SUPA W.Liu Internet Draft J. Strassner Intended status: Informational G. Karagiannis Expires: October 2016 Huawei Technologies M. Klyus NetCracker J.Bi Tsinghua University April 5, 2016 SUPA policy-based management framework draft-liu-supa-policy-based-management-framework-00.txt 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 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 October 5, 2016. Copyright Notice Copyright (c) 2016 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 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. Liu, et al. Expires October 5, 2016 [Page 1] Internet-Draft SUPA policy based management framework April 2016 Abstract Simplified Use of Policy Abstractions (SUPA) defines a set of rules that define how services are designed, delivered, and operated within an operator's environment independent of any one particular service or networking device. This document describes the SUPA basic architecture, its elements and interfaces. Table of Contents 1. Introduction ................................................ 2 2. Framework for Generic Policy-based Management................ 3 2.1. Overview ............................................... 3 2.2. Operation .............................................. 7 2.3. The GPIM and the EPRIM.................................. 8 2.4. Creation of Generic YANG Modules........................ 8 3. Security Considerations...................................... 9 4. IANA Considerations ......................................... 9 5. Contributors ................................................ 9 6. Acknowledgments ............................................. 9 7. References ................................................. 11 7.1. Normative References................................... 11 7.2. Informative References................................. 12 1. Introduction The rapid growth in the variety and importance of traffic flowing over increasingly complex enterprise and service provider network architectures makes the task of network operations and management applications and deploying new services much more difficult. In addition, network operators want to deploy new services quickly and efficiently. Two possible mechanisms for dealing with this growing difficulty are the use of software abstractions to simplify the design and configuration of monitoring and control operations and the use of programmatic control over the configuration and operation of such networks. Policy-based management can be used to combine these two mechanisms into an extensible framework. Policy rules can be used to express high-level network operator requirements directly, or from a set of management applications, to a network management or element system. The network management or element system can then control the configuration and/or monitoring of network elements and services. Simplified Use of Policy Abstractions (SUPA) will define a generic policy information model (GPIM) [SUPA-info-model] for use in network Liu, et al. Expires October 5, 2016 [Page 2] Internet-Draft SUPA policy based management framework April 2016 operations and management applications. The GPIM defines concepts and terminology needed by policy management indepednent of the form and content of the policy rule. The ECA Policy Rule Information Model (EPRIM) [SUPA-info-model] extends the GPIM to define how to build policy rules according to the event-condition-action paradigm. Both the GPIM and the EPRIM are targeted at controlling the configuration and monitoring of network elements throughout the service development and deployment lifecycle. The GPIM and the EPRIM will both be translated into corresponding YANG [RFC6020] modules that define policy concepts, terminology, and rules in a generic and interoperable manner; additional YANG modules may also be defined from the GPIM and/or EPRIM to manage specific functions. The key benefit of policy management is that it enables different network elements and services to be instructed to behave the same way, even if they are programmed differently. Management applications will benefit from using policy rules that enable scalable and consistent programmatic control over the configuration and monitoring of network elements and services. 2. Framework for Generic Policy-based Management This section briefly describes the design and operation of the SUPA policy-based management framework. 2.1. Overview Figure 1 shows a simplified functional architecture of how SUPA is used to define policies for creating network element configuration and monitoring snippets. SUPA uses the GPIM to define a consensual vocabulary that different actors can use to interact with network elements and services. The EPRIM defines a generic structure for imperative policies. The GPIM, as well as the combination of the GPIM and EPRIM, are converted to generic YANG data modules. The IETF produces the modules, and IANA is used to register the module and changes to it. In one possible approach, SUPA Generic & ECA Policy YANG Data modules together with the Resource and Service YANG data models specified in IETF (which define the specific elements that will be controlled by policies) are used by the Service Interface Logic. This Service Interface Logic creates appropriate input mechanisms for the operator to define policies (e.g., a web form or a script) for creating and managing the network configuration. The operator interacts with the interface, which is then translated to configuration snippets. Liu, et al. Expires October 5, 2016 [Page 3] Internet-Draft SUPA policy based management framework April 2016 Note that YANG models may not exist. In this case, the SUPA generic policy YANG data modules serve as an extensible basis to develop new YANG data models for the Service Interface Logic to create appropriate input mechanisms for the operator to define policies. This transfers the work specified by the Resource and Service YANG data models specified in IETF into the Service Interface Logic, which is then translated to configuration snippets. +---------------------+ +----------+ \| SUPA Generic Policy | | IETF |---+----+ Information Model | +----------+ | /| | | +---------+-----------+ | | Assignments | | Defines Policy Concepts and Manage | | Content | \|/ | +---------+-----------+ | \| SUPA GPIM and EPRIM | +----+ Generic YANG | /| Data Modules | +---------+-----------+ * * Possible * Approach * +--------------------------------*----------------------------------+ | Management System * | | * | | \*/ | | Fills +----------+----------+ +---------------+ | | +--------+ Forms \| Service Interface |/ | Resource and |/ | +------+ | |Operator|----------+ Logic +----| Service YANG |------| IETF | | +--------+ Runs /| (locally defined |\ | Data Models |\ | +------- | Scripts | forms, scripts,...) | +---------------+ | | +----------+----------+ | | | | | \|/ | | +-------+--------+ | | | Local Devices | | | | and Management | | | | Systems | | | +----------------+ | +-------------------------------------------------------------------+ Figure 1 SUPA Framework Liu, et al. Expires October 5, 2016 [Page 4] Internet-Draft SUPA policy based management framework April 2016 Figure 1 is exemplary. The Operator actor shown in Figure 1 can interact with SUPA in other ways not shown in Figure 1. In addition, other actors (e.g., an application developer) that can interact with SUPA are not shown for simplicity. The EPRIM defines an Event-Condition-Action (ECA) policy as an example of imperative policies. An ECA policy rule is activated when its event clause is true; the condition clause is then evaluated and, if true, signals the execution of one or more actions in the action clause. Imperative policy rules require additional management functions, which are explained in section 2.2 below. Figure 2 shows a SUPA Policy Model creating and communicating policy rules to two different Network Manager and Network Controller elements. The Generic Policy Information Model (GPIM) was used to construct policies. The GPIM defines generic policy concepts, as well as two types of policies: ECA policy rules and declarative policy statements. An ECA policy rule is activated when its event clause is true; the condition clause is then evaluated and, if true, signals the execution of one or more actions in the action clause. This type of policy explicitly defines the current and desired states of the system being managed. A set of Generic Policy Data Models are then created from the GPIM. These YANG data model policies are then used to control the configuration of network elements that model the service(s) to be managed using policy. +-----------------------------------------------------------------+ | SUPA Policy Model | | | | +----------------------------------+ | | | Generic Policy Information Model | | | +----+------------------------+----+ | | D D | | D \ / | | D +------------+--------------+ | | D | ECAPolicyRule Information | | Liu, et al. Expires October 5, 2016 [Page 5] Internet-Draft SUPA policy based management framework April 2016 | D | Model (EPRIM) | | | D +------------+--------------+ | | +----------------D------------------------D----------------+ | | | D SUPA Policy Data Model D | | | | \ / D | | | |+---------------+-----------+ D | | | || Generic Policy Data Model | D | | | |+-------------------+-------+ D | | | | D D | | | | \ / \ / | | | | +--+--------------------+--------------+ | | | | | ECA PolicyRule Data Model | | | | | +--------------------------------------+ | | | +------------------------------+---------------------------+ | | | | | | | +---------------------------------|-------------------------------+ | | NETCONF/RESTCONF +-------------+--------+ C C C C \ / \ / +----------------+-----------+ +-------+--------------------+ | Network Manager/Controller | | Network Manager/Controller | | +--------------------+ | | +---------------------+ | | | Network Resource | | | | Network Resource | | | | Data Model | | | | Data Model | | | +--------------------+ | | +---------------------+ | +---+---+---+----------------+ +-----+---+---+--------------+ / \ / \ / \ / \ / \ / \ C C C C C C C C C C C C C C C C C C \ / \ / \ / \ / \ / \ / NE1 NE2 NEn NE1 NE2 NEn Figure 2 SUPA Policy Model Framework In Figure 2: A double-headed arrow with Cs means communication; A double-headed arrow with Ds means derived from; The network elements used in this framework are: Liu, et al. Expires October 5, 2016 [Page 6] Internet-Draft SUPA policy based management framework April 2016 SUPA Policy Model: represents one or more policy modules that contain the following entities: Generic Policy Information Model: a model for defining policy rules that are independent of data repository, data definition, query, and implementation languages, and protocol. This model is abstract and is used for design; it MUST be turned into a data model for implementation. Generic Policy Data Model: a model of policy rules for that are dependent of data repository, data definition, query, and implementation languages, and protocol. ECA Policy Rule Information Data Model (EPRIM): represents a policy rule as a statement that consists of an event clause, a condition clause, and an action clause. This type of Policy Rule explicitly defines the current and desired states of the system being managed. This model is abstract and is used for design; it MUST be turned into a data model for implementation. ECA Policy Rule Data Model: a model of policy rules derived from EPRIM, consist of an event clause, a condition clause, and an action clause. NM/NC: Network Manager / Controller, which represents one or more entities that are able to control the operation and management of a network infrastructure (e.g., a network topology that consists of Network Elements). Network Resource Data Model: a model of the physical and virtual network topology including the resource attributes (e.g., data rate or latency of links) and operational parameters needed to support service deployment over the network topology. An example of a network resource data model can be found in [ID.draft-contreras- supa-yang-network-topo]. Network Element (NE), which can interact with local or remote NM/NC in order to exchange information, such as configuration information, policy enforcement capabilities, and network status. 2.2. Operation SUPA can be used to define various types of policies, including policies that affect services and/or the configuration of individual or groups of network elements. SUPA can be used by a centralized and/or distributed set of entities for creating, managing, interacting with, and retiring policy rules. Liu, et al. Expires October 5, 2016 [Page 7] Internet-Draft SUPA policy based management framework April 2016 The SUPA scope is limited to policy information and data models. SUPA will not define network resource data models or network service data models; both are out of scope. Instead, SUPA will make use of network resource data models defined by other WGs or SDOs. Declarative policies that specify the goals to achieve but not how to achieve those goals (also called "intent-based" policies) are out of scope for the initial phase of SUPA. 2.3. The GPIM and the EPRIM The GPIM provides a common vocabulary for representing concepts that are common to expressing different types of policy, but which are independent of language, protocol, repository, and level of abstraction. This enables different policies at different levels of abstraction to form a continuum, where more abstract policies can be translated into more concrete policies, and vice-versa. For example, the information model can be extended by generalizing concepts from an existing data model into the GPIM; the GPIM extensions can then be used by other data models. The SUPA working group develops models for expressing policy at different levels of abstraction. Specifically, two models are envisioned (both of which are contained in the Generic Policy Information Model block in Figure 1: 1. a generic model (the GPIM) that defines concepts and vocabulary needed by policy management systems independent of the form and content of the policy 2. a more specific model (the EPRIM) that refines the GPIM to specify policy rules in an event-condition-action form 2.4. Creation of Generic YANG Modules An information model is abstract. As such, it cannot be directly instantiated (i.e., objects cannot be created directly from it). Therefore, both the GPIM, as well as the combination of the GPIM and the EPRIM, are translated to generic YANG modules. SUPA will provide guidelines for translating the GPIM (or the combination of the GPIM and the EPRIM) into concrete YANG data models that define how to manage and communicate policies between systems. Multiple imperative policy YANG data models may be instantiated from the GPIM (or the combination of the GPIM and the Liu, et al. Expires October 5, 2016 [Page 8] Internet-Draft SUPA policy based management framework April 2016 EPRIM). In particular, SUPA will specify a set of YANG data models that will consist of a base policy model for representing policy management concepts independent of the type or structure of a policy, and as well, an extension for defining policy rules according to the ECA paradigm. The process of developing the GPIM, EPRIM and the derived/translated YANG data models is realized following the sequence shown below. After completing this process and if the implementation of the YANG data models requires it, the GPIM and EPRIM and the derived/translated YANG data models are updated and synchronized. (1)=>(2)=>(3)=>(4)=>(3')=>(2')=>(1') Where, (1)=GPIM; (2)=EPRIM; (3)=YANG data models; (4)= Implementation; (3')= update of YANG data models; (2')=update of EPRIM; (1') = update of GPIM The YANG module derived from the GPIM contains concepts and terminology for the common operation and administration of policy- based systems, as well as an extensible structure for policy rules of different paradigms. The YANG module derived from the EPRIM extends the generic nature of the GPIM to represent policies using an event-condition-action structure. 3. Security Considerations TBD 4. IANA Considerations This document has no actions for IANA. 5. Contributors The following people all contributed to creating this document, listed in alphabetical order: TBD. 6. Acknowledgments This document has benefited from reviews, suggestions, comments and proposed text provided by the following members, listed in alphabetical order: Andy Bierman. Liu, et al. Expires October 5, 2016 [Page 9] Internet-Draft SUPA policy based management framework April 2016 Part of the initial draft of this document was picked up from previous documents, and this section lists the acknowledgements from them. From "SUPA Value Proposition" [Klyus2016] The following people all contributed to creating this document, listed in alphabetical order: Vikram Choudhary, Huawei Technologies Luis M. Contreras, Telefonica I+D Dan Romascanu, Avaya J. Schoenwaelder, Jacobs University, Germany Qiong Sun, China Telecom Parviz Yegani, Juniper Networks This document has benefited from reviews, suggestions, comments and proposed text provided by the following members, listed in alphabetical order: H. Rafiee, J. Saperia and C. Zhou. The authors of "SUPA Value Proposition" [Klyus2016] were: Maxim Klyus, Ed. , NetCracker John Strassner, Ed. , Huawei Technologies Will(Shucheng) Liu, Huawei Technologies Georgios Karagiannis, Huawei Technologies Jun Bi, Tsinghua University The initial draft of this document merged one document, and this section lists the acknowledgements from it. From "Problem Statement for Simplified Use of Policy Abstractions (SUPA)" [Karagiannis2015] The authors of this draft would like to thank the following persons for the provided valuable feedback and contributions: Diego Lopez, Spencer Dawkins, Jun Bi, Xing Li, Chongfeng Xie, Benoit Claise, Ian Farrer, Marc Blancet, Zhen Cao, Hosnieh Rafiee, Mehmet Ersue, Simon Perreault, Fernando Gont, Jose Saldana, Tom Taylor, Kostas Pentikousis, Juergen Schoenwaelder, John Strassner, Eric Voit, Scott O. Bradner, Marco Liebsch, Scott Cadzow, Marie-Jose Montpetit. Liu, et al. Expires October 5, 2016 [Page 10] Internet-Draft SUPA policy based management framework April 2016 Tina Tsou, Will Liu and Jean-Francois Tremblay contributed to an early version of this draft. The authors of "Problem Statement for Simplified Use of Policy Abstractions (SUPA)" [Karagiannis2015] were: Georgios Karagiannis, Huawei Technologies Qiong Sun, China Telecom Luis M. Contreras, Telefonica Parviz Yegani, Juniper John Strassner, Huawei Technologies Jun Bi, Tsinghua University From "The Framework of Simplified Use of Policy Abstractions (SUPA)" [Zhou2015] The authors of this draft would like to thank the following persons for the provided valuable feedback: Diego Lopez, Jose Saldana, Spencer Dawkins, Jun Bi, Xing Li, Chongfeng Xie, Benoit Claise, Ian Farrer, Marc Blancet, Zhen Cao, Hosnieh Rafiee, Mehmet Ersue, Mohamed Boucadair, Jean Francois Tremblay, Tom Taylor, Tina Tsou, Georgios Karagiannis, John Strassner, Raghav Rao, Jing Huang. Early version of this draft can be found here: https://tools.ietf.org/html/draft-zhou-supa-architecture-00 At the early stage of SUPA, we think quite some issues are left open, it is not so suitable to call this draft as "architecture". We would like to rename it to "framework". Later there may be a dedicated architecture document. The authors of "The Framework of Simplified Use of Policy Abstractions (SUPA)" [Zhou2015] were: Cathy Zhou, Huawei Technologies Luis M. Contreras, Telefonica Qiong Sun, China Telecom Parviz Yegani, Juniper 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. Liu, et al. Expires October 5, 2016 [Page 11] Internet-Draft SUPA policy based management framework April 2016 7.2. Informative References [RFC3198] Westerinen, A., Schnizlein, J., Strassner, J., Scherling, M., Quinn, B., Herzog, S., Huynh, A., Carlson, M., Perry, J., Waldbusser, S., "Terminology for Policy-Based Management", RFC 3198, November, 2001 [RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, October 2010. [RFC7285] R. Alimi, R. Penno, Y. Yang, S. Kiesel, S. Previdi, W. Roome, S. Shalunov, R. Woundy "Application-Layer Traffic Optimization (ALTO) Protocol", September 2014 [SUPA-info-model] J. Strassner, J. Halpern, J. Coleman, "Generic Policy Information Model for Simplified Use of Policy Abstractions (SUPA)", IETF Internet draft, draft-strassner-supa-generic-policy- info-model-04, February 2016 [TR235] J. Strassner, ed., "ZOOM Policy Architecture and Information Model Snapshot", TR245, part of the TM Forum ZOOM project, October 26, 2014 [Karagiannis2015] G. Karagiannis, ed., "Problem Statement for Simplified Use of Policy Abstractions (SUPA)", IETF Internet draft, draft-karagiannis-supa-problem-statement-07, June 5, 2015 [Klyus2016] M. Klyus, ed., "SUPA Value Proposition", IETF Internet draft, draft-klyus-supa-value-proposition-00, Mar 21, 2016 [Zhou2015] C. Zhou, ed., "The Framework of Simplified Use of Policy Abstractions (SUPA)", draft-zhou-supa-framework-02, May 08, 2015 Liu, et al. Expires October 5, 2016 [Page 12] Internet-Draft SUPA policy based management framework April 2016 Authors' Addresses Will(Shucheng) Liu Huawei Technologies Bantian, Longgang District, Shenzhen 518129 P.R. China Email: liushucheng@huawei.com John Strassner Huawei Technologies 2330 Central Expressway Santa Clara, CA 95138 USA Email: john.sc.strassner@huawei.com Georgios Karagiannis Huawei Technologies Hansaallee 205, 40549 Dusseldorf Germany Email: Georgios.Karagiannis@huawei.com Maxim Klyus NetCracker Kozhevnicheskaya str.,7 Bldg. #1 Moscow, Russia E-mail: klyus@netcracker.com Jun Bi Tsinghua University Network Research Center, Tsinghua University Beijing 100084 P.R. China Email: junbi@tsinghua.edu.cn Liu, et al. Expires October 5, 2016 [Page 13]