Network Working Group                                            F. Yang
Internet-Draft                                                  W. Cheng
Intended status: Informational                              China Mobile
Expires: 5 September 2022                                        S. Peng
                                                                   Z. Li
                                                                  Huawei
                                                            4 March 2022


    Usage scenarios of Application-aware Networking (APN) for SD-WAN
                    draft-yang-apn-sd-wan-usecase-04

Abstract

   This document describes the usage of Application-aware Networking
   (APN) in SD-WAN scenarios.  In these scenarios, APN is able to
   identify a application group, steer its traffic flows along explicit
   path across the network, and provide SLA guaranteed network services
   such as low latency and high reliability.

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 5 September 2022.

Copyright Notice

   Copyright (c) 2022 IETF Trust and the persons identified as the
   document authors.  All rights reserved.




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   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
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   extracted from this document must include Revised BSD License text as
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   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Usage Scenarios of APN for SD-WAN . . . . . . . . . . . . . .   3
     2.1.  APN for Traffic Steering into Dedicated WAN . . . . . . .   3
     2.2.  APN for Traffic Steering into Particular Cloud  . . . . .   3
     2.3.  APN for Value-added Service Provisioning in SD-WAN  . . .   4
     2.4.  APN for Data Processing in SD-WAN . . . . . . . . . . . .   4
   3.  APN with SRv6 . . . . . . . . . . . . . . . . . . . . . . . .   5
   4.  APN with In-Flow OAM  . . . . . . . . . . . . . . . . . . . .   5
   5.  APN with Intention based Policy . . . . . . . . . . . . . . .   5
   6.  Business Model of APN enhanced SD-WAN . . . . . . . . . . . .   6
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   9.  Normative References  . . . . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   As more and more applications are moved to the cloud, the traditional
   WAN architecture starts facing challenges.  Software-defined Wide
   Area Network (SD-WAN) provides a cloud-friendly way of
   interconnecting branch offices and applications in the cloud over any
   combination of transport services such as MPLS and 4G LTE, which is
   able to optimising application performance with low costs.

   Application-aware Networking (APN) is introduced in
   [I-D.li-apn-framework] and [I-D.li-apn-problem-statement-usecases].
   APN conveys application-aware information (i.e.  APN attribute) along
   data packets traversing across the APN domain and facilitate fine-
   granularity network service provisioning and guarantee their SLA
   requirements.  The ever-emerging network services such as network
   slicing and IOAM can be further enhanced with APN.

   This document describes the usage scenarios of APN for SD-WAN.







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2.  Usage Scenarios of APN for SD-WAN

   This section describes the scenarios that can use APN to meet the
   fine-granularity service operations in SD-WAN.

2.1.  APN for Traffic Steering into Dedicated WAN

   In CPE, different application groups are identified based on the
   existing information in the packet header, and APN attribute is added
   to the packets along with the tunnel encapsulation.  Then the traffic
   flows can be steered into different WANs that can guarantee their
   corresponding SLA requirements.

+------+                        +-----------+                     +------+
| APP1 |                 /------|    WAN1   |------\              | APP1 |
+------+                /       +-----------+       \             +------+
  +------+     +-------+      +-----------+      +--------+     +------+
  | APP2 |-----|  CPE  |------|    WAN2   |------|  CPE   |-----| APP2 |
  +------+     +-------+      +-----------+      +--------+     +------+
+------+                \       +-----------+       /             +------+
| APP3 |                 \------|    WAN3   |------/              | APP3 |
+------+                        +-----------+                     +------+

                 Figure 1: Traffic Steering into WAN

2.2.  APN for Traffic Steering into Particular Cloud

   In the multi-cloud scenario, a CPE can be deployed by an enterprise
   as its gateway to access different clouds.  In the CPE (e.g. an
   universial CPE, called uCPE), different application groups can be
   identified based on the existing information in the packet header,
   and APN attribute is added to the packets along with the tunnel
   encapsulation.  The traffic flows are steered into the corresponding
   cloud where the application servers are running through the
   corresponding WANs.

   +------+                       +-----------+     +----------+
   | APP1 |             /---------|    WAN1   |-----|  Cloud1  |
   +------+            /          +-----------+     +----------+
     +------+     +--------+     +-----------+     +----------+
     | APP2 |-----|   CPE  |-----|    WAN2   |-----|  Cloud2  |
     +------+     +--------+     +-----------+     +----------+
   +------+            \          +-----------+     +----------+
   | APP3 |             \---------|    WAN3   |-----|  Cloud3  |
   +------+                       +-----------+     +----------+

                   Figure 2: Traffic Steering into Cloud




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2.3.  APN for Value-added Service Provisioning in SD-WAN

   APN can faciliate the value-added service provisioning in SD-WAN,
   either at the CPE or the POP.

   At the CPE, network security and application acceleration services
   can be provided.  With APN, certain malicious traffic can be
   identified and blocked, while the traffic that requires acceleration
   can be steered through the acceleration service.

   At the POP, value-added service can be provisioned for certain
   application groups according to the APN attribute carried in their
   packets.

                                +------------+
                                |POP(VAS/SFC)|
                                +------------+
                                       |
  +-----+    +------------+     +------------+     +------------+     +-----+
  | APP |----|CPE(VAS/SFC)|-----|     WAN    |-----|CPE(VAS/SFC)|-----| APP |
  +-----+    +------------+     +------------+     +------------+     +-----+

                      Figure 3: VAS Provisioning

2.4.  APN for Data Processing in SD-WAN

   In enterprise, usually important data is kept locally and it is
   preferred to be processed locally, while other data can be processed
   with the complex processing capabilities in the cloud.

   With APN, the traffic can be steered according to the localization
   characteristics of the data, either being processed locally or in the
   cloud.

     +------+     +-------+     +------------+     +------------------+
     | Data |-----|  CPE  |-----|    WAN     |-----| Cloud (Computing)|
     +------+     +-------+     +------------+     +------------------+
                       \
                        \    +---------------------------+
                         --- | Local DC (Data Processing)|
                             +---------------------------+

                         Figure 4: Data Processing








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3.  APN with SRv6

   By carrying the APN attribute (including APN ID and APN parameters)
   through data packets, i.e., the delivery of application-aware
   information and ensuring the security and reliability of application-
   aware information, the network senses the application groups'
   requirements and provides high-quality differentiated services
   according to the demand of the applications.  And when the network
   transmits the data packets, it matches the network correspondence
   policy according to the APN attribute in the data packets and selects
   the corresponding SRv6 path to transmit the data packets (e.g., low
   latency path) to meet the SLA requirements and service chain in order
   to improve the service quality.

      +------+                 +-----------+                   +------+
      | APP1 |           /-----| SRv6 path1|-----\             | APP1 |
      +------+          /      +-----------+      \            +------+
        +------+   +-------+    +-----------+   +--------+   +------+
        | APP2 |---|  CPE  |----| SRv6 path2|---|  CPE   |---| APP2 |
        +------+   +-------+    +-----------+   +--------+   +------+
      +------+          \      +-----------+      /            +------+
      | APP3 |           \-----| SRv6 path3|-----/             | APP3 |
      +------+                 +-----------+                   +------+

                       Figure 5: SRv6 enabled SD-WAN

4.  APN with In-Flow OAM

   SD-WAN needs to guarantee the experience of critical applications,
   and APNs can be used to carry application information to
   differentiate between different application traffic.  At the same
   time, it is necessary to conduct end-to-end application-level network
   quality awareness to achieve closed-loop control of network quality.
   SD-WAN uses Overlay to establish connectivity, which enable flow
   classification with APN, and work with In-Flow OAM detection to
   identify critical applications from thousands of streams, thus
   simplifying network quality assurance technology complexity for
   critical applications.

5.  APN with Intention based Policy

   By using APNs to identify services, SD-WAN can relate global policies
   to user service.  This allows SD-WAN to automatically enforce
   performance goals and access security for users, regardless of their
   location.  By identifying and sensing the service type, the global
   policy automatically selects a path for the service, such as
   Internet, to offload bandwidth-hungry services to the lower-cost
   Internet.  Based on the global policy, rather than the network



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   architecture, decisions can be made on how to isolate between
   endpoints, applications, and the cloud.  Global policies also can be
   visualized and changed in real time to achieve sustainable trust as
   the network evolves.

6.  Business Model of APN enhanced SD-WAN

   With the digital transformation, the network infrastructure and
   cloud-based applications are emerging as an integrated service of
   network operators to provide a complete solution to customer.  As an
   overlay technology, SD-WAN is able to simplify the network and make
   it more service-focused, which has become the de facto option for the
   Enterprise WAN Edge.  SD-WAN enables the network service providers to
   reshape their network to provide more complex products to meet
   customers' various requirements.

   When SD-WAN is integrated with APN, service providers are able to
   provide network services together with cloud services in a fine-
   granularity SaaS-like model.  The latest functionalities can be
   delivered via cloud.  Customers benefit from the pay-for-use model in
   per application granularity and have the agility to adjust the level
   of functionality, capability, and capacity.  According to the APN
   attribute carried by the packets, corresponding paths/WANs can be
   selected, the SLA can be guaranteed, and value-added services can be
   provisioned.

7.  Security Considerations

   The security consideration can refer to [I-D.li-apn-framework] .

8.  IANA Considerations

   There are no IANA considerations in this document.

9.  Normative References

   [I-D.li-6man-app-aware-ipv6-network]
              Li, Z., Peng, S., Li, C., Xie, C., Voyer, D., Li, X., Liu,
              P., Cao, C., and K. Ebisawa, "Application-aware IPv6
              Networking (APN6) Encapsulation", Work in Progress,
              Internet-Draft, draft-li-6man-app-aware-ipv6-network-03,
              22 February 2021, <https://www.ietf.org/archive/id/draft-
              li-6man-app-aware-ipv6-network-03.txt>.

   [I-D.li-apn-framework]
              Li, Z., Peng, S., Voyer, D., Li, C., Liu, P., Cao, C.,
              Mishra, G., Ebisawa, K., Previdi, S., and J. N. Guichard,
              "Application-aware Networking (APN) Framework", Work in



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              Progress, Internet-Draft, draft-li-apn-framework-04, 25
              October 2021, <https://www.ietf.org/archive/id/draft-li-
              apn-framework-04.txt>.

   [I-D.li-apn-problem-statement-usecases]
              Li, Z., Peng, S., Voyer, D., Xie, C., Liu, P., Qin, Z.,
              Mishra, G., Ebisawa, K., Previdi, S., and J. N. Guichard,
              "Problem Statement and Use Cases of Application-aware
              Networking (APN)", Work in Progress, Internet-Draft,
              draft-li-apn-problem-statement-usecases-05, 20 December
              2021, <https://www.ietf.org/archive/id/draft-li-apn-
              problem-statement-usecases-05.txt>.

   [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>.

Authors' Addresses

   Feng Yang
   China Mobile
   Beijing
   China
   Email: yangfeng@chinamobile.com


   Weiqiang Cheng
   China Mobile
   Beijing
   China
   Email: chengweiqiang@chinamobile.com


   Shuping Peng
   Huawei
   Beijing
   China
   Email: pengshuping@huawei.com


   Zhenbin Li
   Huawei
   Beijing
   China
   Email: lizhenbin@huawei.com





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