NFVRG R. Gu Internet-Draft S. Hu Intended status: Informational China Mobile Expires: January 3, 2018 July 2, 2017 Control and User Plane Separation Architecture of BNG draft-gu-nfvrg-cloud-bng-architecture-01 Abstract This document defines the new architecture of BNG devices with control plane (CP) and user plane (UP) separation. BNG-CP is a user control management component while BNG-UP takes responsibility as the network edge and user policy implementation componenet. Both BNG-CP and BNG-UP are core components for fixed broadband services and deployed separately at different network layer in actual network. 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 http://datatracker.ietf.org/drafts/current/. 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Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of Gu & Hu Expires January 3, 2018 [Page 1] Internet-Draft C/U Separated BNG Architecture July 2017 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Definition of terms . . . . . . . . . . . . . . . . . . . . . 2 4. C/U separated BNG architecture . . . . . . . . . . . . . . . 3 5. C/U separated BNG use case . . . . . . . . . . . . . . . . . 4 6. Advantages of C/U seperated BNG . . . . . . . . . . . . . . . 8 7. Security Considerations . . . . . . . . . . . . . . . . . . . 8 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 9. Normative References . . . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 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 separation is to extract and centralize the user management function of multiple BNG devices forming a separate and concentrated CP, while UP takes function as traditional router's control plane 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 Gu & Hu Expires January 3, 2018 [Page 2] Internet-Draft C/U Separated BNG Architecture July 2017 MANO:Management and Orchestration NFV:Network Function Virtualization PPPoE:Point to Point Protocol over Ethernet UP: User Plane 4. C/U separated 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 module or device which can be called BNG-CP (Control Plane). The reserved functions such as router function and forwarding engine can be deployed in the form of BNG User Plane. Thus the Cloud-based BNG architecture is made up of control plane and user plane. +--------------------------------------------------------------+ |+----------+ +---+ +----------+ +------++------++-----------+ | || 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 (2)AAA and RADIUS:cooperation with the RADIUS server and others to implement AAA for access users Gu & Hu Expires January 3, 2018 [Page 3] Internet-Draft C/U Separated BNG Architecture July 2017 (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 5. C/U separated BNG use case Gu & Hu Expires January 3, 2018 [Page 4] Internet-Draft C/U Separated BNG Architecture July 2017 +------------------------------------------------------------------+ | Neighboring policy and resource management systems | | | | +-------------+ +-----------+ +---------+ +----------+ | | |Radius Server| |DHCP Server| | EMS | | MANO | | | +-------------+ +-----------+ +---------+ +----------+ | +--------------------------------+---------------------------------+ | | | +-----------------+-----------------+ | | | BNG-CP | | | +---------------+------------+------+ Service| Control| Management| ||| Interface| Interface| Interface| ||| (VXLAN-GPE)| (OF,etc.)| (Netconf)| ||| | | | ||| +--------------+------------+ +---------------------------+ | | | | | BNG-UP | | BNG-UP | | | | | +-------------+-------------+ +--------------+------------+ | | | | +-------------+-------------+ +--------------+------------+ | | | | | Access Network | | Access Network | | | | | +-+-----------+-----------+-+ +-+--------+-----------+----+ | | | | | | | | | | | | | | | | | | +-----++ +----+-+ +---+--+ +----+-+ +----+-+ +--+---+ |User11| |User12| ... |User1N| |User21| |User22| ... |User2N| +------+ +------+ +------+ +------+ +------+ +------+ Figure 2: Cloud BNG use case In the actual deployment, a C/U separated BNG device is composed of CP and UPs. CP is centralized deployed which takes responsiblity of a user control management component managing UP's resources such as the user entry and forwarding policy. And UP is distributed in the bottom acting as a network edge and user policy implementation component. Gu & Hu Expires January 3, 2018 [Page 5] Internet-Draft C/U Separated BNG Architecture July 2017 In order to fulfill a service, Neighboring policy and resource management systems is deployed outside. In the neighboring system, different service systems such as RADIUS server,DHCP server and EMS are included. Besides if BNG-CP is virtualized as a NFV. The NFV infrastructure management system MANO is also included here. BNG-CP has connections with the outside neighboring systems to transmit management traffic. There are three kinds of interfaces between BNG-CP and BNG-UP according to its traffic catergories: Service Interface, Control Interface, and Management Interface. Service Interface is used to transmit PPPoE/IPoE packets for the authentication. Control Interface is used for setting forwarding entries on UP. Some choose OpenFlow as the protocol. Management Interface is used to carry out basic configurations through NETCONF. Besides, now we have three related drafts which describes these interfaces in detail. One is VXLAN-GPE extention draft for C/U separated BNG related with Servie Interface in [draft-huang-nov3- vxlan-gpe-extension-for-vbng-00]. One is YANG data model for Management Interface in [draft-hu-opsawg-cu-separation-yang-model- 00]. The other is the information model covering Control Interface and Management Interface which makes the abstraction of information in modeling in [draft-wcg-i2rs-cu-separation-info-model-01]. Gu & Hu Expires January 3, 2018 [Page 6] Internet-Draft C/U Separated BNG Architecture July 2017 +-------------------+ | | | Internet | | | +---------^---------+ | +---+---+ | | +------------------------+ | CR | | | | | | +--------+ | +---^---+ | +------+ Radius | | | | | +--------+ | | | +--+---+ | +---+---+ | | | +--------+ | | +--------------+ | +--+ DHCP | | | BNG-UP+--------------+ | BNG | +--------+ | | +--------------+ | -cp | | +---^---+ | | | +--------+ | | | | +--+ EMS | | | | | | +--------+ | +---+---+ | +--+---+ | | | | | +--------+ | | OLT | | +------+ MANO | | | | | +--------+ | +---^---+ | Management|Network | | +------------------------+ +---+---+ | USER | +-------+ Figure 3: User Dialup process In the C/U seprated BNG architecture, there are several processes when a home user accesses the Internet. (1)User dialup packets of PPPoE or IPoE from BNG-UP which will send to BNG-CP from BNG-UP's Service Interface. (2)BNG-CP processes the dialup packet. Confirming with the outside neighboring systems in the management network, BNG-CP makes the decision to permit or deny of the dial through certification. (3)After that, BNG-CP tells UP to do the responding forwarding actions with related policies. (4)If the user is certificated and permitted, the UP forwards the traffic into the Internet with related policies such as limited Gu & Hu Expires January 3, 2018 [Page 7] Internet-Draft C/U Separated BNG Architecture July 2017 bandwidth, etc. Otherwise, the user is denied to access the Internet. 6. Advantages of C/U seperated BNG Due to the bandnew C/U separated BNG architecture, there are a lot of brilliant advantages. (1)Resources can be central controlled and balanced Centralized control plane takes the responsibility of control and management. Thus it has the overall view of resources and can distribute the resources as required. (2)Device can be more efficient in extension Control plane and user plane can be extended separately according to different situations such as the session overload and extremely high throughput. (3)Management can be much easier as the BNG-CP is the only one facing to the outside system such as EMS, DHCP server, Radius and so on. (4)BNG-CP can be virtualized as a VNF with its management of MANO. (5)BNG-UP can be a virtual machine or physical device as demand. 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, . [RFC2234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, DOI 10.17487/RFC2234, November 1997, . Gu & Hu Expires January 3, 2018 [Page 8] Internet-Draft C/U Separated BNG Architecture July 2017 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 Gu & Hu Expires January 3, 2018 [Page 9]