "greasing" described in [RFC8701] and
   MUST be greased.  The greasing should be accomplished similarly to
   the latency Spin bit greasing in [QUIC-TRANSPORT].  Namely,
   implementations MUST NOT include efmp_supported transport parameter
   for a random selection of at least one in every 16 QUIC connections.

   It is possible to observe packet reordering near the edge of the
   square signal.  A middle box might observe the signal and try to fix
   packet reordering that it can identify, though only a small fraction
   of reordering can be fixed using this method.  The Latency Spin bit
   signal edge can be used for the same purpose.

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8.  Security Considerations

   The measurements described in this document do not involve new
   packets injected into the network causing potential harm to the
   network itself and to data traffic.  The measurements could be harmed
   by a malicious endpoint misreporting losses or an attacker injecting
   artificial traffic.  In the environments where such attacks are
   possible and cannot be identified by on-path observers, loss signal
   should not be used for automated control of the network.

   In the absence of packet loss, the Q bit signal does not provide any
   information that cannot be observed by simply counting packets
   transiting a network path.  The L bit signal discloses internal state
   of the protocol's loss detection machinery, but this state can often
   be gleaned by timing packets and observing congestion controller
   response.  Hence, loss bits do not provide a viable new mechanism to
   attack QUIC data integrity and secrecy.

8.1.  Optimistic ACK Attack

   A defense against an Optimistic ACK Attack [QUIC-TRANSPORT] involves
   a sender randomly skipping packet numbers to detect a receiver
   acknowledging packet numbers that have never been received.  The Q
   bit signal may inform the attacker which packet numbers were skipped
   on purpose and which had been actually lost (and are, therefore, safe
   for the attacker to acknowledge).  To use the Q bit for this purpose,
   the attacker must first receive at least an entire Q run of packets,
   which renders the attack ineffective against a delay-sensitive
   congestion controller.

   For QUIC v1 connections, if the attacker can make its peer transmit
   data using a single large stream, examining offsets in STREAM frames
   can reveal whether packet number skips are deliberate.  In that case,
   the Q bit signal provides no new information (but it does save the
   attacker the need to remove packet protection).  However, an endpoint
   that communicates using [DATAGRAM] and uses a loss-based congestion
   controller MAY shorten the current Q run by the number of skipped
   packets.  For example, skipping a single packet number will invert
   the sQuare signal one outgoing packet sooner.

9.  Privacy Considerations

   To minimize unintentional exposure of information, loss bits provide
   an explicit loss signal -- a preferred way to share information per
   [RFC8558].

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   [QUIC-TRANSPORT] allows changing connection IDs in the middle of a
   QUIC connection to reduce the likelihood of a passive observer
   linking old and new subflows to the same device.  Hence, a QUIC
   implementation would need to reset all counters when it changes
   connection ID used for outgoing packets.  It would also need to avoid
   incrementing Unreported Loss counter for loss of packets sent with a
   different connection ID.

   Accurate loss information allows identification and correlation of
   network conditions upstream and downstream of the observer.  This
   could be a powerful tool to identify connections that attempt to hide
   their origin networks, if the adversary is able to affect network
   conditions in those origin networks.  Similar information can be
   obtained by packet timing and inferring congestion controller
   response to network events, but loss information provides a clearer
   signal.

   Implementations MUST allow administrators of clients and servers to
   disable loss reporting either globally or per QUIC connection.
   Additionally, as described in Section 7, loss reporting MUST be
   disabled for a certain fraction of all QUIC connections.

10.  IANA Considerations

   This document registers a new value in the QUIC Transport Parameter
   Registry:

   Value: 0xTBD (if this document is approved)

   Parameter Name: efmp_supported

   Specification: Indicates that the endpoint supports the explicit flow
   measurement protocol.  An endpoint that advertises this transport
   parameter can EFMP packets.  An endpoint that advertises this
   transport parameter with value 1 can also send EFMP packets.

11.  Change Log

   TBD

12.  Acknowledgments

   The following people directly contributed key ideas that shaped this
   draft: Kazuho Oku, Christian Huitema.

13.  References

13.1.  Normative References

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   [AltMark]  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/rfc/rfc9341>.

   [EXPLICIT-MEASUREMENTS]
              Cociglio, M., Ferrieux, A., Fioccola, G., Lubashev, I.,
              Bulgarella, F., Nilo, M., Hamchaoui, I., and R. Sisto,
              "Explicit Host-to-Network Flow Measurements Techniques",
              RFC 9506, DOI 10.17487/RFC9506, October 2023,
              <https://www.rfc-editor.org/rfc/rfc9506>.

   [INVARIANTS]
              Thomson, M., "Version-Independent Properties of QUIC",
              RFC 8999, DOI 10.17487/RFC8999, May 2021,
              <https://www.rfc-editor.org/rfc/rfc8999>.

   [QUIC-BIT] Thomson, M., "Greasing the QUIC Bit", RFC 9287,
              DOI 10.17487/RFC9287, August 2022,
              <https://www.rfc-editor.org/rfc/rfc9287>.

   [QUIC-TRANSPORT]
              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/rfc/rfc9000>.

   [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/rfc/rfc2119>.

   [RFC8558]  Hardie, T., Ed., "Transport Protocol Path Signals",
              RFC 8558, DOI 10.17487/RFC8558, April 2019,
              <https://www.rfc-editor.org/rfc/rfc8558>.

   [RFC8701]  Benjamin, D., "Applying Generate Random Extensions And
              Sustain Extensibility (GREASE) to TLS Extensibility",
              RFC 8701, DOI 10.17487/RFC8701, January 2020,
              <https://www.rfc-editor.org/rfc/rfc8701>.

   [RFC9065]  Fairhurst, G. and C. Perkins, "Considerations around
              Transport Header Confidentiality, Network Operations, and
              the Evolution of Internet Transport Protocols", RFC 9065,
              DOI 10.17487/RFC9065, July 2021,
              <https://www.rfc-editor.org/rfc/rfc9065>.

13.2.  Informative References

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Internet-Draft            explicit-measurements           September 2025

   [DATAGRAM] Pauly, T., Kinnear, E., and D. Schinazi, "An Unreliable
              Datagram Extension to QUIC", RFC 9221,
              DOI 10.17487/RFC9221, March 2022,
              <https://www.rfc-editor.org/rfc/rfc9221>.

   [RFC7713]  Mathis, M. and B. Briscoe, "Congestion Exposure (ConEx)
              Concepts, Abstract Mechanism, and Requirements", RFC 7713,
              DOI 10.17487/RFC7713, December 2015,
              <https://www.rfc-editor.org/rfc/rfc7713>.

   [RFC8321]  Fioccola, G., Ed., Capello, A., Cociglio, M., Castaldelli,
              L., Chen, M., Zheng, L., Mirsky, G., and T. Mizrahi,
              "Alternate-Marking Method for Passive and Hybrid
              Performance Monitoring", RFC 8321, DOI 10.17487/RFC8321,
              January 2018, <https://www.rfc-editor.org/rfc/rfc8321>.

   [SCONE]    Thomson, M., Huitema, C., Oku, K., Joras, M., and L. M.
              Ihlar, "Standard Communication with Network Elements
              (SCONE) Protocol", Work in Progress, Internet-Draft,
              draft-ietf-scone-protocol-02, 7 July 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-scone-
              protocol-02>.

Authors' Addresses

   Alexandre Ferrieux (editor)
   Orange Labs
   Email: alexandre.ferrieux@orange.com

   Igor Lubashev (editor)
   Akamai Technologies
   Email: ilubashe@akamai.com

   Giuseppe Fioccola (editor)
   Huawei Technologies
   Email: giuseppe.fioccola@huawei.com

   Marcus Ihlar (editor)
   Ericsson
   Email: marcus.ihlar@ericsson.com

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

   Mauro Cociglio
   Italy
   Email: mauro.cociglio@outlook.com

   Isabelle Hamchaoui
   Orange Labs
   Email: isabelle.hamchaoui@orange.com

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

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