Network Working Group C. Zhou
Internet-Draft T. Tsou
Intended status: Informational Huawei Technologies
Expires: January 21, 2015 D. Lopez
Telefonica
G. Karagiannis
University of Twente
Q. Sun
China Telecom
July 21, 2014
The Architecture for Application-based Policy On Network Functions
draft-zhou-aponf-architecture-03
Abstract
Currently, there are network management applications that present
specific demands on a communication network. This document describes
the APONF basic architecture, its elements and interfaces. The main
APONF architecture entities are the Network Management Application
Agent (NMAA), which is a network entity that creates and runs network
services, and Application-based Policy Decision (ABPD), which
supports classified application models. Each of these models support
application demands that are similar in nature and therefore can be
grouped/classified together. Moreover, the ABPD maps the classified
application models into network capabilities, e.g., network
management and controlling policies.
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 January 21, 2015.
Copyright Notice
Copyright (c) 2014 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.
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(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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described in the Simplified BSD License.
Requirements Language
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 RFC 2119 [RFC2119].
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Overview of the APONF Architecture . . . . . . . . . . . . . 3
4. Network Management Applications . . . . . . . . . . . . . . . 5
4.1. Network Management Application Agent (NMAA) . . . . . . . 5
5. Application Based Policy Decision . . . . . . . . . . . . . . 7
6. Network Elements . . . . . . . . . . . . . . . . . . . . . . 10
7. The APONF Interface . . . . . . . . . . . . . . . . . . . . . 10
8. Security Considerations . . . . . . . . . . . . . . . . . . . 10
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10
11. Normative References . . . . . . . . . . . . . . . . . . . . 11
12. Informative References . . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
As the Internet grows, more and more new services keep on arising,
and network traffic is rapidly increased, which may result in slow
performance of network devices (e.g., BRAS) and poor end-user
experience. In addition, especially for cloud applications, the
cloud tenants and developers usually need to use the communication
network capabilities, such as dynamic network management and dynamic
traffic steering, easily, accurately and efficiently. In this way,
the deployment of new applications and services may be accelerated
and the user experience can be improved.
In particular, today network operators are challenged to create an
abstract view of their network infrastructure and help service
developers on using and programming this abstraction rather than
manipulating individual devices. In this context, network management
applications can be used to provide the required configuration and
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application programming interfaces to such service developers.
Subsequently, a network management application can use the
application based demands and possibly update its associated network
service graph A network service graph provides an abstraction view of
a network infrastructure, which also includes network service
attributes. The network service attributes are network management
application dependent which may include the network service
dependencies and network configuration and topology used by a network
management application, the used flow steering policy, the IPv6
transition policy, the Distributed Data Center application policy.
Network management applications are Operational Support System (OSS)
like applications that help a communication service provider to
monitor, control, analyze and manage a communication network.
For each network service instance a network service graph needs to be
generated and maintained.
The up to date network service graph needs to (1) be communicated
between the network management application systems and the network
management and controlling systems, (2) map the attributes of the
network service graph into specific network management policies,
i.e., device level configuration models.
The main goal of this document is to specify the APONF basic
architecture, its elements and interfaces. The main APONF
architecture entities are the Network Management Application Agent
(NMAA) and the Application-based Policy Decision (ABPD). NMAA is a
network entity that creates and runs network services and is able to
use the application based demands and possibly update their
associated network service graph. The ABPD is able to map the
network service graphs into specific network management policies,
i.e., device level configuration models. The definition of these
network management policies is out of the APONF scope.
2. Terminology
The terminology used in the APONF problem statement draft
[ID.karagiannis-aponf-problem-statement] applies also to this draft.
3. Overview of the APONF Architecture
This section depicts an overview of the architecture of application-
based policy on network functions. Figure 1 shows APONF
architecture. The basic components of the APONF architecture are:
Network Management Application: Operational Support System (OSS) like
applications that help a communication service provider to monitor,
control, analyze and manage a communication network. Several network
management applications MAY communicate with the Application Based
Policy Decision block via the Network Management Application Agent.
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+---------------------------------+ +------------------------- ----+
| Network Management Application | |Network Management Application|
| | | |
| | | |
| +---------------------+ | | +---------------------+ |
| | Network Management | | | | Network Management | |
| | Application Agent | |... | | Application Agent | |
| | | | | | | |
| | (NMAA) | | | | (NMAA) | |
| +------------+--------+ | | +---------+-----------+ |
| | | | | |
| | | | | |
+----------------|----------------+ +-------------|----------------+
| |
| |
+---------------|------------------------------------|----------------+
|+--------------v-------------+ +---+ +--------v-------------------+|
||Classified Application Model| |...| |Classified Application Model||
|+----------------------------+ +---+ +----------------------------+|
| |
| Application Based Policy Decision (ABPD) |
+-----------------------------------^--------------------------------+
|
|
|
+--------------------+---------------------+
| |
| |
| |
+-------------v---------------+ +------------v-------------+
| | | |
| | ... | |
| Network Element | | Network Element |
+-----------------------------+ +--------------------------+
Figure 1: Architecture of application-based policy on network
functions
The Network Management Application Agent (NMAA): a network entity
that creates and runs network services. These network services
should be developed by an operator, which in the context of APONF are
assumed to be already available.
The NMAA is able to generate, for each of these network service
Instances, and using application based demands a network service
graph.
Application Based Policy Decision(ABPD): A network entity which
provides an interface to NMAA(s) and is able to map the classified
application based models, which are including the classified
application based demands and the network service graph, into
specific network management policies, i.e., device level
configuration models, which are used by the communication network.
ABPD can communicate with multiple NMAAs simultaneously.
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Network Element (NE):handles incoming packets based on the ABDP
network management policies and the corresponding network management
and controlling procedures.
Figure 1 shows the basic architecture of application-based policy on
network functions.
4. Network Management Applications
This architecture is expected to be used for several categories of
network management applications. Such network management
applications are representing the realizations of the APONF use
cases, which are: "Distributed Data Center "
[ID.draft-cheng-aponf-ddc-use-cases], "IPv6 transition "
[ID.draft-sun-aponf-openv6-use-cases],
"Virtualized Enterprise Applications "
[ID.draft-huang-aponf-use-cases] , "Source Address Validation and
Traceback (SAVI)" [ID.draft-bi-aponf-sdsavi], and "Using the abstract
view of network by service developers"
[ID.draft-liu-aponf-using-abstract-view-use-case].
These network management applications are represented by a set of
network services. Each network service can be represented by a
classified application based policy model, since it can model the
group of demands coming from a bundle of end user applications that
impose similar requirements on the communication network. Such
network services can be "Distributed Data Center ", " IPv6
transition", "Virtualized Enterprise Applications " and "Source
Address Validation and Traceback (SAVI) " and "Using the abstract
view of network by service developers". For each network service
instance a network service graph needs to be generated and
maintained.
4.1. Network Management Application Agent (NMAA)
The NMAA is part of the network management application and is a
network entity that creates and runs network services. These network
services should be developed by an operator, which in the context of
APONF are assumed to be already available.
The assumption here is that the network management application has a
complete view of the available network and network capabilities that
it can use. Moreover, it is assumed that the network management
application is able to have the abstract view of the network and on
how the network service is mapped into this abstract view. This
network abstract view is defined using the network service graph . It
is assumed that the NMAA can create and maintain the network service
graph.
An NMAA is a typical OSS gateway or Network Management Station
entity, that needs to support the following new functional blocks as
shown in Figure 2:
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+----------------------------------------------+
|NMAA |
| |
| +--------------+ +----------------+ |
| | | | Create/Update | |
| | Typical OSS | |network service | |
| | | | graph | |
| +--------------+ +----------------+ |
| |
| |
| |
| +--------------+ +-----------------+ |
| | End User | |NMAA - ABDP | |
| | Application | | | |
| | Interaction | | Interface | |
| +--------------+ +-----------------+ |
+----------------------------------------------+
Figure 2: NMAA Functionality Block Diagram
o Typical OSS (Operations Support System) features.
o Create/Update network service graphs: this is a NMAA functional
block and is used by the NMAA to use the network service
description and create or update a network service graph.
The assumption used here is that the description of the network
services is provided to end user applications in such a way that
the end user application developer can use and program certain
network capabilities such that the end user QoE can significantly
be increased. The modified versions of the network service
description are made known to the network management application
and NMAA. This event initiates the update of the network service
graph.
o End User Application Interaction: this functional block is used to
provide and receive information to/from the end user application
engine. This functional block is in charge to provide the
description of the network services to end user applications in
such a way that the end user application developer can use and
program certain network capabilities such that the end user QoE
can significantly be increased. This functional block is also used
to receive the modified versions of the network service from the
end user application and to inform the "Create/Update network
service graph" functional block about this change. This event
initiates the update of the network service graph. Note that it is
assumed that the realization of this functional block and the
interface with the end user are out of the APONF's scope.
o "NMAA - ABDP interface": this functional block is used to support
a signaling protocol used between NMAA and the ABDP. Note that
one candidate IETF protocol that can be used for this purpose
is an enhanced version of the IETF Network Configuration Protocol
(NETCONF) [RFC6241].
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The Network Management Application Agent (NMAA) will use the APONF
interface to communicate with the Application Based Policy Decision
(ABPD) entity.
5. Application Based Policy Decision
The Application-Based Policy Decision (ABPD) block, is a an entity
used between the Network Management Applications and the network
elements to provide and maintain the application based policies. It
supports the APONF interface/protocol and is a software repository,
which stores the information associated with each NE, and maps the
classified application models, i.e., application based demands and
the network service graph, into existing network management policies,
i.e., device configuration models. In particular, by creating
application based policies that mirror application semantics, a
better mapping to existing network management policies can be
realized. This provides a simple, self-documenting mechanism for
capturing application-based policy requirements and mapping them to
existing network management policies. This will allow applications
to use the network capabilities in a more accurate and efficient way.
Figure 3 illustrates the ABPD functionality block diagram, which is
based on [ID.farrkingel-pce-abno-architecture] and enhanced to
satisfy the demands of the APONF use cases. Note that the realization
of the functional blocks defined in
[ID.farrkingel-pce-abno-architecture] is out of the scope of APONF.
However, the capabilities provided by the "Provisioning manager"
functional block can be combined with capabilities provided by the
APONF defined "ABPD Network Management Interface" functional block.
The Application Based Policy Decision (ABPD) block includes all the
functional blocks provided in Figure 1 of
[ID.farrkingel-pce-abno-architecture], together with the following
new defined functional blocks:
o Fresh network service graphs Maintenance: maintains a fresh
abstract view of the network. Note that this is realized using
the network service graph that is created by the NMAA. Important
to note that for each network service / classified application
model that is managed by a network management application a
different network service graph is needed. So in order to support
this capability, the APONF architecture needs to support a
functional block that stores all these abstract views of the
network in different network service graphs that are identified by
an unique ID.
o Application to Network Mapping: the following features are
supported by this functional block:
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1. Translates the actions and the changed network service graph
received from the network management application, see
explanation below, to a new network service graph. This is
accomplished by using application based demands generated by
network management applications systems to map the network
service graph into specific network management policies,
i.e., into device level configuration models. Such
application based demands are:
+----------------------------------------------------------------+
|ABPD Block |
| +--------------------------+ |
| | ABPD Management Interface| |
| +------------+-------------+ |
| +--------------+ | +---------------++--------------+ |
| | ABPD-NMAA | | | Fresh network ||Application to| |
| | | | | || Network | |
| | | | | || Mapping | |
| | | | | || | |
| | | | | || | |
| | Interface | | | Maintenance || | |
| +-----------+--+ | +------+--------++-+------------+ |
| | | | | |
| | | | | |
| +-+----+------+------------+-+ |
| +------+ | | +-------+ |
| |Policy+--+ ABPD Controller +-----+ | |
| |Agent | | +--+ | OAM | |
| +-+--+-+ +-+------------+----------+--+ | |Handler| |
| | | | | | | | | |
| +-----++ | +----+-+ +-------+-------+ | | +-------+ |
| |ALTO | +-+ VNTM |--+ | | | |
| |Server| +--+-+-+ | | | +---+--------+ |
| +--+---+ | | | PCE | | |I2RS client | |
| | +-------+ | | | | | | |
| | | | | | | +------------+ |
| +------+--+-+ | | | | |
| | Databases +-------:----+ | | |
| | TED | | +-+---+----+----+ | |
| | LSP-DB + | | | | | |
| +-----+--+--+ +-+---------------+-------+-+ |
| | Provisioning Manager | |
| +---------------------------+ |
+----------------------------------------------------------------+
Figure 3: ABPD Functionality Block Diagram, based on
[ID.farrkingel-pce-abno-architecture].
Encapsulating, de-encapsulating packets associated with a
flow into a tunnel (for example, VPN service, IPv6
transition service demands on the network).
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Blocking, or dropping packets associated with a flow in
(the edge of) the network element when the network security
service is aware of the attack (for example, SAVI service,
Anti-DoS service demands on the network).
Configure and dynamically reconfigure data centers to the
steer and reroute traffic associated with a specific flow.
Configure and dynamically reconfigure data centers to
change priorities of different types of traffic associated
with a specific flow.
Logging the traffic associated with a flow for network
security service,
Optimization of the traffic based on the IETF ALTO
[ID.draft-ietf-alto-protocol],
Other actions defined by the administrator.
2. if required updates all databases, see Section 2.3.1.8 of
[ID.farrkingel-pce-abno-architecture].
3. Uses existing network management and signaling protocols, i2rs
[I2RS], SFC [SFC], NETCONF [NETCONF], etc., to request
the implementation of the changes into the network.
o ABPD Network Management Interface: this functional block provides
the interface with existing network management, i2rs,
NETCONF, etc. protocols to request and negotiate the
implementation of the changes into the network configuration.
o ABPD -NMAA interface: this functional block is used to support the
communication between NMAA and the ABDP. Note that a candidate
IETF protocol that can be used for the support of this
interface is an enhanced For example, a possible protocol that
can be enhanced and used is the Network Configuration Protocol
(NETCONF) [RFC6241].
The definition of the network management policies is out of the APONF
scope.
These application-based policy models can meet the application's
demands on the communication network and map these demands to network
management policies that can be understood by the communication
network.
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6. Network Elements
The Network Element (NE) handles incoming packets based on the policy
information communicated with the ABPD block and makes corresponding
policy enforcement, which is based on existing network management
policies, see Section 5.
A NE may be a physical entity or a virtual entity and is locally
managed, whether via CLI, SNMP, or NeTConf. Examples of NEs can
include:
o A router that has an extended function module. The extended
module handles incoming packets based on the flow table of the
module.
o A server that runs vRouter or vSwitch.
o A CGN that runs NAT, Tunnel En/De-capsulation functions.
o A virtual network function entity.
7. The APONF Interface
This APONF Interface/Protocol, needs to be specified by the APONF
effort and is used to support the communication between the NMAA
entity and the ABPD entity. Several IETF protocols can be used
for this purpose.
A gap analysis is being performed in order to identify and select the
IETF protocol that, after extension, can enable the streaming
transfer of bulk-variable/data of the up to date network service
graphs between network management application systems and the network
management and controlling systems.
For example, a possible protocol that can be enhanced and used is the
Network Configuration Protocol (NETCONF) [RFC6241].
8. Security Considerations
Security is a key aspect of any protocol that allows state
installation and extracting of detailed configuration states. More
investigation remains to fully define the security requirements, such
as authorization and authentication levels.
9. IANA Considerations
No IANA considerations.
10. Acknowledgements
The authors of this draft would like to thank the following persons
for the provided valuable feedback: 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.
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Special thanks are expressed to the authors of the ID
[ID.farrkingel-pce-abno-architecture], since a significant part of
the ABPD functional blocks are based on the architecture described in
[ID.farrkingel-pce-abno-architecture].
11. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
12. Informative References
[I2RS] Interface to the Routing System (i2rs) charter,
http://datatracker.ietf.org/wg/i2rs/charter/
[ID.draft-ietf-alto-protocol] R. Alimi, R. Penno, Y. Yang, "ALTO
Protocol", IETF Internet draft (work in progress), draft-ietf-alto-
protocol-27, March 2014
[ID.farrkingel-pce-abno-architecture] King, D. and A. Farrel,
"A PCE-based Architecture for Application-based Network Operations",
Feb 2014.
[ID.karagiannis-aponf-problem-statement] G. Karagiannis, W. Liu,
T. Tsou, Q. Sun, and D. Lopez,"Problem Statement for Application
Policy on Network Functions (APONF)(work in progress)", June 2014.
[ID.draft-sun-aponf-openv6-use-cases] C. Xie, Q. Sun, JF. Tremblay,
"Use case of IPv6 transition in APONF", IETF Internet draft
Work in progress), draft-sun-aponf-openv6-use-cases-00, July 2014
[ID.draft-cheng-aponf-ddc-use-cases] Y. Cheng, C. Zhou,
G. Karagiannis, JF. Tremblay, "Use Cases for Distributed Data Center
Applicatinos in APONF", IETF Internet draft (Work in progress),
draft-cheng-aponf-ddc-use-cases-00, July 4, 2014
[ID.draft-huang-aponf-use-cases] C. Huang, Jiafeng Zhu, Peng He,
Shucheng (Will) Liu, G. Karagiannis, "Use Cases on Application-
centric Network Management and Service Provision" IETF Internet draft
(Work in progress), draft-huang-aponf-use-cases-01, Juy 2014
[ID.draft-liu-aponf-using-abstract-view-use-case] W. Liu, T. Tsou,
G. Karagiannis, J. Saldana, "APONF Use Case: Using Abstract View of
Network by Application Developers", IETF Internet draft (Work in
progress), draft-liu-aponf-using-abstract-view-use-case-00,
July 4, 2014
[ID.draft-bi-aponf-sdsavi] J. Bi, G. Yao, "Software Defined SAVI",
IETF Internet draft (Work in progress),
draft-bi-aponf-sdsavi-00, July 4, 2014
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[NETCONF] Network Configuration (netconf) charter,
http://datatracker.ietf.org/wg/netconf/charter/
[RFC6241] R. Enns, M. Bjorklund, J. Schoenwaelder, A. Bierman,
"Network Configuration Protocol (NETCONF)", RFC 6241, June 2011.
[SFC] IETF SFC (Service Function Chaining) WG charter,
http://datatracker.ietf.org/wg/sfc/charter/
Authors' Addresses
Cathy Zhou
Huawei Technologies
Bantian, Longgang District
Shenzhen 518129
P.R. China
Email: cathy.zhou@huawei.com
Tina Tsou
Huawei Technologies
Bantian, Longgang District
Shenzhen 518129
P.R. China
Email: Tina.Tsou.Zouting@huawei.com
Diego Lopez
Telefonica
Email: diego@tid.es
Georgios Karagiannis
University of Twente
Email: g.karagiannis@utwente.nl
Qiong Sun
China Telecom
No.118 Xizhimennei street, Xicheng District
Beijing 100035
P.R. China
Email: sunqiong@ctbri.com.cn
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