Network Working Group                                              Z. Du
Internet-Draft                                                    P. Liu
Intended status: Standards Track                                 L. Geng
Expires: January 14, 2021                                   China Mobile
                                                           July 13, 2020


    Path Information Detection in Application-aware IPv6 Networking
               draft-du-apn6-path-infomation-detection-00

Abstract

   This document introduces a method to detect path 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
   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 January 14, 2021.

Copyright Notice

   Copyright (c) 2020 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



Du, et al.              Expires January 14, 2021                [Page 1]


Internet-Draft     Path Information Detection in APN6          July 2020


   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Current Mechanism in APN6 . . . . . . . . . . . . . . . . . .   2
   3.  Path Latency Information Detection  . . . . . . . . . . . . .   3
   4.  Other Path Information Detection  . . . . . . . . . . . . . .   4
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   5
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   5

1.  Introduction

   Application-aware IPv6 Networking is a kind of self-identified
   mechanism per packet.  In the mechanism of APN6
   [I-D.li-apn6-problem-statement-usecases], an IPv6 packet can carry
   the APP ID information and SLA requirements of the traffic in its
   Extension Headers.  Therefore, the network equipment can analyze them
   in each packet and handle the packet accordingly.

   This novel mechanism can enable the negotiation between the user
   traffic and the network.  The network can supply proper treatment for
   different kinds of user traffic.  As a result of this flexible on-
   demand SLA mechanism, the user can get a better experience, and the
   network resource can be scheduled more efficiently.

   However, the current mechanism in APN6 only enables a unidirectional
   information notification, i.e., from the APP/user to the network.
   The APP/user is not aware of the path information in the network.  In
   some cases, it is not sufficient.  A bidirectional information
   negotiation mechanism can enable a more powerful APN6 platform.

   This document introduces the process of the path information
   detection mechanism in APN6 by extending some IPv6 Extension Headers.

2.  Current Mechanism in APN6

   As shown in Figure 1, the APN framework [I-D.li-apn-framework]
   includes App (Client and Server), App-aware Edge, App-aware-process




Du, et al.              Expires January 14, 2021                [Page 2]


Internet-Draft     Path Information Detection in APN6          July 2020


   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.  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.  The former is recorded in
   the Application-aware ID Options, and the latter is recorded in the
   Service-Para Options defined in the [I-D.li-apn-framework].

   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
   policies, 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.

3.  Path Latency Information Detection

   In the APN architecture, the user/APP can give a latency requirement
   to the network, and the network will provide a low latency path for
   the traffic.  The path may be the one with the lowest latency among
   the set of paths between the Head-End and the End-Point, or may be
   one of the paths with a lower latency than the value carried in the
   latency requirement TLV.  However, the users/APPs do not know how
   well the network handle the requirements, especially when the APPs
   give multiple requirements.

   An APP can easily obtain a bidirectional E2E latency, i.e., the sum
   of the bidirectional network latency and the server latency, but it



Du, et al.              Expires January 14, 2021                [Page 3]


Internet-Draft     Path Information Detection in APN6          July 2020


   does not know the exact network latency.  The mechanism proposed in
   this document can provide this information to the APP, and the APP
   can confirm the network's SLA guarantee activity if needed.

   In details, the APP can add a new Service-Para Option named Timestamp
   Request TLV into the packet to indicate that it needs the timestamps
   of the headend and the endpoint in the network.  The headend and the
   endpoint can read the TLV and add two new Timestamp TLVs in the IPv6
   extension header, which contain the time that the packet reach the
   headend and the endpoint respectively.  Then, the server can receive
   this specific packet with the Timestamp Request TLV and the two
   Timestamp TLVs.  The server can record the timestamps, and
   encapsulate them into a packet that is about to be sent to the APP.
   This packet can also include a Timestamp Request TLV.  On the
   converse direction, the headend and the endpoint in the network can
   add another two Timestamp TLVs into the packet.  Hence, the APP can
   get four timestamps in total, and know the forwarding path latency
   and the reverse path latency of the network.

4.  Other Path Information Detection

   The APP can also request other information by extending more Request
   TLVs and Information TLVs in the IPv6 extension header.  For example,
   the APP can request to obtain the SR policy BSID in the Path
   Information TLV.  In this case, only the headend on the forwarding
   direction needs to add information into the packet.  As the
   information needs to be handled by the server, the BSID can be stored
   in DOH (Destination Options Header) of the packet.

   When the APP has obtained the BSID, it can add it into the SID list
   contained in the packet or into a new Service-Para Option.  The
   headend can directly steer the traffic to a specific SR Policy
   according to that information.  Therefore, it only needs to analyze
   the several packets in the traffic at the beginning, and does not
   need to analyze the following packets with BSID in the traffic in
   details.

5.  IANA Considerations

   TBD.

6.  Security Considerations

   TBD.







Du, et al.              Expires January 14, 2021                [Page 4]


Internet-Draft     Path Information Detection in APN6          July 2020


7.  Acknowledgements

   TBD.

8.  References

8.1.  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>.

8.2.  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





Du, et al.              Expires January 14, 2021                [Page 5]


Internet-Draft     Path Information Detection in APN6          July 2020


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

   Email: gengliang@chinamobile.com












































Du, et al.              Expires January 14, 2021                [Page 6]