Network Working GroupIndependent Submission W. LiuInternet-DraftRequest for Comments: 8328 Huawei TechnologiesIntended status:Category: Informational C. XieExpires: March 31, 2018ISSN: 2070-1721 China Telecom J. Strassner G. Karagiannis Huawei Technologies M. KlyusNetCrackerJ. Bi Tsinghua University Y. Cheng China Unicom D. Zhang Huawei TechnologiesSeptember 27, 2017 SUPA Policy-basedFebruary 2018 Policy-Based Management Frameworkdraft-liu-policy-based-management-framework-00for the Simplified Use of Policy Abstractions (SUPA) Abstract The Simplified Use of Policy Abstractions (SUPA) policy-based management framework defines base YANG data models to encodepolicy, whichpolicy. These models point to device-, technology-, and service-specific YANG data models developed elsewhere. Policy rules within an operator's environment can be used to express high-level, possiblynetwork-widenetwork-wide, policies to a network management function (within a controller, an orchestrator, or a network element). The network management function can then control the configuration and/or monitoring of network elements and services. This document describes the SUPA basic framework, itselementselements, and interfaces. Status of This Memo ThisInternet-Draftdocument issubmitted in full conformance withnot an Internet Standards Track specification; it is published for informational purposes. This is a contribution to theprovisionsRFC Series, independently ofBCP 78any other RFC stream. The RFC Editor has chosen to publish this document at its discretion andBCP 79. Internet-Draftsmakes no statement about its value for implementation or deployment. Documents approved for publication by the RFC Editor areworking documentsnot candidates for any level oftheInternetEngineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The listStandard; see Section 2 of RFC 7841. Information about the currentInternet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximumstatus ofsix monthsthis document, any errata, and how to provide feedback on it may beupdated, replaced, or obsoleted by other documentsobtained atany 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 March 31, 2018.https://www.rfc-editor.org/info/rfc8328. Copyright Notice Copyright (c)20172018 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 (https://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.Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 2.2. Abbreviations and Definitions . . . . . . . . . . . . . . 4 3. Framework for GenericPolicy-basedPolicy-Based Management . . . . . . . .45 3.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2. Operation . . . . . . . . . . . . . . . . . . . . . . . .910 3.3. The GPIM and the EPRIM . . . . . . . . . . . . . . . . . 10 3.4. Creation of Generic YANG Modules . . . . . . . . . . . . 10 4. Security Considerations . . . . . . . . . . . . . . . . . . . 11 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . .1112 6.ContributorsReferences . . . . . . . . . . . . . . . . . . . . . . . .11 7. Acknowledgements. 12 6.1. Normative References . . . . . . . . . . . . . . . . . . 12 6.2. Informative References . . .12 8. References. . . . . . . . . . . . . . 12 Acknowledgements . . . . . . . . . . .13 8.1. Normative References. . . . . . . . . . . . . 13 Contributors . . . . . . . . .13 8.2. Informative References. . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . .1514 1. Introduction Traffic flows over increasingly complex enterprise and service provider networksbecomeare becoming more and more important. Meanwhile, the rapid growth ofthethis variety makes the task of network operations and management applications deploying new services much more difficult. Moreover, network operators want to deploy new services quickly and efficiently. Two possible mechanisms for dealing with this growing difficulty are 1) the use of software abstractions to simplify the design and configuration of monitoring and controloperations,operations and 2) 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.PolicyThere is a set of policy rules within an operator's environmentare a set of rulesthatdefinedefines how services are designed, delivered, and operated. The SUPA (Simplified Use of Policy Abstractions) data model representshigh- level,a high-level, possibly network-wide policy, which can be input to a network management function (within a controller, an orchestrator, or a networkelement).Theelement). The network management function can then control the configuration and/or monitoring of network elements and services according to such policies. SUPA defines ageneric policy information modelGeneric Policy Information Model (GPIM)[I-D.ietf- supa-generic-policy-info-model][SUPA-INFO] for use in network operations and management applications. The GPIM defines concepts and terminology needed by policy management independent of the form and content of the policy rule. TheEvent-Condition-ActionEvent- Condition-Action (ECA) Policy Rule Information Model (EPRIM)[I-D.ietf-supa-generic-policyinfo-model][SUPA-INFO] extends the GPIM by defining how to build policy rules according to theevent-condition-actionECA paradigm. Both the GPIM and the EPRIM are targeted at controlling the configuration and monitoring of network elements throughout the service development and deploymentlifecycle.life cycle. The GPIM and the EPRIM can both be translated into corresponding YANG[RFC6020][RFC6020bis][RFC6020] [RFC7950] modules that define policy concepts, terminology, and rules in a generic and interoperable manner; additional YANG modules may also be derived 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. Some typical and usefulinstances,instances for authors to understand the applicability of SUPA, such as SNMP blocking upon load of link reaching athreshold,threshold and virtualmachingmatching migration upon thechanginngchanging of user location, arewrittendescribed in[I-D.cheng-supa-applicability].[SUPA-APP]. 2. Terminology 2.1. 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. 2.2. Abbreviations and Definitions SUPA: The Simplified Use of PolicyAbstractions,Abstractions isthe working group name, whicha policy-based management framework that defines a datamodel,model to be used to represent high-level, possibly network-widepolicies, whichpolicies. This data model can be input to a network management function (within a controller, an orchestrator, or a network element). YANG:anAn acronym for "Yet Another Next Generation". YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONFnotifications.[RFC6020]notifications [RFC6020] ECA:Event-Condition-Action,Event-Condition-Action is ashort-cutshortcut for referring to the structure of active rules inevent drivenevent-driven architecture and active database systems. EMS: An Element ManagementSystem,System is software used to monitor and control network elements (devices) in telecommunications. NMS: A Network ManagementSystem,System is a set of hardware and/or software tools that allow an IT professional to supervise the individual components of a network within a larger network management framework. OSS: An Operations/Operational SupportSystem, areSystem is a computersystemssystem used by telecommunications service providers to manage their networks (e.g., telephone networks). BSS: A Business SupportSystems, areSystem is used to support various end-to-end telecommunication services. GPIM: A Generic Policy InformationModel, whichModel defines concepts and terminology needed by policy management independent of the form and content of the policy rule. EPRIM: An ECA Policy Rule InformationModel, whichModel extends the GPIM by defining how to build policy rules according to theevent-condition- actionECA paradigm. GPDM: Generic Policy Data Models[I-D.ietf-supa-generic-policy-data- model],[SUPA-DATA] are created from the GPIM. These YANG data model policies are used to control the configuration of network elements that model the service(s) to be managed. The relationshipofbetween the information model (IM) andDMdata model (DM) can be founded in [RFC3444]. Declarative Policy:policiesPolicies that specify the goals to be achieved but not how to achieve those goals (also called "intent-based" policies). Please note that declarative policies are out of scope for the initial phase of SUPA. 3. Framework for GenericPolicy-basedPolicy-Based Management This section briefly describes the design and operation of the SUPA policy-based management framework. 3.1. Overview Figure 1 shows a simplified functional architecture of how SUPA is used to define policies for creating snippets of network elementconfiguration snippets. (Note from Editor: a "snippet" is a small piece of information (e.g., part of a sentence that was cut out).)configurations. 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,and/ orand/or the combination of the GPIM and the EPRIM, is converted to generic YANGdatamodules. In one possible approach (shown with asterisks in Figure 1), SUPA Generic Policy and SUPA ECA Policy YANGdatamodules together with the Resource and Service YANG data models specified in the 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, and the policies input by operators are then translatedtointo configuration snippets. Note that the Resource and Service YANG data models may not exist. In this case, the SUPA generic policy YANGdatamodules serve as an extensible basis to develop new YANG data models for the Service InterfaceLogicLogic. This transfers the work specified by the Resource and Service YANG data models specified in the IETF into the Service Interface Logic. +---------------------+ +----------+ \| SUPA | | IETF |---+----+ Information Models | +----------+ | /| GPIM and EPRIM | | +---------+-----------+ Assignments | | Defines Policy Concepts andManageManaged | \|/ Content | +---------+-----------+ | \| SUPA Generic | +----+ & ECA Policy | /| YANGDatamodules | +---------+-----------+ * Possible Approach +-----------------------------*-----------------------------+ | Management System * | | \*/ | | Fills +---------+---------+ +-------------+ | | +--------+ Forms \| Service Interface |/ |Resource and |/ | +----+ | |Operator|--------+ Logic +--|Service YANG |----|IETF| | +--------+ Runs /| (locally defined |\ |Data Modelsdata models |\ | +----+ | scripts |forms, scripts,...)| +-------------+ | | +---------+---------+ | | \|/ | | +-------+--------+ | | | Local Devices | | | | and Management | | | | Systems | | | +----------------+ | +-----------------------------------------------------------+ Figure 1: SUPA Framework Figure 1is exemplary.shows the SUPA Framework at a high level of abstraction. TheOperatoroperator actor 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 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. This type of policy explicitly defines the current and desired states of the system being managed. Imperative policy rules require additional management functions, which are explained insection 3.2 below.Section 3.2. Figure 2 shows how the SUPA Policy Model is used to create policy data modelsstep by stepstep-by-step and how the policy rules are used to communicate among various network management functions located on different layers. TheGeneric Policy Information Model (GPIM)GPIM is used to construct policies. The GPIM defines generic policyconcepts,concepts as well as two types of policies: ECA policy rules and declarative policy statements. A set of Generic Policy Data Models (GPDM) 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. Resource and Service YANG Data Models:modelsModels of the service as well as 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. | SUPA Policy Model | | +----------------------------------+ | | Generic Policy Information Model | | +----------------------------------+ | D D | D +-------------v-------------+ +----------------------+ | D | ECA Policy Rule | | OSS/BSS/Orchestrator <--+ | D | Information Model | +----------^-----------+ | | D +---------------------------+ C | | D D C | | +----+D+------------------------+D+---+ C +-----+ D SUPA Policy Data Model D | +----------v-----------+ | | ----v-----------------------+ D | | EMS/NMS/Controller <--------+ | Generic Policy Data Model | D | +----------^-----------+ | | ----------------------------+ D | C +-----+ D D | C | | | +---------v-----------------v--+ | +----------v-----------+ | | | | ECA Policy Rule Data Model | | | Network Element <--+ | | +------------------------------+ | +----------------------+ | +-------------------------------------+ | |Figure 2: SUPA Policy Model Framework In Figure 2:Legend: The double-headed arrow with Csmeans communication;= "communication" The arrow with Dsmeans derived from. The components within this framework are:= "derived from" Figure 2: SUPA Policy Model Framework SUPA Policy Model: This model represents one or more policy modules that contain the following entities: Generic Policy Information Model:aA model for defining policy rules that are independent of data repository, data definition, query, implementationlanguages,language, 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:aA model of policy rules that are dependent on data repository, data definition, query, implementationlanguages,language, and protocol. ECA Policy Rule Information Model (EPRIM): This model represents a policy rule as a statement that consists of an event clause, a condition clause, and an action clause. This type ofPolicy Rulepolicy 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:aA model of policy rules, derived from EPRIM,whilewhere each policy rule consists of an event clause, a condition clause, and an action clause. EMS/NMS/Controller: This 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 ofNetwork Elements).network elements). Network Element(NE), which(NE): An element that can interact with the local or remote EMS/NMS/Controller in order to exchange information, such as configuration information,policy enforcementpolicy-enforcement capabilities, and network status.Relationship betweenRelationships among Policy,ServiceService, and Resource modelscan beare illustratedby the figure below.in Figure 3. +---------------+ +----------------+ | Policy | (1) | Service | | |*******************| | | ( SUPA ) |*******************| ( L3SM, ... ) | +---------------+ +----------------+ ** /*\ ** * ** * (2) ** * (3) ** * ** * ** * +-------------------+ | Resource | | | | (Inventory, ... ) | +-------------------+ Figure 3: Relationshipbetweenamong Policy,ServiceService, and ResourcemodelsModels In Figure 3: (1) The policy manages and can adjust service behavior as necessary (1:1..n). In addition, data from resources and services are used to select and/or modify policies during runtime. (2) The policy manages and can adjust resource behavior as necessary(1:1..n)(1:1..n). (3)resourceResource hosts service; changing resources may change service behavior asnecessarynecessary. Policies are used to control the management of resources and services, while data from resources and services are used to select and/or modify policies during runtime. More importantly, policies can be used to manage how resources are allocated and assigned to services. This enables a single policy to manage one or multiple services and resources as well as their dependencies. The use of (1:1..n) in point (1) and (2)below figure 3above show that one policy rule is able tomanagesmanage and can adjust one or multiple services/resources.LineLines (1) and (2)connecting(connecting policy to resource and policy toserviceservice) are the same, and line (3)connecting(connecting resource toserviceservice) is different as it's navigable only from resource to service. 3.2. Operation SUPA can be used to define various types of policies, including policies that affect services and/or the configuration of individual network elements 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. The SUPA scope is limited to policy information and data models. SUPA does not define network resource data models or network service data models; both are out of scope. Instead, SUPA makes use of network resource data models defined by otherWGsworking groups orSDOs.Standards Development Organizations (SDOs). Declarative policies are out of scope for the initial phase of SUPA. 3.3. The GPIM and the EPRIM The GPIM provides acommonshared vocabulary for representing concepts that are common to different types ofpolicy,policies, but which are independent of language, protocol, repository, and level of abstraction. Hence, the GPIM defines concepts and vocabulary needed by policy management systems independent of the form and content of the policy. The EPRIM is a more specific model that refines the GPIM to specify policy rules in anevent-condition-actionECA form. This enables different policies at different levels of abstraction to form a continuum, where more abstract policies can be translated into more concretepolicies,policies andvice-versa.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. 3.4. 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 and the combination of the GPIM and theEPRIM,EPRIM are translatedtointo 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 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 apolicy, and as well,policy; it will also specify an extension for defining policy rules according to the ECAparadigm.(Note from Editor:paradigm. (Note: This means that policies can be defined using the GPIM directly, or using the combination of the GPIM and the EPRIM. If you use only the GPIM, you get a technology- and vendor- independent information model that you are free to map to the data model of your choice; note that the structure of a policy is NOT defined. If you use the GPIM and the EPRIM, you get a technology- and vendor-independent information model that defines policies as anevent-condition-actionECA policy rule (i.e.,imperative) rule.)imperative).) The process of developing the GPIM,EPRIM andthederived/translatedEPRIM, and the derived/ translated YANG data models is realized following the sequence shown below. After completing this processandand, 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;Where: (1)=GPIM (2)=EPRIM (3)=YANG datamodels; (4)= Implementation; (3')= updatemodels (4)=Implementation (3')=update of YANG datamodels;models (2')=update ofEPRIM; (1') = updateEPRIM (1')=update of GPIM The YANG module derived from the GPIM contains concepts and terminology for the common operation and administration of policy- basedsystems,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 by representing policies using anevent-condition-actionECA structure. The above sequence allows for the addition ofnew,new model elements, as well as the editing of existingmodel elementsones, in the GPIM and EPRIM. In practice, the implementation sequence may be much simpler. Specifically, it is unlikely that the GPIM will need to be changed. In addition, changes to the EPRIM will likely be focused on fine- tuning the behavior offered by a specific set of model elements. 4. Security Considerations This informational document presents the framework and workflow ofSUPA,SUPA as well as an explanation on the relationship of policy, service and resources. This document does not introduce any new security issues, and the framework has no security impact on the Internet. The same considerations are relevant as those for the base NETCONF protocol (see Section 9 in [RFC6241]). 5. IANA Considerations This document has noactions for IANA.IANA actions. 6.Contributors The following people all contributedReferences 6.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs tocreating this document, listedIndicate 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 inalphabetical order: Ying Chen, China Unicom Luis M. Contreras, Telefonica I+D Dan Romascanu, Avaya Juergen Schoenwaelder, Jacobs University, Germany Qiong Sun, China Telecom 7. Acknowledgements This document has benefited from reviews, suggestions, commentsRFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <https://www.rfc-editor.org/info/rfc8174>. 6.2. Informative References [RFC3444] Pras, A. andproposed text provided by the following members, listed in alphabetical order: Andy Bierman, Marc Blanchet, Benoit Claise, Joel Halpern, Jonathan Hansford, Diego R. Lopez, Johannes Merkle, Gunter Wang, Yangyang Wang, Bert Wijnen, Tianran Zhou. Part ofJ. Schoenwaelder, "On theinitial draft of this document was picked up from previous documents,Difference between Information Models andthis section listsData Models", RFC 3444, DOI 10.17487/RFC3444, January 2003, <https://www.rfc-editor.org/info/rfc3444>. [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for theacknowledgements from them. From "SUPA Value Proposition" [I-D.klyus-supa-value-proposition] 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 JuergenNetwork Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, <https://www.rfc-editor.org/info/rfc6020>. [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., 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. SaperiaJ., Ed., andC. Zhou. The authors of "SUPA Value Proposition" [I-D.klyus-supa-value- proposition] 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)" [I-D.karagiannis-supa-problem-statement] 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. 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)" [I-D.karagiannis-supa-problem-statement] 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)" [I-D.zhou-supa-framework] 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. The authors ofA. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, <https://www.rfc-editor.org/info/rfc6241>. [RFC7950] Bjorklund, M., Ed., "TheFramework of Simplified Use of Policy Abstractions (SUPA)" [I-D.zhou-supa-framework] were: Cathy Zhou, Huawei Technologies Luis M. Contreras, Telefonica Qiong Sun, China Telecom Parviz Yegani, Juniper 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14,YANG 1.1 Data Modeling Language", RFC2119,7950, DOI10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/info/rfc2119>. 8.2. Informative References [I-D.cheng-supa-applicability]10.17487/RFC7950, August 2016, <https://www.rfc-editor.org/info/rfc7950>. [SUPA-APP] Cheng, Y., Liu, D., Fu, B., Zhang, D., and N. Vadrevu, "Applicability of SUPA",draft-cheng-supa-applicability-01 (workWork inprogress),Progress, draft-cheng- supa-applicability-01, March 2017.[I-D.ietf-supa-generic-policy-data-model][SUPA-DATA] Halpern,J. and J.J., Strassner, J., and S. Van der Meer, "Generic Policy Data Model for Simplified Use of Policy Abstractions (SUPA)",draft- ietf-supa-generic-policy-data-model-04 (workWork inprogress),Progress, draft-ietf-supa- generic-policy-data-model-04, June 2017.[I-D.ietf-supa-generic-policy-info-model][SUPA-FRAME] Zhou, C., Contreras, L., Sun, Q., and P. Yegani, "The Framework of Simplified Use of Policy Abstractions (SUPA)", Work in Progress, draft-zhou-supa-framework-02, May 2015. [SUPA-INFO] Strassner, J., Halpern, J., and S. Meer, "Generic Policy Information Model for Simplified Use of Policy Abstractions (SUPA)",draft-ietf-supa-generic-policy-info- model-03 (workWork inprogress),Progress, draft-ietf-supa- generic-policy-info-model-03, May 2017.[I-D.karagiannis-supa-problem-statement][SUPA-STATE] Karagiannis, G., Strassner, J.,Qiong,Sun, Q., Contreras, L., Yegani, P., and J. Bi, "Problem Statement for Simplified Use of Policy Abstractions (SUPA)",draft-karagiannis- supa-problem-statement-07 (workWork inprogress),Progress, draft-karagiannis-supa-problem-statement-07, June 2015.[I-D.klyus-supa-value-proposition][SUPA-VALUE] Klyus, M., Strassner, J.,(Will), S.,Liu, W., Karagiannis, G., and J. Bi, "SUPA Value Proposition",draft-klyus-supa-value- proposition-00 (workWork in Progress, draft- klyus-supa-value-proposition-00, March 2016. Acknowledgements This document has benefited from reviews, suggestions, comments, and proposed text provided by the following members, listed inprogress), March 2016. [I-D.zhou-supa-framework] Zhou, C., Contreras, L., Qiong, Q.,alphabetical order: Andy Bierman, Marc Blanchet, Mohamed Boucadair, Scott O. Bradner, Scott Cadzow, Zhen Cao, Vikram Choudhary, Benoit Claise, Spencer Dawkins, Mehmet Ersue, Ian Farrer, Fernando Gont, Joel Halpern, Jonathan Hansford, Jing Huang, Xing Li, Marco Liebsch, Diego R. Lopez, Johannes Merkle, Marie-Jose Montpetit, Kostas Pentikousis, Simon Perreault, Hosnieh Rafiee, Raghav Rao, Jose Saldana, Jon Saperia, Tom Taylor, Jean Francois Tremblay, Tina Tsou, Eric Voit, Gunter Wang, Yangyang Wang, Bert Wijnen, andP. Yegani, "The FrameworkTianran Zhou. Part ofSimplified Usethe initial draft ofPolicy Abstractions (SUPA)", draft-zhou-supa-framework-02 (work in progress), May 2015. [RFC3198] Westerinen, A., Schnizlein, J., Strassner, J., Scherling, M., Quinn, B., Herzog, S., Huynh, A., Carlson, M., Perry, J., and S. Waldbusser, "Terminology for Policy-Based Management", RFC 3198, DOI 10.17487/RFC3198, November 2001, <https://www.rfc-editor.org/info/rfc3198>. [RFC3444] Pras, A. and J. Schoenwaelder, "Onthis document was picked up from previous documents: [SUPA-VALUE], [SUPA-STATE], and [SUPA-FRAME]. We appreciatively acknowledge theDifference between Information Modelsauthors, contributors, andData Models", RFC 3444, DOI 10.17487/RFC3444, January 2003, <https://www.rfc-editor.org/info/rfc3444>. [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language foracknowledged parties of those documents. Contributors The following people contributed to theNetwork Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, <https://www.rfc-editor.org/info/rfc6020>. [RFC6241] Enns, R., Ed., Bjorklund, M., Ed.,creation of this document, listed in alphabetical order: Luis M. Contreras, Telefonica I+D Dan Romascanu, Avaya Juergen Schoenwaelder,J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, <https://www.rfc-editor.org/info/rfc6241>. [RFC7285] Alimi, R., Ed., Penno, R., Ed., Yang, Y., Ed., Kiesel, S., Previdi, S., Roome, W., Shalunov, S., and R. Woundy, "Application-Layer Traffic Optimization (ALTO) Protocol", RFC 7285, DOI 10.17487/RFC7285, September 2014, <https://www.rfc-editor.org/info/rfc7285>. [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, <https://www.rfc-editor.org/info/rfc7950>.Jacobs University, Germany Qiong Sun, China Telecom Parviz Yegani, Huawei Technologies Cathy Zhou, Huawei Technologies Authors' AddressesWill(Shucheng)Will (Shucheng) Liu Huawei Technologies Bantian, Longgang District Shenzhen 518129 China Email: liushucheng@huawei.com Chongfeng Xie China Telecom China Telecom Information Technology Innovation Park Beijing 102209 China Email: xiechf.bri@chinatelecom.cn John Strassner Huawei Technologies 2330 Central Expressway SantaClara 95138Clara, CAUSA95138 United States of America Email: john.sc.strassner@huawei.com Georgios Karagiannis Huawei Technologies Hansaallee 205 Dusseldorf 40549 Germany Email: Georgios.Karagiannis@huawei.com Maxim KlyusNetCracker Kozhevnicheskaya str.,7 Bldg. #1 Moscow RussiaEmail:klyus@netcracker.comxmaruto@gmail.com Jun Bi Tsinghua University Network Research Center, Tsinghua University Beijing 100084 China Email: junbi@tsinghua.edu.cn Ying Cheng China Unicom No.21 Financial Street, XiCheng District Beijing 100033 China Email: chengying10@chinaunicom.cn Dacheng Zhang Huawei Technologies Beijing China Email: dacheng.zhang@huawei.com