Internet DRAFT - draft-liu-supa-policy-based-management-framework
draft-liu-supa-policy-based-management-framework
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
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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
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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.
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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
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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 | |
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| 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:
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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.
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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
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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.
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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.
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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.
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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
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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
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