Network Working Group Fangwei. Hu Internet-Draft ZTE Intended status: Standards Track Bhumip. Khasnabish Expires: September 2, 2013 ZTE USA Inc. Mar 2013 I2RS overlay use case draft-hu-i2rs-overlay-use-case-00.txt Abstract This document proposes an overlay network use case. The forwarding routers network is an overlay structure. There are two kinds of forwarding routers: Edge Router(ER) and Core Routers(CR). Edge Router encapsulates format data based on the tunnel type, which are established among Edge Routers. Core Router would be very simple and cheap. It focus on the encapsulation data forwarding. In order to reduce the equipment cost of Edge Routers, the network virtualization is provided in this document. 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/. 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 September 2, 2013. Copyright Notice Copyright (c) 2013 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 publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect Hu & Khasnabish Expires September 2, 2013 [Page 1] Internet-Draft I2RS Overlay Mar 2013 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 . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Overlay Network Structure . . . . . . . . . . . . . . . . . . . 3 2.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2. The Benefit of Overlay Network Structure . . . . . . . . . 5 2.3. Core Router Requirements . . . . . . . . . . . . . . . . . 5 2.4. Edge Router Requirement . . . . . . . . . . . . . . . . . . 5 3. Network Virtualization(NV) . . . . . . . . . . . . . . . . . . 6 3.1. Benefits of Network Virtualization . . . . . . . . . . . . 6 3.2. Applications and Requirements . . . . . . . . . . . . . . . 6 3.3. Network Virtualization . . . . . . . . . . . . . . . . . . 7 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 8 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 8 7. Normative References . . . . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9 Hu & Khasnabish Expires September 2, 2013 [Page 2] Internet-Draft I2RS Overlay Mar 2013 1. Introduction As modern networks grow in scale and complexity, the need for rapid and dynamic control increases. I2RS([I2RS-FRM]) provide a new routing system framework to meet the requirement. There is a programmable interface for the forwarding router. All the forwarding routers should support I2RS agent to communicate with controllers. The forwarding routers gather the traffic and topology information, report to the controllers, and receive the policy from controllers. Besides the idea of programmable and open interface, another key feature is forwarding plane and control plane separation in the I2RS and software define network. Some of the control and computing function could be separation from traditional routers. By this way, we hope that the service and data encapsulation are all done in the routers of the edge of network, and the routers in the core part are only focus on data forwarding. The core routers RIB table could only store the network(or equipment) IP prefix, and does not store user(or end station) IP prefix anymore. The RIB and FIB table capability of core routers would be reduced significantly, and the equipment cost could be lower. The full mesh tunnel is required for the edge Routers. This is actually an overlay network structure. The forwarding routers in the overlay network are divides into two kinds based on the roles in the network: CR(Core Router) and ER(Edge Router).The Edge Routers encapsulate the forwarding data based on the tunnel type, gather topology information, and report traffic to the controller, while Core Routers focus on fast data forwarding and receive only policy related information(metadata)from the controller. 2. Overlay Network Structure Hu & Khasnabish Expires September 2, 2013 [Page 3] Internet-Draft I2RS Overlay Mar 2013 2.1. Overview +--------+ +--------+ | Edge +--+ +---| Edge | | Router | | | | Router | +--------+ | | +--------+ | +------+ +------+ | | | Core | |Core | | +--|Router|---------- |Router|-+ +------+ +------+ / \ / \ +--------+ / physical topology \ +--------+ | Edge |--+ +----| Edge | | Router | | Router | +--------+ +--------+ =================================================================== +--------+ +--------+ | Edge |--+ +----| Edge | | Router | | | | Router | +--------+ | ................... | +--------+ | . . | | . * * . | +----. * * .-----+ /. * * . / . * * . / .Overlay * Tunnel . +--------+ / . * * .-----+ +--------+ | Edge +--+ . * * . | | Edge | | Router | . * * . +----| Router | +--------+ ...*............*.. +--------+ Logical Tunnel Figure 1 Overlay Structure The overlay structure is shown in Figure 1. The upper half part of the Figure show a physical network. The Edge Routers are located in the edge of the overlay network, and are logically connected through Core Routers.The services and data encapsulation are done in the edge routers. The Core Routers are very simple; and focus on the data forwarding, and may not perceive any distinction among the tunnels to/from Edge Routers. The lower half of the Figure shows a logical tunnel network. All the Edge Routers are connected via a logical-full mesh tunnel-based connection among them. The tunnel could be IP/MPLS/OTN tunnel. Edge Router encapsulates/decapsulates the data based on the tunnel type. If tunnel type is IP network, the encapsulation format would be IP Hu & Khasnabish Expires September 2, 2013 [Page 4] Internet-Draft I2RS Overlay Mar 2013 over GRE, or IP over UDP. If tunnel is MPLS network, the encapsulation format is IP over MPLS, which is similar to the MPLS data format. If tunnel is OTN, the tunnel format is IP/Ethernet over ODU. 2.2. The Benefit of Overlay Network Structure (1) Lower cost down for Core Routers: For the Core Router, it is not required to compute route, and distribute protocol signal. The Core Routers only store the equipment IP prefix, and do not store user IP prefix any more. The RIB and FIB table for core Router are very small. The size routing tables in the Core Routers does not increase and remains stable with the growth of the numbers of users. (2) Improved network security: The overlay network structure improves network security by splitting(and hence isolating)the provider equipment and user station. The attacks from hacker to core routers would therefore be separated by the edge routers. (3) Support of network virtualization: Some of the control and computing function could be separated from Edge Router and be done by controller. The edge router in the future is a hardware platform. The service, policy ,and other control function, such as route computing, signal distribution can be furnished by special physical/virtual servers. The network virtualization for Edge Router is discussed in section 3. 2.3. Core Router Requirements The Core Router performs the following functions: (1) Core Routers mainly focus on fast forwarding encapsulated data. (2) The control plane is very simple. It announces and floods the topology information. (3) For compatibility reasons, Route computation may be needed, but is not necessary. 2.4. Edge Router Requirement The edge Router performs the following functions: (1) Access and resources management: Edge Routers support user Access authentication, authorization, and resource control and management. When there is new user access network, the edge router support user access authentication, authorization. If Hu & Khasnabish Expires September 2, 2013 [Page 5] Internet-Draft I2RS Overlay Mar 2013 the subscriber is legal and registered, he/she should should pass the access authentication and authorization tests. (2) Topology management:Edge Router gathers the network topology information and reports the topology to the controller. When the topology changes, the edge router reports the changes as well. (3) Policy management: Edge Router identifies the policy from The I2RS Commissioner([I2RS-Policy]). (4) Service management: Edge Router should identifies the services and performs the appropriate encapsulation. (5) Route and signal protocol management: Edge Router computes route based on the topology information received from other edge router and core router. (6) Tunnel control and management: Edge Routers manage and maintain tunnel information. All the edge routers are connected over logical full-mesh based tunnel network. (7) Traffic analysis and reporting: Edge router monitors the data traffic, and reports the traffic updates/changes. 3. Network Virtualization(NV) 3.1. Benefits of Network Virtualization (1) NV reduces ER complexity and equipment costs. (2) NV allows flexibility and rapid deployment of new services; services can also be quickly scaled up/down based on demands. (3) Seamless support of scalability and reliability (4) NV allows flexibility and simplicity of function combination, for co-existence with hardware based network platform. An ER could be utilized both as BRAS, Firewall, or NAT equipment on the same hardware platform. 3.2. Applications and Requirements Hu & Khasnabish Expires September 2, 2013 [Page 6] Internet-Draft I2RS Overlay Mar 2013 (1) Tunnel gateway elements: IPSec/SSL VPN gateway. (2) Traffic analytics: DPI, QoS measurement, SLA agent. (3) Converged and network-wide functions: AAA Server, policy control and charging platform. (4) Security function: Firewalls, virus scanners, instruction detection and prevention systems. 3.3. Network Virtualization Edge routers can support network virtualization, An ER can be a hardware based platform, and the other necessary functions can be supported via separate servers A programmable interface between functional server and edge router can be used to support this paradigm. When there is new service, we only need to add a new server to support that service, and there may be minimal or no changes required to the edge router. Hu & Khasnabish Expires September 2, 2013 [Page 7] Internet-Draft I2RS Overlay Mar 2013 +--------------------+ +-------------------+ | +------+ +------+ | | +------+ +------+ | | |DPI | |NAT | | | |DPI | |NAT | | | |Server| |Server| | | |Server| |Server| | | +------+ +------+ | | +------+ +------+ | | +------+ | | +------+ | | | QOS | | | | QOS | | | |Server| | | |Server| | | +------+ | | +------+ | +-----+--------------+ virtualization +---------------+---+ ======|=======================================================|==== . . | +------------------------------------------------+ . . | +--------+ +-------+ | | |- +-->| Edge | | Edge |<--+---. . | | Router | | Router| | | | | +--------+ +-------+ | . . | Overlay Network | | | | +-------+ +-------+ | . . | | Core |-----| Core | | | | | | Router| | Router| | . . | +-------+ +-------+ | | | | | . . | +--------+ +-------+ | | +--+->| Edge + | Edge |<--+---+ | | Router | | Router| | | +--------+ +-------+ | +------------------------------------------------+ Figure 2: Network Virtualization 4. Security Considerations TBD 5. Acknowledgements TBD 6. IANA Considerations TBD Hu & Khasnabish Expires September 2, 2013 [Page 8] Internet-Draft I2RS Overlay Mar 2013 7. Normative References [I2RS-FRM] Atlas, A., Nadeau, T., and D. Ward, "Interface to the Routing System Framework", draft-ward-i2rs-framework-01 (work in process), July 2012. [I2RS-Policy] Atlas, A., Hares, S., and J. Halpern, "A Policy Framework for the Interface to the Routing System", draft-atlas-i2rs-policy-framework-00 (work in process), September 2012. Authors' Addresses Fangwei Hu ZTE No.889 Bibo Rd Shanghai, 201203 China Phone: +86 21 68896273 Email: hu.fangwei@zte.com.cn Bhumip Khasnabish ZTE USA Inc. 55 Madison Avenue, Suite 160 Morristown, New Jersey 07960 USA Phone: +001-781-752-8003 Email: Bhumip.khasnabish@zteusa.com Hu & Khasnabish Expires September 2, 2013 [Page 9]