



hpwan                                                           Q. Xiong
Internet-Draft                                                  G. Huang
Intended status: Standards Track                         ZTE Corporation
Expires: 12 December 2025                                         K. Yao
                                                            China Mobile
                                                                  C. Lin
                                                    New H3C Technologies
                                                            10 June 2025


       Framework for High Performance Wide Area Network (HP-WAN)
                      draft-xhy-hpwan-framework-02

Abstract

   This document defines a framework to enable the host-network
   collaboration for high-speed and high-throughput data transmission,
   coupled with fast completion time of High Performance Wide Area
   Networks (HP-WAN).  It focuses on key congestion control functions to
   facilitate host-to-network collaboration and perform rate
   negotiation, such as QoS policy, admission control, and traffic
   scheduling.

Status of This Memo

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   This Internet-Draft will expire on 12 December 2025.

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   This document is subject to BCP 78 and the IETF Trust's Legal
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   license-info) in effect on the date of publication of this document.



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   Please review these documents carefully, as they describe your rights
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Definition of Terms . . . . . . . . . . . . . . . . . . . . .   3
   3.  Framework for HP-WAN  . . . . . . . . . . . . . . . . . . . .   3
     3.1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . .   3
     3.2.  Workflow and Functions  . . . . . . . . . . . . . . . . .   4
       3.2.1.  Rate Negotiation  . . . . . . . . . . . . . . . . . .   6
       3.2.2.  Admission Control . . . . . . . . . . . . . . . . . .   7
       3.2.3.  Traffic Scheduling and Enforcement  . . . . . . . . .   7
       3.2.4.  Optimization of Congestion Control Algorithms . . . .   7
       3.2.5.  Negotiated Rate-based Traffic Engineering . . . . . .   8
       3.2.6.  Fast Feedback . . . . . . . . . . . . . . . . . . . .   8
       3.2.7.  Flow Control  . . . . . . . . . . . . . . . . . . . .   8
   4.  Applicability of Host-network Collaboration Signalling  . . .   8
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   7.  Informative References  . . . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   Data-intensive applications always demand high-speed data
   transmission over WANs such as scientific research, academia,
   education as discussed in [I-D.kcrh-hpwan-state-of-art] and other
   applications in public networks as per
   [I-D.yx-hpwan-uc-requirements-public-operator].  The specific
   requirements of HP-WANs applications mainly focus on job-based
   massive data transmission over long-distance WANs, with set
   completion times.  High, reliable and effective data throughput is
   the fundamental requirement for HP-WAN.  It is crucial to achieve
   high throughput while ensuring the efficient use of capacity as per
   [I-D.xiong-hpwan-problem-statement].  Current technology does not
   guarantee these goals, and the issues may impact performance related
   to existing transport protocols and congestion control mechanisms
   such as poor convergence speed, long feedback loop, and unscheduled
   traffic.

   High-level requirements for HPWAN can be summarized as:






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   *Multiple data transfer requests should be scheduled in terms of
   available capacity and the requested completion time in terms of
   transmission performance;

   *From the routing aspect, the optimal path and resources should be
   scheduled based on the QoS policy for the high-speed flows to travel
   through the network with the negotiated data transfer rate;

   *From the transport aspect, it ensures the reliable delivery of data
   with traffic scheduling and admission control to effectively handle
   the flow of data during transmission, reducing congestion and
   ensuring timely delivery of data packets;

   *The host should consider signalling and collaborating with the
   network to negotiate the rates of differentiated traffic (especially
   when the traffic is encrypted) to avoid the congestion and optimize
   the overall efficiency of data transfer.

   This document defines a framework for these requirements, including
   the signaling goals to enable the host-and-network collaboration for
   the high-speed and high-throughput data transmission, coupled with
   fast completion time in High Performance Wide Area Network (HP-WAN).
   It particularly enhances the congestion control and facilitates the
   functionalities for the host to collaborate with the network to
   perform rate negotiation, such as QoS policy, admission control and
   traffic scheduling.

2.  Definition of Terms

   This document uses the terms defined in [I-D.kcrh-hpwan-state-of-art]
   and [I-D.xiong-hpwan-problem-statement]:

3.  Framework for HP-WAN

3.1.  Overview

   The framework is formulated to enable the host-network collaboration
   upon more active network involvement.  The client and server could
   adjust the rate efficiently and rapidly with the negotiated rate-
   based congestion control in a fine-grained way.  The network could
   enhance the capability to regulate the traffic and schedule the
   resources which could provide predictable network behaviour and
   mitigate incast network congestion preemptively.

   The following diagram illustrates the functionalities between Client/
   Server and WAN including:

   *Host-network collaboration signalling or protocol



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   *Active network-collaborated traffic enforcement and scheduling

   *Negotiated rate-based congestion control algorithms

                          +-------------------------------+
                          |             WAN               |
   +--------+             |                               |              +--------+
   |        |        +----+----+   +-------------+   +----+----+         |        |
   | Client |<------>|Edge Node|...|Transit Nodes|...|Edge Node|<------->| Server |
   |        |        +----+----+   +-------------+   +----+----+         |        |
   +--------+             |                               |              +--------+
       *collaboration     |                               |     *collaboration
      signalling/protocols|                               |     signalling/protocols
                          +-------------------------------+
  \_________/              \______________________________/
*Negotiated rate-based      *Active network-collaborated
congestion control            enforcement and scheduling
algorithms

                Figure 1 HP-WAN framework

3.2.  Workflow and Functions

   The following diagram illustrates the workflows among client, server
   and network nodes (e.g. edge nodes and transit nodes).

   *The request of scheduled traffic will be signalled from the client
   to the network based on the negotiated rate.  Furthermore, the
   traffic pattern and job-based requirements, such as completion time,
   should be included in the request.

   *The edge node will perform admission control and acknowledge the
   traffic, reserving the resource quota, but it will reject access when
   the network capacity cannot guarantee the job's completion time.

   *The acknowledgement will be signalled back from the network to the
   client, including the response with the negotiated rate and QoS
   policy for the client to send traffic.

   *The notification will be signalled from the client to the network to
   notify the completion of traffic, and the network will release the
   resource quota and cancel the acknowledgement of this job.

   *The update may signal to the client from the network to update the
   acknowledgement of the negotiated rate when new traffic requests are
   received.





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 +--------+               +-----------+       +------------+         +-----------+       +--------+
 | Client |               | Edge Node |       |Transit Node|         | Edge Node |       | Server |
 +----+---+               +-----+-----+       +-----+------+         +-----+-----+       +----+---+
      |                         |                   |                      |                  |
      |Requests(traffic pattern)|                   |                      |                  |
      |------------------------>|*Rate negotiation  |                      |    Requests      |
      |                         |*Traffic scheduling|                      |----------------->|
      |Acknowledgement          |*Admission control |                      | Acknowledgement  |
      |(negotiated rate)        |        *Reserve resource quota           |<-----------------|
      |<------------------------|*Negotiated rate-based traffic engineering|                  |
      |                         |<########################################>|                  |
      |New Request              |                   |                      |                  |
      |------------------------>|                   |                      |                  |
      |Update(negotiated rate)  |                   |                      |                  |
      |<------------------------|                   |                      |                  |
      |Notification(completion) |                   |                      | Notification     |
      |------------------------>|        *Release resource quota           |----------------->|
      |Acknowledgement(cancel)  |<########################################>| Acknowledgement  |
      |<------------------------|                   |                      |<-----------------|
      |                         |                   |                      |                  |
      V                         V                   V                      V                  V

                       Figure 2 The workflow of signalling between host and network

   The client could send traffic according to the negotiated rate policy
   to achieve a high throughput within the completion time.  And the
   edge node will send fast feedback with the advised rate when the
   traffic rate does not apply to the network.  It could also pause the
   traffic when congestion occurs (e.g. the traffic is exceeding the
   threshold of the server, the network performs the flow control).





















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 +--------+                 +-----------+   +------------+  +-----------+             +--------+
 | Client |                 | Edge Node |   |Transit Node|  | Edge Node |             | Server |
 +----+---+                 +-----+-----+   +-----+------+  +-----+-----+             +----+---+
      |                           |               |               |                        |
      |                           |               |               |                        |
      | Traffic(negotiated-rate)  |    Traffic(negotiated-rate)   |Traffic(negotiated-rate)|
      |-------------------------->|******************************>|----------------------->|
      |                           |               |               |   Exceeding threshold  |
      |                           |               |*Flow control  |<-----------------------|
      |                           |*Flow control  |<--------------|                        |
      | Fast Feedback(pause)      |<--------------|               |                        |
      |<--------------------------|               |               |                        |
      |  Traffic(wrong-rate)      |               |               |                        |
      |-------------------------->|               |               |                        |
      |Fast Feedback(advised-rate)|               |               |                        |
      |<--------------------------|               |               |                        |
      |                           |               |               |                        |
      V                           V               V               V                        V

                        Figure 3 The workflow of traffic between host and network

   The functions are described in the sections below including
   transport-related technologies such as rate negotiation, admission
   control, traffic scheduling and enforcement and routing-related
   technologies like traffic engineering, resource scheduling and load
   balancing.

3.2.1.  Rate Negotiation

   In HP-WAN, the host could negotiate the sending rate with the network
   due to the predictability of jobs.  The client communicates the
   traffic patterns of high-speed flows to the network to negotiate
   rate.  The traffic patterns may cover traffic information such as job
   ID, start time, completion time, data volume, traffic type and so on.
   The network responds to the negotiated rate and QoS policy for the
   client to send traffic.  There are three kinds of rate policy as
   follows:

   *Optimal rate or optimal rate range negotiation.  The network
   provides resource reservation for high-speed data to guarantee the
   transmission capacity and achieve optimal rate transmission.  The
   client could transmit flows according to the negotiated optimal rate
   or optimal rate range.

   *Minimum rate negotiation.  The network provides the minimum resource
   guarantee.  The client could transmit at a rate not less than the
   negotiated rate.




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   *Maximum rate negotiation.  The network provides an upper limit for
   resource guarantee.  The client could transmit at a rate not greater
   than the negotiated rate.

3.2.2.  Admission Control

   The network node should perform admission and traffic control based
   on negotiated QoS and rate.  By combining the admission control with
   congestion control, it can provide high throughput associated with
   completion time while efficiently using the available network
   capacity.  The strategies of admission control are different based on
   the QoS policy.  For example, one strategy is to immediately grant or
   reject admission to a reservation request on its arrival time, which
   is called on-demand admission control.  If a reservation request can
   not be granted or rejected at the time of its arrival, it will be put
   in a queue, which is called queue-based admission control.
   Furthermore, a time-slot based admission control is used for
   scheduling the elastic and flows requests.

3.2.3.  Traffic Scheduling and Enforcement

   The network node (e.g.edge node) performs rate-based traffic
   scheduling and enforcement.  For example, traffic classification may
   be needed based on the traffic type.  If it needs to prioritize
   critical traffic for acceleration, it should upgrade the priority of
   QoS.  Moreover, if the traffic needs a guaranteed QoS, it should
   provide guaranteed bandwidth for this flow.  It also could perform
   the aggregation of mouse flows or the fragmentation of an elephant
   flow if needed.  Splitting data across multiple paths for load
   balancing can increase the throughput and provide redundancy.  If one
   path experiences congestion, alternate paths compensate, ensuring
   timely delivery.  The traffic enforcement at network edges can used
   to regulate data flow to eliminate congestion and minimize the flow
   completion time.  For example, it could enforce the rate limits based
   on the negotiated rate to access traffic.

3.2.4.  Optimization of Congestion Control Algorithms

   The client should perform the improvement of congestion control
   algorithms based on the negotiated-rate from the network.  The
   negotiated-rate can be viewed as an initial congestion signal to
   assist the client in selecting a suitable sending rate with the
   network resource scheduling acknowledgement.  And it also needs to
   turn off and on or adjust the rate reasonably and rapidly when
   receiving the fast feedback from the node nearing the client.






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3.2.5.  Negotiated Rate-based Traffic Engineering

   The negotiated rate-based traffic engineering should be provided by
   routing technologies and the signaling from client will assist the
   network operator's traffic management and corresponding resource
   planning and scheduling.  The edge node may get information
   (topology, bottleneck link bandwidth, queue and buffer) from a
   centralized controller or through IGP advertisement.  The network
   should provide resource scheduling at nodes along the path and it is
   not bandwidth allocation but quota reservation which can be used for
   admission control.  The client and network can also negotiate rate
   based on the quota of each job.  Quota is expressed as a vector of
   resource quantities (bandwidth, buffer, queue, etc.) at a given
   priority, for a time frame.  The network can make dynamic bandwidth
   reservation upon different time frames defined by quota.  It will
   differ based on the different QoS policy.  For example, it is
   required to reserve the minimum bandwidth quota for the minimum rate
   policy.

3.2.6.  Fast Feedback

   The fast feedback function is optional for HP-WAN.  The edge node
   will send fast feedback with the advised rate when the traffic rate
   is not applicable to the network.  It could also pause traffic when
   congestion occurs and resume it when congestion is mitigated.

3.2.7.  Flow Control

   The specific elements along the path may be optional to provide
   active and precise flow control to mitigate network congestion to
   control the packet loss.  Flow control refers to a method for
   ensuring the data is transmitted efficiently and reliably and
   controlling the rate of data transmission to prevent the fast sender
   from overwhelming the slow receiver and prevent packet loss in
   congested situations.  For example, the receiver node could signal
   the sender node to control the traffic on or off to guarantee the
   packet loss.  When the data sent by the client exceeds the threshold,
   the network should provide fast and accurate quantitative feedback to
   control the traffic on or off.

4.  Applicability of Host-network Collaboration Signalling

   There are several existing signalling options for HP-WAN host-network
   collaboration signalling such as RSVP and GRASP.  There will be two
   deployment scenarios in HP-WAN.  The first one will be the central
   controller deployment which will have a hierarchical planning and
   resource reservation in the network like CERN deployment and the
   SENSE architecture.  In this case, the host-newtork signalling



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   (between client and edge node) may be peer-to-peer solution and both
   GRASP and RSVP may be applicable.  And the second case will be
   distributed or hybrid deployment in the network which needs
   distributed signalling along the path for resource reservation.  In
   this case, the host may signal from the client to the network nodes
   along the path.  RSVP may be applicable but not GRASP.

   GRASP is peer-to-peer signalling and is designed for synchronization
   and negotiation between autonomic service agents, which reduces the
   need for hierarchy and allows the intelligence to be distributed
   rather than centralized.  However it is not applicable when the
   signalling should be performed along the end-to-end path.

   Although RSVP may not be deployable with complex configuration and
   management which requires precise configuration across all network
   devices along the path.  It will also add administrative complexity
   between host and network in HP-WAN with operational issues.  But SR,
   slicing, diffServ QoS and SDN-based approaches may be used to largely
   improve RSVP in HP-WAN.  Moreover, RSVP reservations often allocate
   fixed resources in the nodes along the path, which can lead to
   underutilization if the reserved resources are not fully used.  The
   extensions may be required to applied to HP-WAN that the bandwidth
   and rate vary over time and it requires scalable throughput, dynamic
   bandwidth reservation and efficient use of capacity.

5.  Security Considerations

   To be discussed in future versions of this document.

6.  IANA Considerations

   Currently this document does not make an IANA requests.

7.  Informative References

   [I-D.kcrh-hpwan-state-of-art]
              King, D., Chown, T., Rapier, C., and D. Huang, "Current
              State of the Art for High Performance Wide Area Networks",
              Work in Progress, Internet-Draft, draft-kcrh-hpwan-state-
              of-art-01, 8 January 2025,
              <https://datatracker.ietf.org/doc/html/draft-kcrh-hpwan-
              state-of-art-01>.









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   [I-D.xiong-hpwan-problem-statement]
              Xiong, Q., Yao, K., Huang, C., Zhengxin, H., and J. Zhao,
              "Problem Statement for High Performance Wide Area
              Networks", Work in Progress, Internet-Draft, draft-xiong-
              hpwan-problem-statement-02, 25 February 2025,
              <https://datatracker.ietf.org/doc/html/draft-xiong-hpwan-
              problem-statement-02>.

   [I-D.yx-hpwan-uc-requirements-public-operator]
              Yao, K. and Q. Xiong, "High Performance Wide Area Network
              (HPWAN) Use Cases and Requirements -- From Public
              Operator's View", Work in Progress, Internet-Draft, draft-
              yx-hpwan-uc-requirements-public-operator-00, 20 February
              2025, <https://datatracker.ietf.org/doc/html/draft-yx-
              hpwan-uc-requirements-public-operator-00>.

Authors' Addresses

   Quan Xiong
   ZTE Corporation
   Email: xiong.quan@zte.com.cn


   Guangping Huang
   ZTE Corporation
   Email: huang.guangping@zte.com.cn


   Kehan Yao
   China Mobile
   Email: yaokehan@chinamobile.com


   Changwang Lin
   New H3C Technologies
   Email: linchangwang.04414@h3c.com















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