Skip to main content

AAA for Hierarchical Network Slices
draft-zhang-rtgwg-aaa-hierarchical-network-slices-00

Document Type Active Internet-Draft (individual)
Authors Xiaoqiu Zhang , Changwang Lin , Yuanxiang Qiu
Last updated 2024-01-07
RFC stream (None)
Intended RFC status (None)
Formats
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date (None)
Responsible AD (None)
Send notices to (None)
draft-zhang-rtgwg-aaa-hierarchical-network-slices-00
RTGWG                                                          X. Zhang
Internet-Draft                                             China Mobile
Intended status: Standards Track                                 C. Lin
Expires: July 8, 2024                                            Y. Qiu
                                                   New H3C Technologies
                                                        January 8, 2024

                    AAA for Hierarchical Network Slices
            draft-zhang-rtgwg-aaa-hierarchical-network-slices-00

Abstract

   This document describes an enhanced AAA mechanism for hierarchical
   network slice service when users access to the network and use the
   network slice resources of different SLA levels.

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), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   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."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html

   This Internet-Draft will expire on July 6, 2024.

Copyright Notice

   Copyright (c) 2024 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
   (http://trustee.ietf.org/license-info) in effect on the date of

Zhang, et al.            Expires July, 2024                   [Page 1]
Internet-Draft   AAA for Hierarchical Network Slices       January 2024

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

Table of Contents

   1. Introduction ................................................ 2
      1.1. Requirements Language .................................. 4
      1.2. Terminology ............................................ 4
   2. Gap analysis for current AAA mechanism ...................... 4
   3. AAA Method for hierarchical IETF network slices ............. 4
   4. IANA Considerations ......................................... 6
   5. Security Considerations ..................................... 6
   6. References .................................................. 7
      6.1. Normative References ................................... 7
      6.2. Informative References ................................. 7
   7. Acknowledgments ............................................. 8
   Authors' Addresses ............................................. 9

  1. Introduction

   Network slicing provides the ability to partition a physical network
   into multiple isolated logical networks of varying sizes,
   structures, and functions so that each slice can be dedicated to
   specific services or customers. Hierarchical composition of IETF
   Network Slice means that a network slice can be further sliced into
   other network slices, as shown in Figure 1.

Zhang, et al.            Expires July, 2024                   [Page 2]
Internet-Draft   AAA for Hierarchical Network Slices       January 2024

                        +-------------------+
                        |      Underlay     |
                        |      Network      |
                        +---------+---------+
                                  |
                    +-------------+-------------+
                    |                           |
                    V                           V
              +-----------+               +-----------+
              |  Level-1  |               |  Level-1  |
              |  Network  |               |  Network  |
              |   Slice   |               |   Slice   |
              |     1     |               |     2     |
              +-----+-----+               +-----+-----+
                    |                           |
             +------+------+             +------+------+
             |             |             |             |
             V             V             V             V
        +---------+   +---------+   +---------+   +---------+
        | Level-2 |   | Level-2 |   | Level-2 |   | Level-2 |
        | Network |   | Network |   | Network |   | Network |
        |  Slice  |   |  Slice  |   |  Slice  |   |  Slice  |
        |   1-1   |   |   1-2   |   |   2-1   |   |   2-2   |
        +---------+   +---------+   +---------+   +---------+
        Figure 1: Architecture of Two-level Hierarchical IETF Network
        Slices

   [I-D.dong-teas-hierarchical-ietf-network-slice] describes several
   possible scenarios of hierarchical IETF network slices. For example,
   Level-1 can be industry slices which are used to deliver services
   for different vertical industries, and Level-2 can be customer
   slices which are created to meet specific requirements of some or
   all of the customers within the corresponding industry of level-1.
   [I-D.draft-gong-teas-hierarchical-slice-solution] describes a
   Segment Routing based solution for two-level hierarchical IETF
   network slices. Level-1 network slice is realized by associating
   Flex-Algo with dedicated sub-interfaces, and level-2 network slice
   is realized by using SR Policy with additional NRP-ID on data plane.
   [I-D.draft-cheng-spring-sr-policy-group] describes another Segment
   Routing based solution for two-level hierarchical network slices.
   Level-1 network slice is realized by SR policy group which is a
   group of constituent Parent SR policies to different destination
   endpoints with the same service forwarding model, and level-2
   network slice is realized by SR policy or Parent SR policy which can
   provide paths for different SLAs.

Zhang, et al.            Expires July, 2024                   [Page 3]
Internet-Draft   AAA for Hierarchical Network Slices       January 2024

   As the above solutions for hierarchical network slices have been
   proposed and the current AAA mechanism cannot meet this new
   requirements, this document describes an enhanced AAA mechanism for
   hierarchical network slice service when users access to the network
   and use the network slice resources of different SLA levels.
1.1. Requirements Language

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

1.2. Terminology

   The terms in this document are defined in [RFC8402], [I-D.ietf-teas-
   ietf-network-slices] and [I-D.ietf-lsr-flex-algo].

    The following lists widely used terms in this document.

   AAA: Authentication, Authorization and Accounting

   FA: Flexible Algorithm

   NRP: Network Resource Partition

  2. Gap analysis for current AAA mechanism

   In traditional network architecture, network nodes such as BRAS
   devices and AAA servers which provide AAA abilities especially
   accounting only need to concern the consumption of network
   resources, such as access time, bandwidth, etc. For the new business
   scenarios of hierarchical IETF network slices the current AAA
   mechanism need to recognize the levels of network slice and related
   information, which can achieve the fine-grained management of
   authentication authorization and accounting and meet the diverse
   and multi-quantity business requirements of cloud-network
   convergence.

   To address this issue, this document proposes an enhanced AAA method
   for hierarchical IETF network slices.

  3. AAA Method for hierarchical IETF network slices

   The following figure shows a typical architecture of AAA process
   based on hierarchical IETF network slice service. There are three

Zhang, et al.            Expires July, 2024                   [Page 4]
Internet-Draft   AAA for Hierarchical Network Slices       January 2024

   roles here, including user device, network device such as BRAS and
   AAA server such as Radius server.

      user device
      +------+
      |  A   |----+
      +------+    |
                  |
      user device |     +-------------------+        +-------------------+
      +------+    +---->|                   |<-------|                   |
      |  B   |--------->|   Network device  |        |    AAA server     |
      +------+    +---->|                   |------->|                   |
                  |     +-------------------+        +-------------------+
      user device |
      +------+    |
      |  C   |----+
      +------+

             Figure 1: AAA Process for hierarchical network slices

   This document proposes an enhanced AAA method for hierarchical IETF
   network slices. All the processes below are describes as an example
   of two-level network slices.

3.1. The authentication and authorization process for network slices

   1. When user device accesses to the network, it sends the request
      message for authentication which includes username password, user
      characteristics and service information.

   2. The network device receives the authentication request message
      carrying the information of username password, user
      characteristics and service from user device, and sends it to the
      AAA server.

   3. The AAA server receives the request and completes the
      authentication process. Based on the user's characteristics and
      service information in the request message, it selects an
      appropriate network slicing strategy for the user, encapsulates it
      in the user authorization message, and sends it to the network
      device.

      The network device allows users to be online and consume the
      corresponding slice resources based on the authorization
      information.

Zhang, et al.            Expires July, 2024                   [Page 5]
Internet-Draft   AAA for Hierarchical Network Slices       January 2024

      The first level slice is divided based on the first object, which
      can be SRv6 policy group or SR FlexAlgo (FA for short) protocol
      with dedicated sub-interfaces. The second level slice is divided
      based on the second object on the basis of the first level slice,
      which can SR Policy with additional NRP-ID/Slice-ID on data plane.
      The information mainly is the two-level slice identification (id
      for short), the first level slice id can use the id introduced by
      the control plane technology such as FA-id, the second level slice
      id can use the id introduced by the data plane technology such as
      NRP-ID.

   4. When the users access online, the AAA server starts accounting for
      the users within the slice.

3.2. The accounting process for network slices

   1. The network device sends an accounting start request message,
      which at least includes information about the network slice
      currently used by the user, that is, the first and second level
      slices.

      The information of two-level slices mainly is as follows: The
      first level slice id could be FA-id as an example, the second
      level slice id could be NRP-ID as an example.

   2. If the request is legal, the accounting servers would record the
      users and corresponding two-level slices information in the
      database and returns a reply message to the network device.

   3. When the user logs out, the server would receive a request message
      for accounting stop which includes the information of two-level
      network slices, time, and reason for stopping accounting. Then the
      server can record the users and corresponding two-level slices
      information for stopping accounting in the database.

   We consider to add the information of two-level slices such as FA-id
   and NRP-ID in the accounting messages by extending the Attribute
   field of Radius protocol message.

  4. IANA Considerations

   TBD

  5. Security Considerations

   The potential security threats of Alternate-Marking method have been
   described in detail in Section 10 of [I-D.draft-ietf-ippm-

Zhang, et al.            Expires July, 2024                   [Page 6]
Internet-Draft   AAA for Hierarchical Network Slices       January 2024

   rfc8321bis]. The performance measurement method described in this
   document does not introduce additional new security issues.

6. References

6.1. 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>.

   [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>.

   [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>.

   [I-D.ietf-teas-ietf-network-slices] Farrel, A., Drake, J., Rokui,
             R., Homma, S., Makhijani, K., Contreras, L. M., and J.
             Tantsura, "Framework for IETF Network Slices", Work in
             Progress, Internet-Draft, draft-ietf-teas-ietf-network-
             slices-12, 30 June 2022,
             <https://www.ietf.org/archive/id/draft-ietf-teas-ietf-
             network-slices-12.txt>.

   [I-D.ietf-lsr-flex-algo] Psenak, P., Hegde, S., Filsfils, C.,
             Talaulikar, K., and A. Gulko, "IGP Flexible Algorithm",
             draft-ietf-lsr-flex-algo-20 (work in progress), May 2022.

   [I-D.ietf-spring-segment-routing-policy] Filsfils, C., Talaulikar,
             K., Voyer, D., Bogdanov, A., and P. Mattes, "Segment
             Routing Policy Architecture", Work in Progress, Internet-
             Draft, draft-ietf-spring-segment-routing-policy-22, 22
             March 2022, <http://www.ietf.org/internet-drafts/draft-
             ietf-spring-segment-routing-policy-22.txt>.

6.2. Informative References

   [I-D.dong-teas-hierarchical-ietf-network-slice] Dong, J., and Z. Li,
             "Considerations about Hierarchical IETF Network Slices",
             Work in Progress, Internet-Draft, draft-dong-teas-
             hierarchical-ietf-network-slice-01, 7 March 2022,
             <http://www.ietf.org/internet-drafts/draft-dong-teas-
             hierarchical-ietf-network-slice-01.txt>.

Zhang, et al.            Expires July, 2024                   [Page 7]
Internet-Draft   AAA for Hierarchical Network Slices       January 2024

   [I-D.ietf-6man-enhanced-vpn-vtn-id] Dong, J., Li, Z., Xie, C., Ma,
             C., and G. Mishra, "Carrying Virtual Transport Network
             (VTN) Identifier in IPv6 Extension Header", Work in
             Progress, Internet-Draft, draft-ietf-6man-enhanced-vpn-
             vtn-id-00, 5 March 2022, <http://www.ietf.org/internet-
             drafts/draft-ietf-6man-enhanced-vpn-vtn-id-00.txt>.

   [I-D.cheng-spring-srv6-encoding-network-sliceid] Cheng, W., Lin, C.,
             Gong, L., Zadok, S., and X. Wang, "Encoding Network Slice
             Identification for SRv6", Work in Progress, Internet-
             Draft, draft-cheng-spring-srv6-encoding-network-sliceid-
             04, 8 July 2022, <http://www.ietf.org/internet-
             drafts/draft-cheng-spring-srv6-encoding-network-sliceid-
             04.txt>.

   [I-D.decraene-mpls-slid-encoded-entropy-label-id] Decraene B.,
             Filsfils, C., Henderickx W., Saad T., Beeram V., "Using
             Entropy Label for Network Slice Identification in MPLS
             networks", Work in Progress, Internet-Draft, draft-
             decraene-mpls-slid-encoded-entropy-label-id-04, 14 June
             2022, <http://www.ietf.org/internet-drafts/draft-decraene-
             mpls-slid-encoded-entropy-label-id-04.txt>.

   [I-D.li-mpls-enhanced-vpn-vtn-id] Li, Z. and J. Dong, "Carrying
             Virtual Transport Network Identifier in MPLS Packet", Work
             in Progress, Internet-Draft, draft-li-mpls-enhanced-vpn-
             vtn-id-02, 7 March 2022, <http://www.ietf.org/internet-
             drafts/draft-li-mpls-enhanced-vpn-vtn-id-02.txt>.

  7. Acknowledgments

   The authors would like to thank the following for their valuable
   contributions of this document:

   TBD

Zhang, et al.            Expires July, 2024                   [Page 8]
Internet-Draft   AAA for Hierarchical Network Slices       January 2024

Authors' Addresses

   Xiaoqiu Zhang
   China Mobile
   Email: zhangxiaoqiu@chinamobile.com

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

   Yuanxiang Qiu
   New H3C Technologies
   Email: qiuyuanxiang@h3c.com

Zhang, et al.            Expires July, 2024                   [Page 9]