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NFVRG                                                              R. Gu
Internet-Draft                                                     S. Hu
Intended status: Informational                              China Mobile
Expires: September 1, 2017                             February 28, 2017


   Control and User Plane Seperation Architecture of Cloud based BNG
                draft-gu-nfvrg-cloud-bng-architecture-00

Abstract

   This document defines the architecture of Clond-based BNG devices
   with control plane (CP) and user plane (UP) seperation.  Both BNG-CP
   and BNG-UP are core components for fixed broadband services and
   deployed seperately at different network layer.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
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   This Internet-Draft will expire on September 1, 2017.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  Definition of terms . . . . . . . . . . . . . . . . . . . . .   2
   4.  Cloud-based BNG architecture  . . . . . . . . . . . . . . . .   3
   5.  Cloud_BNG use case  . . . . . . . . . . . . . . . . . . . . .   4
   6.  Cloud_BNG related interfaces  . . . . . . . . . . . . . . . .   6
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   9.  Normative References  . . . . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   BNG device is defined as an Ethernet-centric IP edge router, and the
   aggregation point for the user traffic.  It performs Ethernet
   aggregation and packets forwarding via IP/MPLS, and supports user
   management, access protocols termination, QoS and policy management,
   etc.

   The basic idea of control plane and user plane seperation is to
   extract and centralize the user management function of multiple BNG
   devices forming a separate CP, while UP takes function as router CP
   and BNG forwarding plane.  Thus a BNG is constructed of CP and UP
   which is benefit in cloud-based BNG with the advantages of resource
   utilization improvement, resource control centralization, new service
   rapid provision and so on.

2.  Terminology

   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 [RFC2119].

3.  Definition of terms

   AAA:Authentication Authorization Accounting

   BNG:Broadband Network Gateway

   CP:Control Plane

   DHCP:Dynamic Host Configuration Protocol

   MANO:Management and Orchestration

   NFV:Network Function Virtualization



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   PPPoE:Point to Point Protocol over Ethernet

   UP: User Plane

4.  Cloud-based BNG architecture

   There are two parts of functions in traditional BNG: one is user
   access management function, the other is router function.  While in
   cloud-based BNG, we find out that tearing these two functions apart
   can make a difference.  Actually the user management function can be
   centralized deployed as a concentrated control plane.  The reserved
   functions such as router functi on and forwarding engine can be
   deployed in the form of user plane.  Thus the Cloud-based BNG
   architecture is made up of control plane and user plane.

   +------------------------------------------------------------------+
   |        Neighboring policy and resource management systems        |
   |                                                                  |
   |   +-------------+   +-----------+   +---------+   +----------+   |
   |   |Radius Server|   |DHCP Server|   |   EMS   |   |   MANO   |   |
   |   +-------------+   +-----------+   +---------+   +----------+   |
   +------------------------------------------------------------------+

   +------------------------------------------------------------------+
   |                       CU-separated BNG system                    |
   | +--------------------------------------------------------------+ |
   | |+----------+ +---+ +----------+ +------++------++-----------+ | |
   | || Address  | |AAA| |Subscriber| |Radius||PPPoE/||    UP     | | |
   | ||management| |   | |management| |      ||IPoE  ||management | | |
   | |+----------+ +---+ +----------+ +------++------++-----------+ | |
   | |                              CP                              | |
   | +--------------------------------------------------------------+ |
   | +---------------------------+      +--------------------------+  |
   | |  +------------------+     |      |  +------------------+    |  |
   | |  | Routing control  |     |      |  | Routing control  |    |  |
   | |  +------------------+     | ...  |  +------------------+    |  |
   | |  +------------------+     |      |  +------------------+    |  |
   | |  |Forwarding engine |     |      |  |Forwarding engine |    |  |
   | |  +------------------+  UP |      |  +------------------+  UP|  |
   | +---------------------------+      +--------------------------+  |
   +------------------------------------------------------------------+

               Figure 1: Architecture of C/U Seperation BNG

   The CP is a user control management component that supports

   (1)address management:unified address pool management




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   (2)AAA and RADIUS:cooperation with the RADIUS server and others to
   implement AAA for access users

   (3)Subscriber management:user entry management and forwarding policy
   management

   (4)PPPoE/IPoE:process user dialup packets of PPPoE/IPoE

   (5)UP management:management of UP interface status, and the setup,
   deletion, maintenance of channels between CP and UP

   The UP is a network edge and user policy implementation component,
   including

   (1)Control plane functions including routing, multicast, and MPLS

   (2)forwarding plane functions including traffic forwarding, QoS, and
   traffic statistics collection

   (3)Other functions such as configuration of routing services through
   EMS Cooperation with the DHCP server or use of the local

   Neighboring policy and resource management systems deploys different
   service systems such as RADIUS server, DHCP server and EMS.  Besides
   NFV infrastructure management system MANO is included in resource
   mangement systems.  All of them have connections with BNG CP.

5.  Cloud_BNG use case

   In the next generation of Telecom Integrated Cloud (TIC) focusing on
   content and traffic instead of voice, there can be several layers
   which we call core TIC layer and edge TIC layer.

   Core TIC layer: mainly responsible for control, management, and
   scheduling functions and carries control-plane NE, centralized media-
   plane NE, CDN device, and backbone network traffic.  BNG-CP is
   deployed in this layer.

   Edge TIC layer: oriented towards major media planes and is mainly
   responsible for terminating media traffic.  BNG-CP is deployed in
   this layer.










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                         ----------------
                   ///---                ---\\\
               ////                            \\\\
            /// +--------------------------------+ \\\
          //    |           Orchestrator         |    \\
         |      +--------------------------------+      |
        |                                                |
       |+----------------+   +-------+                    |
       || SDN CONTROLLER |   |  CSCF |                    |
       |+----------------+   +-------+                    |
        |                                                |
         |      **********   +-------+  +-------+       |
          \\    * BNG CP *   |  MME  |  | 5G CP |     //
            \\\ **********   +-------+  +-------+  ///
               \\\\                            ////
                   \\\---                ---///           CORE TIC LAYER
                         ----------------

                                        +-------+
                                        | 5G UP |
                                        +-------+
         -----                 -----                -----
     ///-     -\\\         ///-     -\\\         //-     -\\\
    /  *********  \       /  +-------+  \      /             \
   |   *BNG  UP*   |     |   |  SBC  |   |    |               |
  |    *********    |   |    +-------+    |  |    +-------+    |
  |    +-------+    |   |    +-------+    |  |    |  CDN  |    |
   |   | S-CPE |   |     |   |   GW  |   |    |   +-------+   |
    \  +-------+  /       \  +-------+  /      \             /
     \\\-     -///         \\\-     -///        \\\-     -///
         -----                 -----                -----

     Fixed network         Mobile network           Content
      media plane           media plane           media plane

                                                         EDGE TIC LAYER

                   Figure 2: C/U Seperation BNG USE CASE

   In the Core TIC layer, BNG CP is deployed including the BNG Service
   and Subscriber Session Control function which could be virtualized
   and centralized.  The functional components inside the BNG Service
   and Subscriber Session Control can be implemented as VNFs and run in
   x86 servers.

   In the Edge TIC layer, the routing and forwarding parts could be
   distributed as BNG UP.  Due to high packet processing performance
   requirements, BNG UP can remain as physical devices.  If it's in some



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   practical situation, the number of subscribers is relatively small,
   the BNG UP can be virtualized as well.

6.  Cloud_BNG related interfaces

   TBD.

7.  Security Considerations

   None.

8.  IANA Considerations

   None.

9.  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,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC2234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", RFC 2234, DOI 10.17487/RFC2234,
              November 1997, <http://www.rfc-editor.org/info/rfc2234>.

Authors' Addresses

   Rong Gu
   China Mobile
   32 Xuanwumen West Ave, Xicheng District
   Beijing, Beijing  100053
   China

   Email: gurong_cmcc@outlook.com


   Shujun Hu
   China Mobile
   32 Xuanwumen West Ave, Xicheng District
   Beijing, Beijing  100053
   China

   Email: hushujun@chinamobile.com.com







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