Network Working Group                                              Z. Du
Internet-Draft                                                    P. Liu
Intended status: Standards Track                                 L. Geng
Expires: September 10, 2020                                 China Mobile
                                                           March 9, 2020


          Auto-adjustment of Encapsulation Information in APN6
             draft-du-apn6-auto-encapsulation-adjustment-00

Abstract

   This document introduces a method to adjust the encapsulation
   information in Application-aware IPv6 Networking.

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
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   This Internet-Draft will expire on September 10, 2020.

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   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   carefully, as they describe your rights and restrictions with respect



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   to this document.  Code Components extracted from this document must
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Auto-adjustment of Encapsulation Information  . . . . . . . .   3
     2.1.  Current Mechanism in APN6 . . . . . . . . . . . . . . . .   3
     2.2.  Comparisons of Data Plane and Control Plane Programming .   3
     2.3.  Potential Solutions for Auto-adjustment . . . . . . . . .   4
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   5
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   As the development of 5G and new emerging Internet services, such as
   live video streaming, the network are facing a larger and larger SLA
   difference between two different kinds of traffic.  For better
   bearing of the user's traffic, the network needs to be intelligent
   and be aware of the user traffic's demand.  An innovation method
   called APN6 is introduced in [I-D.li-apn6-problem-statement-usecases]
   and [I-D.li-apn-framework].

   In the mechanism of APN6, the packet can carry the ID information and
   SLA requirements of the traffic, and the network equipment can get
   them in each packet and handle the packet accordingly.  It is one
   kind of network programming mechanisms in the data plane.

   As encapsulation information increases in an APN packet, some
   bandwidth is kindly wasted in APN6 which uses a larger overhead in
   every packet.  On one aspect, it is believed that it is necessary for
   the evolution to the intelligent network; on the other aspect, it is
   recommended that after the network has known the requirements of the
   traffic and associated it with a proper policy, the traffic needs not
   to resend the same information in every packet again and again.  This
   document mainly talks about the process of the later.








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2.  Auto-adjustment of Encapsulation Information

2.1.  Current Mechanism in APN6

   As shown in Figure 1, the APN framework [I-D.li-apn-framework]
   includes Service-aware App, App-aware Edge Device, App-aware-process
   Head-End, App-aware-process Mid-Point, and App-aware-process End-
   Point.

  Client                                                         Server
  +-----+                                                        +-----+
  |App x|-\                                                   /->|App x|
  +-----+ |   +-----+ +---------+   +---------+   +---------+ |  +-----+
           \->|App- | |App-aware|-A-|App-aware|-A-|App-aware|-/
  User side   |aware|-|process  |-B-|process  |-B-|process  |
           /->|Edge | |Head-End |-C-|Mid-Point|-C-|End-Point|-\
  +-----+ |   +-----+ +---------+   +---------+   +---------+ |  +-----+
  |App y|-/                                                   \->|App y|
  +-----+           ---------  Uplink   ---------->              +-----+

               Figure 1: Framework and Key Components in APN6


   The data-driven process of APN6 is described below.

   The APP or the APP-aware Edge will generate an APN packet which
   carries the application characteristic information in the
   encapsulation.

   App-aware-process Head-End can read that information and steer the
   packet into a given policy which satisfies the application
   requirements.  It is supposed that a set of paths, tunnels or SR
   policy, exist between the App-aware-process Head-End and the App-
   aware-process End-Point.  App-aware-process Head-End can find one
   existing path or establish a new one for the traffic.

2.2.  Comparisons of Data Plane and Control Plane Programming

   We can realize the same traffic steering in the control plane.  The
   control-plane based process, which is described below, includes three
   key components: the identity of the traffic, policies in Head-End,
   and the interface to notify the user requirements.

   The APP or the Edge knowing the application characteristic
   information, needs to report that information to the controller of
   the Head-End by some means.





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   The controller needs to know the traffic requirements and the status
   of the network, and generate a policy for the Head-End. The policy
   SHOULD include the identity of the traffic and the path that the
   traffic should follow.

   The Head-End needs to implement the policy, and steer the traffic to
   the proper path.

   In this mechanism, we do not need to carry extra information in each
   packet, but need to generate control messages between the Edge and
   the controller, and between the Head-End and the controller.

   If the traffic is not that large, and simple to handle, a control-
   layer decision-loop is not that necessary.  By comparison, a date-
   driven method is more flexible.  Of course, the Head-End after
   steering the traffic needs to report the (summarized) change to the
   controller.

2.3.  Potential Solutions for Auto-adjustment

   We can find that after the Head-End has enabled the policy, the extra
   information carried in the following APN6 packets has little use.
   Therefore, an auto-adjustment of encapsulation information mechanism
   may be helpful for the simplification of the following APN6 packets.

   According to [I-D.li-apn-framework], the information may include
   application-aware identification, such as SLA level, application ID,
   user ID, flow ID, etc., and network performance requirements, such as
   bandwidth, latency, jitter, packet loss ratio, etc.  Hence, at least,
   we can send only the application-aware identification information in
   the following APN6 packets without network performance requirements
   information.

   Two methods are talked about below.

   One straightforward method is that we firstly send full information
   in APN6 packets, and after 3 seconds, we send APN6 packets that only
   contains the necessary information, such as the application-aware
   identification information.  In this method, we believe that the
   Head-End can handle the policy mapping in 3 seconds.  Of courses, the
   "3 seconds" is just an example here, which can be adjusted according
   to the situation of each network.

   Another method is that after enabling the policy, the Head-End needs
   to notify the encapsulation point by some means.  However, we do not
   have a notification mechanism between different nodes in the data-
   plane network programming now.  We need to notify by using the




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   control plane again.  The control plane sends a message to the
   encapsulation point to adjust the encapsulation degree.

   This document suggests to enable a simple notification method for the
   data-plane network programming if the information is not that
   complicated.  For example, we can send a "ping" message with a
   specific flag to the encapsulation point.  The advantage is easy to
   inter operate.

   In future, with the technical development of network equipments, the
   bandwidth may not be the bottle neck anymore, so that a full APN6
   encapsulation packet may be used widely to enable the data plane
   intelligence.  However, the auto-adjustment of encapsulation
   information method can help the adoption of the APN6 mechanism by
   providing a transit solution.  Meanwhile, this document also provides
   a feedback mechanism for the data plane programming to enable the
   coordination between different nodes.

   .

3.  IANA Considerations

   TBD.

4.  Security Considerations

   TBD.

5.  Acknowledgements

   TBD.

6.  References

6.1.  Normative References

   [I-D.li-apn-framework]
              Li, Z., Peng, S., Voyer, D., Li, C., Geng, L., Cao, C.,
              Ebisawa, K., Previdi, S., and J. Guichard, "Application-
              aware Networking (APN) Framework", draft-li-apn-
              framework-00 (work in progress), March 2020.

   [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>.





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6.2.  Informative References

   [I-D.li-apn6-problem-statement-usecases]
              Li, Z., Peng, S., Voyer, D., Xie, C., Liu, P., Liu, C.,
              Ebisawa, K., Previdi, S., and J. Guichard, "Problem
              Statement and Use Cases of Application-aware IPv6
              Networking (APN6)", draft-li-apn6-problem-statement-
              usecases-01 (work in progress), November 2019.

Authors' Addresses

   Zongpeng Du
   China Mobile
   No.32 XuanWuMen West Street
   Beijing  100053
   China

   Email: duzongpeng@foxmail.com


   Peng Liu
   China Mobile
   No.32 XuanWuMen West Street
   Beijing  100053
   China

   Email: liupengyjy@chinamobile.com


   Liang Geng
   China Mobile
   No.32 XuanWuMen West Street
   Beijing  100053
   China

   Email: gengliang@chinamobile.com















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