Network Working Group                                     G. Karagiannis
Internet-Draft                                      University of Twente
Intended status: Informational                                    W. Liu
Expires: December 30, 2014                                       T. Tsou
                                                     Huawei Technologies
                                                                  Q. Sun
                                                           China Telecom
                                                                D. Lopez
                                                              Telefonica
                                                           June 30, 2014


   Problem Statement for Application Policy on Network Functions (APONF)
                  draft-karagiannis-aponf-problem-statement-01

Abstract

   As more and more modern network management applications grow in scale
   and complexity, their demands and requirements on the supporting
   communication network will increase.
   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
   application programming interfaces to such service developers. The
   main goal of APONF is to (1) communicate the up to date abstract view
   of the network between the network management application systems and
   network management and controlling systems and (2) map the abstract
   view of the network into specific network management policies, i.e.,
   device level configuration models.


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
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   This Internet-Draft will expire on December 30, 2014.

Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.



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   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.

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 . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
   4.  Requirements/Objectives . . . . . . . . . . . . . . . . . . . . 7
   5   Relationships between APONF and other IETF Working Groups . . . 7
   6.  Existing Protocols and Methods . . . . . . . . . . . . . . . .  8
   7.  Security Considerations . . . . . . . . . . . . . . . . . . . . 9
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   9
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10




1.  Introduction

   Today, 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. This also implies that demands and requirements of such
   new services on the supporting communication network will increase.

   Furthermore, and especially for cloud applications, the cloud tenants
   and developers usually need to use the communication network
   capabilities, such as dynamic network management easily, accurately
   and efficiently. In this way, the deployment of new applications and
   services may be accelerated and the user experience can be improved.

   Moreover, the Development Operations (DevOps), see e.g., [DevOps], is
   another network development trend which orchestrates the complex
   interdependent processes associated with software development and
   IT operations in order to accelerate the production and roll out of
   software products and services.


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   Currently, the separation of development and operation of network
   technologies leads to slow deployment of network functions/devices
   and poor user experiences. The communication network needs to provide
   graceful adjustment capabilities in order to accommodate the diverse
   needs of applications and the rapid network evolution.

   In addition, 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. An abstract view of a network
   infrastructure can be realized using a network configuration model,
   that provides a declarative configuration and a network topology
   model that describes a multi-layer network. 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.

   In this context, network management applications can be used to
   provide the required configuration and application programming
   interfaces to such service developers. Subsequently, a network
   management application can use the application based demands and
   possibly update its associated network configuration and/or network
   topology model. Examples of network management applications that can
   modify the network configuration and/or network topology models are
   for example, Distributed Data Center Application and IPv6
   transitions, need to change the network infrastructure configuration.

   The up to date network configuration and network topology model needs
   to (1) be communicated to e.g., the network management and
   controlling systems, (2) map the network configuration and network
   topology models into specific device level configuration models.

   Currently, there are no IETF standard mechanisms or modeling
   languages that can directly be applied to model the network
   configuration nor the network topology. IETF has however, created the
   IETF SFC WG [SFC] to document a new approach to service delivery and
   operation, where one of its goals is to realize an abstract view of a
   network by using a service graph instance denoted as the Service
   Function Path (SFP). This will enable the development of suitable
   models for network configuration and network topology.

   Furthermore, there are currently no IETF solutions that can be used
   to provide the necessary configuration interfaces to service
   developers to program the abstract view of a network infrastructure.
   Currently, the Application Enabled Collaborative Network (AECON)
   activity can provide these necessary solutions.

   Moreover, there are no IETF solutions that can directly be used to
  (1)enable the streaming transfer of bulk-variable/data of SFP based
   network configuration and network topology models between network
   management application systems and network management and controlling
   systems, (2) map the SFP based network configuration and network
   topology models into specific device level configuration models.


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   The APONF activity can provide a solution to this challenge. A
   possible signaling protocol framework that can be enhanced and used
   is the flexible IETF signaling protocol NSIS, see [RFC4080],
   [RFC5971], [RFC5973].

   The main goal of APONF is to:
     o) enable the streaming transfer of bulk-variable/data of the up to
        date SFP based network configuration and network topology models
        between network management application systems and the network
        management and controlling systems, by using and extending the
        IETF Next Steps in Signaling Protocol (NSIS).
     o) map the SFP based network configuration and network topology
        models into specific network management policies, i.e.,
        device level configuration models.


   This document is organized as follows. Section 2 presents the
   terminology. Section 3 provides a brief overview of the use cases
   associated with APONF. The requirements/objectives are provided in
   Section 4. Section 5 presents the relationships between APONF and
   other IETF Working Groups and other IETF activities. The existing
   IETF protocols and methods that can be used by the APONF solutions
   are given in Section 6. Section 7 provides the security
   considerations. The IANA considerations are given in Section 8.
   Section 9 gives the acknowledgements and Section 10 lists the used
   references.

2.  Terminology

   AECON (Application Enabled Collaborative Network): The main goal of
   the AECON activity (currently BOF) is to allow applications to
   explicitly signal their flow characteristics to the network.

   Device level configuration model: supports the description of the
   network management policies and it describes the configuration
   details at the device level.

   Network Management Application: Operational Support System (OSS) like
   applications that help a communication service provider to monitor,
   control, analyze and manage a communication network.

   Network configuration model: provides a declarative configuration of
   the network

   Network topology model: describes the topology of a multi-layer
   network.

   Service Function Chain (SFC):  A service Function chain defines an
   ordered set of service functions that must be applied to packets
   and/or layer-2 frames selected as a result of classification.  The
   implied order may not be a linear progression as nodes may copy to
   more than one branch.  The term service chain is often used as
   shorthand for service function chain.

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   Service Function Path (SFP):  The instantiation of a service function
   chain in the network. Packets follow a service function path from
   a classifier through the required instances of service functions
   in the network.

   VNF (Virtualized Network Function): An implementation of an
   executable software program that constitutes the whole or a part of
   an NF and can be deployed on a virtualization infrastructure.


3.  Use Cases

   This section briefly describes the use cases that are associated with
   different types of network management applications. The detailed
   description of these use cases is provided in other Internet
   draft(s).

3.1 Distributed Data Center

   A large-scale IDC (Inter Data Center) operator provides server
   hosting, bandwidth, and value-added services to enterprises and ISPs,
   and has more than 10 data centers and more than 1Tbs bandwidth in a
   capital city. In current IDC network, traffic is
   routed via configuring policy routes and adjusting routes
   prioritization to choose an outgoing link. This type of static
   provisioning comes with high costs and poor operability. Furthermore,
   the link bandwidth resources in the data centers are not efficiently
   utilized.
   Services usually do not have consistent bandwidth requirements at
   all times of a day, e.g. video ISP usually require more
   bandwidth at non-working hours but require less bandwidth at working
   hours.  Some customers have relative high QoS requirement for their
   services, e.g. IM (Instant Messaging).  Static bandwidth and QoS
   provisioning for all the customers and services is not reasonable and
   not a cost-effective solution.
   APONF can be used to optimize the traffic paths dynamically and
   have the ability to load balance between data centers and links, and
   direct customer traffic via network management policies (e.g.,
   models, software programs routines) based on customer grade and QoS
   requirements.


3.2 IPv6 transition

   The IPv6 transition has been an ongoing process throughout the world
   due to the exhaustion of the IPv4 address space.  However, this
   transition leads to costly end-to-end network upgrades and poses new
   challenges of managing a large number of devices with a variety of
   transitioning protocols.  While IPv6 transition tools exist, there
   are still new challenges to be solved.  Operators may need various
   types of IPv6 transition technologies depending on performance
   requirements, deployment scenarios, etc.



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   To address these difficulties, APONF can be used as the software
   defined unifying approach that can provide a unified way to deploy
   IPv6 in a cost-effective, flexible manner.

3.3. Virtualized Enterprise Applications

   Virtualized Enterprise applications make the Virtualized Network
   Function (VNF) functionality available to enterprise users as a
   service, comparable to the cloud computing concept denoted as the
   Software as a Service (SaaS), see [NIST SP 800-146].
   Virtualized Enterprise application policies include dynamic
   orchestration of virtualized network functions, dynamic
   increase/decrease of network bandwidth, pay as you go billing and
   charging.
   GiLAN is another important application of network function
   virtualization. In mobile core networks, it is preferable that QoS
   provisioning and network function requirements are different for
   subscribers with different profiles. In such scenarios, specialized
   network management applications such as BSS/OSS can send application
   based demands to a policy decision point, which further map these
   application based demands to GiLAN specific VNF policies, and realize
   the required QoS and with appropriate network functions, for example,
   for dynamic path reconfiguration.

   APONF can be used to support the dynamic network reconfiguration
   demands imposed by such virtualized enterprise applications.

3.4.  Source Address Validation and Traceback (SAVI)

   It has been long known that the IPv4/IPv6 transition makes the
   Tracking and validation of source IP address thorny.  Whenever an
   IPvX packet is translated into an IPvY packet, there are three
   Troublesome issues: 1. how to track the origin of the IPvY packet
   which is actually in the IPvX world? 2. how to validate the IPvX
   packet at the edge of the IPvY world to prevent possible spoofing? 3.
   how to protect the IPvY address from being spoofed in the IPvY world?
   SAVI[RFC7039] has given the source address validation solutions for
   both IPv4 and IPv6.
   In order to address the above issues, APONF can be used to block or
   permit the traffic based on the validation of the source address.

  3.5 Using the abstract view of network by service developers

   This use case description argues that service developers can profit
   by using the abstract view of the network during the programming and
   development process instead of manipulating individual devices.
   In this way one can write software that programs an arbitrary
   network.
   APONF can be used to interface the programmed arbitrary network
   into network management policies, i.e., device configuration
   models.



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   4. Requirements/Objectives

   The requirements/objectives that need to be supported by the APONF
   methods, models and protocol solutions are the following ones:

      o) monitor and verify the freshness of the SFP based network
         configuration and network topology models

      o) extend the IETF NSIS protocol to securely and efficiently
         distribute the SFP based network configuration and network
         topology models between network management applications systems
         (e.g., OSS) and the network management and/or controlling
         systems.

      o) use application based demands generated by network management
         applications systems to map the SFP based network configuration
         and network topology models into specific network management
         policies, i.e., into device level configuration models. Such
         application based demands are:

           a) encapsulating, de-encapsulating packets associated with a
            flow into a tunnel (for example, VPN service, IPv6
            transition service demands on the network)

           b) 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).

            c) configure and dynamically reconfigure data centers to the
            steer and reroute traffic associated with a specific flow

            d) configure and dynamically reconfigure data centers to
            change priorities of different types of traffic associated
            with a specific flow

            e) logging the traffic associated with a flow for network
            security service, optimization of the traffic based on the
            IETF ALTO [ALTO]

            f) other actions defined by the administrator

      o) specify the Authentication Authorization and Accounting (AAA)
         method


5. Relationships between APONF and other IETF Working Groups

   The following relationships between APONF and other IETF WGs have
   been identified:





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   IETF SFC WG: the main goal is to document a new approach to service
   delivery and operation, where one of its goals is to realize an
   abstract view of a network by using a service graph denoted as the
   Service Function Path (SFP). This will enable the development of
   suitable models for network configuration and network topology.
   APONF can make use of such network configuration and network topology
   models specified by the IETF SFC.

   AECON (Application Enabled Collaborative Network): The main goal of
   the AECON activity (currently BOF) is to allow applications to
   explicitly signal their flow characteristics to the network. AECON
   can be used to provide the necessary configuration interfaces to
   service developers to program the abstract view of a network
   infrastructure. The AECON activity can be used to provide the
   necessary configuration interfaces to service developers to program
   the SFP based abstract view of a network infrastructure.

   APONF is different than existing WGs and other IETF activities, due
   to the fact that APONF is the only activity that:
     o) enables the streaming transfer of bulk-variable/data of the up
        to date SFP based network configuration and network topology
        models between network management application systems and the
        network management and controlling systems, by using and
        extending the IETF Next Steps in Signaling Protocol (NSIS).
     o) map the SFP based network configuration and network topology
        models into specific network management policies, i.e.,
        device level configuration models.

6.  Existing Protocols and Methods

   The APONF protocol and mechanisms will have an impact on layers 4 and
   above.
   The IETF signaling protocol NSIS, see [RFC4080], [RFC5971], [RFC5973]
   is the signaling protocol framework that can be enhanced and used
   for the streaming transfer of bulk-variable/data of SFP based network
   configuration and network topology models between network management
   application systems and network management and controlling systems.

   Currently NSIS is an on path protocol (supports only signaling for
   entities that are part of the data plane), but APONF needs to use an
   off path protocol (i.e., support signaling for entities that are not
   located on the data plane). Therefore, NSIS needs to be extended in
   two ways:

     1) Extend NSIS GIST [RFC5971] in such a way that it can be used
     for off-path support
     2) Specify a new signaling protocol (NSIS Signaling Layer
        Protocol), similar to the NAT/Firewall NSLP [RFC5973] that
        can be applied and support the APONF use cases.

   The following activities are out of the APONF scope:

   o) the generation of the abstract view of the network infrastructure
   using an SFP based network configuration and network topology models,

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   o) the necessary configuration interfaces to service
      developers to program the abstract view of a network
      infrastructure.

   o) definition of the used SFP based network configuration and
      network topology models

  o) the specification of the network management policies and their
     associated device configuration models


7.  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.

8.  IANA Considerations

   This document has no actions for IANA.

9.  Acknowledgements

   The authors of this draft would like to thank the following
   persons for the provided valuable feedback: 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.


10.  References

10.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
   Requirement Levels", BCP 14, RFC 2119, March 1997.

10.2.  Informative References

   [ALTO] R. Alimi, R. Penno, Y. Yang, "ALTO Protocol", IETF Internet
    draft (work in progress), March 2014

   [DevOps] DevOps website, http://devops.com/

   [NIST SP 800-146] Badger et al.: "Draft Cloud Computing Synopsis and
   recommendations", NIST specifications, May 2011.

   [RFC4080] R. Hancock, G. Karagiannis, J. Loughney,  S. Van den Bosch,
   "Next Steps in Signaling (NSIS): Framework", IETF RFC 4080, June 2005




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   [RFC5971] H. Schulzrinne, R. Hancock, "GIST: General Internet
   Signalling Transport", IETF RFC 5971, October 2010

   [RFC5973] M. Stiemerling, H. Tschofenig, C. Aoun, E. Davies,
   "NAT/Firewall NSIS Signaling Layer Protocol (NSLP)", IETF RFC 5973,
   October 2010

   [RFC7039] J. Wu, J. Bi, M. Bagnulo, F. Baker, C. Vogt, "Source
   Address  Validation Improvement (SAVI) Framework", IETF RFC 7039,
   October 2013.

   [SFC] IETF SFC (Service Function Chaining) WG charter,
   http://datatracker.ietf.org/wg/sfc/charter/

Authors' Addresses

   Georgios Karagiannis
   University of Twente

   Email: g.karagiannis@utwente.nl

   Will(Shucheng) Liu
   Huawei Technologies
   Bantian, Longgang District
   Shenzhen  518129
   P.R. China

   Email: liushucheng@huawei.com

   Tina Tsou
   Huawei Technologies
   Bantian, Longgang District
   Shenzhen  518129
   P.R. China

   Email: Tina.Tsou.Zouting@huawei.com


   Qiong Sun
   China Telecom
   No.118 Xizhimennei street, Xicheng District
   Beijing  100035
   P.R. China

   Email: sunqiong@ctbri.com.cn

   Diego Lopez
   Telefonica

   Email: diego@tid.es




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