TSVWG Working Group                                               L. Han
Internet-Draft                                                     Y. Qu
Intended status: Informational                                     R. Li
Expires: May 7, 2020                              Futurewei Technologies
                                                        November 4, 2019


                 Enhanced DiffServ by In-band Signaling
                  draft-han-tsvwg-enhanced-diffserv-00

Abstract

   There are real-time applications requiring deterministic services in
   terms of bandwidth and latency in various industries, such as network
   based AR/VR (Augmented Reality and Virtual Reality), industrial
   internet.  This document proposes a solution which enhances DiffServ
   in IPv6 to provide end to end bandwidth guaranteed service and
   latency guaranteed service.

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 May 7, 2020.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of



Han, et al.                Expires May 7, 2020                  [Page 1]


Internet-Draft              Enhanced DiffServ              November 2019


   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  DiffServ and IntServ  . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Differentiated Services . . . . . . . . . . . . . . . . .   4
     3.2.  Integrated Services . . . . . . . . . . . . . . . . . . .   5
   4.  In-band Signaling . . . . . . . . . . . . . . . . . . . . . .   5
   5.  Design Targets  . . . . . . . . . . . . . . . . . . . . . . .   5
   6.  Processing Procedure  . . . . . . . . . . . . . . . . . . . .   6
     6.1.  Introduction  . . . . . . . . . . . . . . . . . . . . . .   6
     6.2.  The purpose of in-band signaling  . . . . . . . . . . . .   7
     6.3.  The info carried in in-band signaling . . . . . . . . . .   7
     6.4.  Admission process with in-band signaling  . . . . . . . .   8
     6.5.  User traffic classification and New DSCP class  . . . . .   8
     6.6.  User traffic conformity checking  . . . . . . . . . . . .   9
     6.7.  Queuing and Scheduling Consideration  . . . . . . . . . .   9
     6.8.  Class Based Traffic Shaper  . . . . . . . . . . . . . . .  10
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  10
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  11
   Appendix A.  Acknowledgements . . . . . . . . . . . . . . . . . .  13
   Appendix B.  Testing Results  . . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   [RFC8557][RFC8578] identifies some use cases from different
   industries which have a common need for "deterministic flows".  Such
   flows require guaranteed bandwidth and bounded latency.

   This document proposes to use in-band signaling together with
   DiffServ to provide Latency Guaranteed Service and Bandwidth
   Guaranteed Service.  Network traffic is classified according to
   application requirements and resources such as bandwidth and buffer
   are dedicated to provide a reliable and scalable service, while
   unused reserved resources could be used by best effort traffic.

   The solution is compatible with existing Quality-of-Service (QoS)
   mechanism as long as there is enough network resources, and is not
   restricted to network topologies.  Resource Reservation is done by
   in-band signaling [I-D.han-tsvwg-ip-transport-qos], and IP path can




Han, et al.                Expires May 7, 2020                  [Page 2]


Internet-Draft              Enhanced DiffServ              November 2019


   be achieved using existing routing protocols (IGP or BPG), or the
   explicit path routing such as segment routing [RFC8402].

2.  Terminology

   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] RFC 8174 [RFC8174] when, and only when, they appear in
   all capitals, as shown here.

   Abbreviations used in this documents:

   E2E
         End-to-end.

   EH
         IPv6 Extension Header or Extension Option.

   QoS
         Quality of Service.

   OAM
         Operation and Management.

   In-band Signaling
         In telecommunications, in-band signaling is sending control
         information within the same band or channel used for voice or
         video.

   Out-of-band Signaling
         out-of-band signaling is that the control information sent over
         a different channel, or even over a separate network.

   IP flow
         For non-IPSec, an IP flow is identified by the source,
         destination IP address, the protocol number, the source and
         destination port number.

   IP path
         An IP path is the route that IP flow will traverse.  It could
         be the shortest path determined by routing protocols (IGP or
         BPG), or the explicit path such as segment routing [RFC8402].

   QoS channel
         A forwarding channel that is QoS guaranteed.  It provides
         additional QoS service to IP forwarding.  A QoS channel can be




Han, et al.                Expires May 7, 2020                  [Page 3]


Internet-Draft              Enhanced DiffServ              November 2019


         used for one or multiple IP flows depending on the granularity
         of in-band signaling.

   srTCM
         Single Rate Three Color Marker [RFC2697]

   trTCM
         Two Rate Three Color Marker [RFC4115]

   LGS
         Latency Guaranteed Service

   BGS
         Bandwidth Guaranteed Service

   BES
         Best Effort Service

   CIR
         Committed Information Rate.

   PIR
         Peak Information Rate.

   HbH-EH
         IPv6 Hop-by-Hop Extension Header.

   Dst-EH
         IPv6 Destination Extension Header.

   HbH-EH-aware node
         Network nodes that are configured to process the IPv6 Hop-by-
         Hop Extension Header.

3.  DiffServ and IntServ

3.1.  Differentiated Services

   Differentiated services or DiffServ [RFC2475] provides a simple,
   scalable and coarse-grained mechanism to support quality of services
   on IP networks by classifying and managing network traffic.

   DiffServ uses DiffServ Code Point (DSCP) which is the first 6 bits of
   the TOS field [RFC2474] to classify packets when they enter the
   network and then are separated into different queues.  With DiffServ
   each router handles each packet differently.  Per-Hop Forwarding
   Behavior (PHB) is a way of forwarding a particular flow or group of




Han, et al.                Expires May 7, 2020                  [Page 4]


Internet-Draft              Enhanced DiffServ              November 2019


   flows marked with a particular DSCP value using a particular method
   on a DiffServ node.

3.2.  Integrated Services

   IntServ [RFC3175] or integrated services specifies more fine-grained
   QoS, which is often contrasted with DiffServ's coarse-grained control
   system.  IntServ definitely can support the applications requiring
   special QoS guarantee if it is deployed in a network, supported by
   Host OS and integrated with application.  However, IntServ works on a
   small-scale only.  When you scale up the network, it is difficult to
   keep track of all of the reservations and session states.  Thus,
   IntServ is not scalable.  Another problem of IntServ is it is not
   application driven, tedious provisioning cross different network must
   be done earlier.  The provisioning is slow and hard to maintain.

4.  In-band Signaling

   In-band signaling messages are carried along with the payload, and it
   is guaranteed that the signaling follows the same path as the data
   flow.

   In-band QoS signaling for IPv6 was discussed by Lawrence Roberts in
   2005 [I-D.roberts-inband-qos-ipv6].  The requirements of IP in-band
   signaling was proposed by Jon Haper in 2007
   [I-D.harper-inband-signalling-requirements].  Telecommunications
   Industry Association (TIA) published a standard for "QoS Signaling
   for IP QoS Support and Sender Authentication" in 2006 [TIA].

   This draft uses the in-band signaling method proposed by
   [I-D.han-tsvwg-ip-transport-qos], which offers a solution in IPv6 for
   QoS service using in-band signaling to guarantee certain level of
   service quality.  Advantages of using in-band signaling and what
   parameters are carried etc. are discussed in great details.  Please
   refer to [I-D.han-tsvwg-ip-transport-qos] for signaling details,
   which is not in the scope of this document.

5.  Design Targets

   The design targets of the proposal are outlined as follows:

   1.  Service Guarantee:

       *  Provide guaranteed and minimized (queuing) latency for LGS
          (Latency Guaranteed Service) flows.  The maximum latency is
          guaranteed, minimized and predictable at each hop, if LGS flow
          rate is confirmed with their pre-claimed parameters
          (CIR,PIR,CBS,EBS).



Han, et al.                Expires May 7, 2020                  [Page 5]


Internet-Draft              Enhanced DiffServ              November 2019


       *  Provide guaranteed bandwidth for BGS (Bandwidth Guaranteed
          Service) flows.  The bandwidth of CIR is guaranteed at each
          hop, if BGS flow rate is confirmed with their pre-claimed
          parameters (CIR,PIR,CBS,EBS).

   2.  No Starvation: LGS flows will never starve other types of lower
       priority flows (BGS and BES).  BGS flows will never starve BE
       flows.

   3.  No sacrifice of link utilization: When the total rate of LGS flow
       is less than the committed rate (sum of CIR of all LGS flows),
       other class flows (BGS and BES) can use the remained bandwidth.
       When the total rate of LGS flow is less than the committed rate
       (sum of CIR of all LGS flows), and, the total rate of BGS flow is
       less than the committed rate (sum of CIR of all BGS flows), other
       class flows (BES) can use the remained bandwidth.

   4.  Fairness within the same class: All LGS flows will share the
       bandwidth within its class.  All BGS flows will share the
       bandwidth within its class.  All BE flows will share the
       bandwidth within BE class.

   5.  Backward compatible with current DiffServ, and can coexist and
       can be deployed incrementally.

6.  Processing Procedure

6.1.  Introduction

   The section will describe more details about the in-band signaling
   integrated with DiffServ to achieve the guaranteed service.  It is
   composed of following contents:

   1.  The purpose of in-band signaling for enhanced DiffServ.

   2.  The info carried in the signaling.

   3.  The admission process with in-band signaling.

   4.  User traffic classification.

   5.  User traffic classification and New DSCP class.

   6.  Queuing and Scheduling Consideration.

   7.  Class Based Traffic Shaper.





Han, et al.                Expires May 7, 2020                  [Page 6]


Internet-Draft              Enhanced DiffServ              November 2019


   The document [Enhanced_DSCP] has more details for the experiments
   using the proposal to achieve the latency guaranteed service.  The
   theoretical formula to estimate the maximum latency is given.
   Different tests with different combination of traffic are done.
   Results are analyzed and further researches are discussed.

6.2.  The purpose of in-band signaling

   The in-band signaling procedures described in
   [I-D.han-tsvwg-ip-transport-qos] is to make network support new
   services.  There are two types of new services provided:

   1.  Latency Guaranteed Service (LGS): Provide guaranteed and
       minimized queuing latency.  The maximum latency of a LGS flow is
       guaranteed, minimized and predictable at each hop if the LGS flow
       rate is confirmed with its pre-claimed parameters (CIR, PIR, CBS,
       EBS).

   2.  Bandwidth Guaranteed Service (BGS): provide guaranteed bandwidth.
       The CIR bandwidth of a BGS flow is guaranteed at each hop if the
       BGS flow rate is confirmed with its pre-claimed parameters.

   In addition to above, the use of in-band signaling with DiffServ will
   make the flow level QoS expectation available at each network device
   on the IP path.  Then network device could collect all flows
   signaling info to form an accurate instruction for QoS programming
   automatically.  Without such automation process, DiffServ will only
   be able to rely on the network management procedures to configure the
   QoS for each class at each hop one by one, this is called Per Hop
   Behavior.

6.3.  The info carried in in-band signaling

   The detailed info carried in the signaling was described in the draft
   [I-D.han-tsvwg-ip-transport-qos].

   In order to achieve the service guarantees, admission control is
   needed for user's service expectation.  Also to get the best service
   guarantee in network, some network device need to do traffic shaping
   to measure and control traffic for difference service.

   To satisfy above two requirements, each flow's service expectation
   and traffic pattern should be carried in the signaling.

   To describe one or multiple flows traffic character, Single Rate
   Three Color Marker (srTCM from [RFC2697]) or Two Rate Three Color
   Marker (trTCM from RFC4115) could be used.  The minimum requirement
   from user's signaling is the Cir (Committed information rate) when



Han, et al.                Expires May 7, 2020                  [Page 7]


Internet-Draft              Enhanced DiffServ              November 2019


   srTCM is used, CIR plus PIR (Peak information rate) when trTCM is
   used.  Optionally, the signaling can carry more info about the
   traffic, such as CBS, EBS.  The exact requirements for signaling will
   be decided by IETF.

6.4.  Admission process with in-band signaling

   The admission control should be enforced at any ingress interface
   connecting to user's device or accepting user's traffic, and also
   enforced at the egress interfaces that will send the user's traffic
   to next network device.  In addition to other irrelevant admission
   checking, the admission process for the E-DiffServ minimally has
   three major steps:

   1.  If a user is allowed to request the desired service described in
       its in-band signaling.  This may include the security,
       authentication and billing checks.

   2.  After adding the new flow for a user's request, if the total rate
       for all flows in the same class at the same ingress interface
       exceeds the total bandwidth allocated for the class for the
       ingress interface, this allocated bandwidth is from management
       procedures and is less than the ingress interface link rate.

   3.  After adding the new flow for a user's request, if the total rate
       for all flows in the same class at the same egress interface
       exceeds the total bandwidth allocated for the class for the
       egress interface, this allocated bandwidth is from management
       procedures and is less than the egress interface link rate.

   In above admission control process, if a flow is not allowed, the in-
   band signaling of the flow is updated accordingly to indicate the
   desired service is rejected, and the in-band signaling will finally
   notify the user's host.  If a flow is allowed, the in-band signaling
   of the flow will proceed to continue.  For the details of how the
   closed loop control is formed by in-band signaling, please refer to
   [I-D.han-tsvwg-ip-transport-qos].

6.5.  User traffic classification and New DSCP class

   After passed the admission control process, user's traffic is
   classified to different class based on its requested service.  This
   is also done at the ingress interface like the admission control.
   There are two options for the classification:

   1.  For a network without DiffServ enabled, the LGS flows can be
       classified as EF class to achieve the shortest latency; The BGS




Han, et al.                Expires May 7, 2020                  [Page 8]


Internet-Draft              Enhanced DiffServ              November 2019


       flows can be classified as any type of AFxy class; The BE flows
       can be classified as BE class.

   2.  For a network that DiffServ is enabled, the LGS and BGS flows can
       be classified as two new class; The BE flows can be classified as
       BE class.  To be backward compatible and not interrupting
       existing DiffServ services, new DSCP classes are proposed for LGS
       and BGS.  The values are TBD.

6.6.  User traffic conformity checking

   After a user's request service passes the admission control and is
   accepted, user's traffic is still needed to be checked for its
   conformity. i.e, if the traffic is conforming to the traffic pattern
   claimed in the service request.

   This is done by a traffic meter (shaper) associated to ingress
   interface.  The algorithm in the meter is using either srTCM or
   trTCM.  The action of the meter will determine what exact class the
   traffic will be classified as.  Only the Green traffic will be marked
   to the designated class described in 5.5.  Other colored traffic
   (Yellow or Red) will be classified as lower priority class or just
   discarded.  The exact action is up to the decision of IETF.

6.7.  Queuing and Scheduling Consideration

   The most important factor to provide the guaranteed service is the
   queuing and scheduling selection at egress interface on each router.
   There are many researches about this topic.  The current widely
   accepted methods are Class based Strict Priority Queuing (PQ) and
   Weighed Fair Queuing (WFQ).  It is recommended that the PQ+WFQ are
   used for different service flows.  PQ is the best candidate to
   provide the shortest latency for LGS flows.  The WFQ can be used for
   BGS flows.  There are two options for the Queuing and Scheduling
   selection:

   1.  For a network without DiffServ enabled, the LGS flows can be
       queued into the Highest Priority Queue to achieve the shortest
       latency; The BGS and BE flows can be queued into different
       Weighted Fair Queues to share bandwidth.  The weight for BGS can
       be obtained from the sum of all BGS flows' CIR.  The weight for
       BE can be calculated from the link rate deducting the bandwidth
       allocated for LGS and BGS flows.

   2.  For a network with DiffServ enabled, the LGS flows can be queued
       into the Secondary Highest Priority Queue just below EF queue;
       The BGS and BE flows can be queued into different Weighted Fair
       Queues to share bandwidth with other existing classes.  The



Han, et al.                Expires May 7, 2020                  [Page 9]


Internet-Draft              Enhanced DiffServ              November 2019


       weight for BGS can be obtained from the sum of all BGS flows'
       CIR.  The weight for BE can be calculated from the link rate
       deducting the bandwidth allocated for all AFxy classes, LGS and
       BGS flows.

6.8.  Class Based Traffic Shaper

   To guarantee each class's traffic are confirming to the pre-allocated
   bandwidth or resource for the class, class-based traffic shaper can
   be used for traffics before they are queued into different queues.
   Only Green traffic will be queued into the queue described above.
   Other colored traffic (Yellow or Red) will be queued into a lower
   priority queue or discard.  The exact actions will be decided by
   IETF.  The purpose of using traffic shaper for each class is to
   protect the service for each class when other class traffic is
   exceeding its allocation.  This is critical to satisfy the design
   target outlined in section 5.

   The algorithm for the shaper is similar to the ingress traffic shaper
   described in section 6.6.  The algorithm in the meter is using either
   srTCM or trTCM.

   The Traffic Shaper's Parameter such as PIR, CIR, CBS, EBS can be
   obtained from all flow's traffic parameters embedded into the in-band
   signaling. i.e, PIR or CIR can be calculated by the sum of all
   allowed (same class) flow's PIR or CIR values.  CBS and EBS can also
   be obtained from flow's signaling message if it carries, or from
   management process.  The detailed standard will be decided by IETF.

7.  IANA Considerations

   The new DSCP values are required to be allocated by IANA.

8.  Security Considerations

   TBD.

9.  References

9.1.  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>.






Han, et al.                Expires May 7, 2020                 [Page 10]


Internet-Draft              Enhanced DiffServ              November 2019


   [RFC2581]  Allman, M., Paxson, V., and W. Stevens, "TCP Congestion
              Control", RFC 2581, DOI 10.17487/RFC2581, April 1999,
              <https://www.rfc-editor.org/info/rfc2581>.

   [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>.

   [RFC8200]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", STD 86, RFC 8200,
              DOI 10.17487/RFC8200, July 2017,
              <https://www.rfc-editor.org/info/rfc8200>.

9.2.  Informative References

   [Enhanced_DSCP]
              "Enhanced DSCP by In-band Signaling", 2018,
              <https://drive.google.com/file/d/
              1aBq4z70iJgbKZIBn7TTieQUhZ7MPYOsn/view?usp=sharing>.

   [EPC]      3GPP, "The Evolved Packet Core", 2018,
              <http://www.3gpp.org/technologies/keywords-acronyms/ 100-
              the-evolved-packet-core>.

   [HU5G]     Huawei, "5G Vision: 100 Billion connections, 1 ms Latency,
              and 10 Gbps Throughput", 2015,
              <http://www.huawei.com/minisite/5g/en/defining-5g.html>.

   [I-D.falk-xcp-spec]
              Falk, A., "Specification for the Explicit Control Protocol
              (XCP)", draft-falk-xcp-spec-03 (work in progress), July
              2007.

   [I-D.han-iccrg-arvr-transport-problem]
              Han, L. and K. Smith, "Problem Statement: Transport
              Support for Augmented and Virtual Reality Applications",
              draft-han-iccrg-arvr-transport-problem-01 (work in
              progress), March 2017.

   [I-D.han-tsvwg-cc]
              Han, L., Qu, Y., and T. Nadeau, "A New Congestion Control
              in Bandwidth Guaranteed Network", draft-han-tsvwg-cc-00
              (work in progress), March 2018.








Han, et al.                Expires May 7, 2020                 [Page 11]


Internet-Draft              Enhanced DiffServ              November 2019


   [I-D.han-tsvwg-ip-transport-qos]
              Han, L., Qu, Y., Dong, L., Li, R., Nadeau, T., Smith, K.,
              and J. Tantsura, "Resource Reservation Protocol for IP
              Transport QoS", draft-han-tsvwg-ip-transport-qos-03 (work
              in progress), October 2019.

   [I-D.harper-inband-signalling-requirements]
              Harper, J., "Requirements for In-Band QoS Signalling",
              draft-harper-inband-signalling-requirements-00 (work in
              progress), January 2007.

   [I-D.ietf-tcpm-dctcp]
              Bensley, S., Eggert, L., Thaler, D., Balasubramanian, P.,
              and G. Judd, "Datacenter TCP (DCTCP): TCP Congestion
              Control for Datacenters", draft-ietf-tcpm-dctcp-03 (work
              in progress), November 2016.

   [I-D.roberts-inband-qos-ipv6]
              Roberts, L. and J. Harford, "In-Band QoS Signaling for
              IPv6", draft-roberts-inband-qos-ipv6-00 (work in
              progress), July 2005.

   [I-D.sridharan-tcpm-ctcp]
              Sridharan, M., Tan, K., Bansal, D., and D. Thaler,
              "Compound TCP: A New TCP Congestion Control for High-Speed
              and Long Distance Networks", draft-sridharan-tcpm-ctcp-02
              (work in progress), November 2008.

   [IPv6_Parameters]
              IANA, "Internet Protocol Version 6 (IPv6) Parameters",
              2015, <https://www.iana.org/assignments/ipv6-parameters/
              ipv6-parameters.xhtml#ipv6-parameters-2>.

   [QU2016]   Qualcomm, "Leading the world to 5G", 2016,
              <https://www.qualcomm.com/media/documents/files/qualcomm-
              5g-vision-presentation.pdf>.

   [RFC2474]  Nichols, K., Blake, S., Baker, F., and D. Black,
              "Definition of the Differentiated Services Field (DS
              Field) in the IPv4 and IPv6 Headers", RFC 2474,
              DOI 10.17487/RFC2474, December 1998,
              <https://www.rfc-editor.org/info/rfc2474>.

   [RFC2475]  Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
              and W. Weiss, "An Architecture for Differentiated
              Services", RFC 2475, DOI 10.17487/RFC2475, December 1998,
              <https://www.rfc-editor.org/info/rfc2475>.




Han, et al.                Expires May 7, 2020                 [Page 12]


Internet-Draft              Enhanced DiffServ              November 2019


   [RFC2697]  Heinanen, J. and R. Guerin, "A Single Rate Three Color
              Marker", RFC 2697, DOI 10.17487/RFC2697, September 1999,
              <https://www.rfc-editor.org/info/rfc2697>.

   [RFC3175]  Baker, F., Iturralde, C., Le Faucheur, F., and B. Davie,
              "Aggregation of RSVP for IPv4 and IPv6 Reservations",
              RFC 3175, DOI 10.17487/RFC3175, September 2001,
              <https://www.rfc-editor.org/info/rfc3175>.

   [RFC4115]  Aboul-Magd, O. and S. Rabie, "A Differentiated Service
              Two-Rate, Three-Color Marker with Efficient Handling of
              in-Profile Traffic", RFC 4115, DOI 10.17487/RFC4115, July
              2005, <https://www.rfc-editor.org/info/rfc4115>.

   [RFC8402]  Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
              Decraene, B., Litkowski, S., and R. Shakir, "Segment
              Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
              July 2018, <https://www.rfc-editor.org/info/rfc8402>.

   [RFC8557]  Finn, N. and P. Thubert, "Deterministic Networking Problem
              Statement", RFC 8557, DOI 10.17487/RFC8557, May 2019,
              <https://www.rfc-editor.org/info/rfc8557>.

   [RFC8578]  Grossman, E., Ed., "Deterministic Networking Use Cases",
              RFC 8578, DOI 10.17487/RFC8578, May 2019,
              <https://www.rfc-editor.org/info/rfc8578>.

   [TIA]      TIA 1039 Revision A, "QoS Signaling for IP QoS Support and
              Sender Authentication", 2015, <https://global.ihs.com/doc_
              detail.cfm?&csf=TIA&item_s_key=00480715&item_key_date=8804
              31>.

Appendix A.  Acknowledgements

   TBD.

Appendix B.  Testing Results

   The analysis of the queuing delay and testing results can be found at
   [Enhanced_DSCP] .

Authors' Addresses









Han, et al.                Expires May 7, 2020                 [Page 13]


Internet-Draft              Enhanced DiffServ              November 2019


   Lin Han
   Futurewei Technologies
   2330 Central Expressway
   Santa Clara, CA  95050
   USA

   Email: lin.han@futurewei.com


   Yingzhen Qu
   Futurewei Technologies
   2330 Central Expressway
   Santa Clara, CA  95050
   USA

   Email: yingzhen.qu@futurewei.com


   Richard Li
   Futurewei Technologies
   2330 Central Expressway
   Santa Clara, CA  95050
   USA

   Email: richard.li@futurewei.com


























Han, et al.                Expires May 7, 2020                 [Page 14]