Internet DRAFT - draft-karagiannis-aponf-problem-statement

draft-karagiannis-aponf-problem-statement



Network Working Group                                     G. Karagiannis
Internet-Draft                                      University of Twente
Intended status: Informational                                    W. Liu
Expires: January 21, 2015                                        T. Tsou
                                                     Huawei Technologies
                                                                  Q. Sun
                                                           China Telecom
                                                                D. Lopez
                                                              Telefonica
                                                           July 21, 2014


   Problem Statement for Application Policy on Network Functions (APONF)
                  draft-karagiannis-aponf-problem-statement-03

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
   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.



Karagiannis, et al.            Expires January 21, 2015       [Page 1] 

Internet-Draft          APONF Problem Statement                July 2014

   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 . . . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
   4.  Requirements/Objectives . . . . . . . . . . . . . . . . . . . . 8
   5   Relationships between APONF and other IETF Working Groups and 
       IETF activities. . . . . . . . . . . . . . . . . . . . . . . . .9
   6.  Existing Protocols and Methods . . . . . . . . . . . . . . . . 10
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  11
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12




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. 

Karagiannis, et al.            Expires January 21, 2015       [Page 2] 

Internet-Draft          APONF Problem Statement                July 2014

   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 application 
   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 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.

   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 service attributes. Examples 
   of network management applications that can modify the network 
   service attributes are for example, Distributed Data Center 
   Application and IPv6 transitions. 

   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.

   Currently, there are no IETF standard mechanisms or modeling
   languages that can directly be applied to model the network service 
   graphs. IETF has however, created the IETF SFC WG [SFC] to document 
   a new approach to service deliver and operation, where one of its 
   goals is to realize the service function chain that defines an
   ordered set of service functions that must be applied to packets and/
   or layer-2 frames selected as a result of classification. 
   Furthermore, the ACTN (Abstraction and Control of Transport Networks) 
   activity can partially provide a solution to this challenge, by 
   providing means to model the network abstraction.
   Moreover, NFVcon (Network Functions Virtualization configuration) is 
   planning to work on the definition of network service graphs.



Karagiannis, et al.            Expires January 21, 2015       [Page 3] 

Internet-Draft          APONF Problem Statement                July 2014

                         ---------------
                         |  End user   |
                         | application |
                         ---------------
                                |                              
               NFVcon: definition of network service graph 
               ACTN: provides means to model network abstraction 
               AECON:(partially) AECON-developed interface
               SFC WG:(partially) SFC WG -developed model
                                |                              
                                |                              
                       ------------------------
                       | Network management   |
                       |   application system |
                       ------------------------
                                |
                                |     APONF
                                |   transport
                                | (communicates up to date 
                                | attributes of network
                                | service graphs)
                                | 
                                |  
                       ------------------------
                      | Network management &   |
                      | control systems        |
                      | (APONF is mapping      |
                      |  attributes of         |
                      | network service graphs |
                      | into specific network  |
                      | management policies,   |
                      | i.e., device level     |
                      | configuration models)  |
                       -------------------------
                                     |
                 +-------------------+------------------+
                 |                                      |
                 |                                      |
                 |                                      |
   +-------------v---------------+         +------------v-------------+
   |                             |         |                          |
   |                             |   ...   |                          |
   | Network Element             |         | Network Element          |
   +-----------------------------+         +--------------------------+                   
            Figure 1: APONF goal and scope

   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. 
   The AECON (Application Enabled Collaborative Network) activity can 
   partially provide a solution to this challenge, by providing the 
   required flow descriptions. Moreover, the NFVcon activity is planning 
   to work on the definition of this configuration interface. 


Karagiannis, et al.            Expires January 21, 2015       [Page 4] 

Internet-Draft          APONF Problem Statement                July 2014

   Moreover, there are no IETF solutions that can directly be used to 
   (1)enable the streaming transfer of bulk-variable/data of network 
   service graphs between network management application systems and 
   network management and controlling systems, (2) map the attributes of 
   the network service graphs into specific device level configuration 
   models.
   The APONF activity can provide a solution to this challenge. In 
   particular, APONF will investigate and select one of the 
   protocols that have been specified by the IETF. 
   For example, a possible protocol that can be enhanced and used is the 
   Network Configuration Protocol (NETCONF) [RFC6241].   

   The main goal of APONF, see Figure 1, is to:
     o) enable the streaming transfer of bulk-variable/data of the up to 
        date network service graphs between network management 
        application systems and network management and 
        controlling systems, by using and extending an existing 
        IETF signaling protocol.
     o) map the attributes of the network service graph 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

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

   Network service dependencies: dependencies between different service 
   functions/nodes.

   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 management application systems: Systems or platforms  that 
   run the network management application.

   Network configuration model: provides a declarative configuration of 
   the network 

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

Karagiannis, et al.            Expires January 21, 2015         [Page 5] 

Internet-Draft          APONF Problem Statement                July 2014

   Network service: a Network management application. 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.  

   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 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. These attributes can be 
   extended based on the requirements imposed by the network management 
   application. For each network service instance, i.e., network 
   management application instance, an unique network service graph 
   needs to be generated and maintained.

   Network element: a physical entity or a virtual entity that can be 
   locally managed and operated.

   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.

   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 by 
   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.  

Karagiannis, et al.            Expires January 21, 2015         [Page 6] 

Internet-Draft          APONF Problem Statement                July 2014

   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.  A detailed description of this use case is provided in 
   [ID.draft-cheng-aponf-ddc-use-cases].

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.

   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. A detailed description of 
   this use case is provided in [ID.draft-sun-aponf-openv6-use-cases].

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.
   A detailed description of this use case is provided in 
   [ID.draft-huang-aponf-use-cases].

Karagiannis, et al.            Expires January 21, 2015         [Page 7] 

Internet-Draft          APONF Problem Statement                July 2014

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.
   A detailed description of this use case is provided in 
   [ID.draft-bi-aponf-sdsavi].

  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.  A detailed description of this use case is provided in 
   [ID.draft-liu-aponf-using-abstract-view-use-case].


   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 network service graph. 

      o) extend an existing IETF protocol to securely and efficiently 
         distribute the network service graphs 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 network service graph instance 
         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).

Karagiannis, et al.            Expires January 21, 2015         [Page 8] 

Internet-Draft          APONF Problem Statement                July 2014

            c) configure and dynamically reconfigure data centers to 
            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, 

            f) optimization of the traffic based on the IETF ALTO [ALTO] 

            g) other actions defined by the administrator

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


5. Relationships between APONF and other IETF Working Groups and 
   IETF activities

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

   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 use as much as possible these models in order to derive the   
   network service graphs associated with each network service.

   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. 

   The AECON activity can partially provide a solution for the 
   specification of the necessary configuration interfaces to service 
   developers to program the abstract view of a network infrastructure,  
   by providing the required flow descriptions.

   ACTN (Abstraction and Control of Transport Networks): The main goal 
   of this activity is to enable discussion of the architecture, use-
   cases, and requirements that provide abstraction and virtual control 
   of transport networks to various applications. The aim of ACTN is to 
   facilitate virtual network operation: the creation of a virtualized 
   environment allowing operators to view and control multiple multi-
   subnet, multi-technology networks as a single virtualized network.

   ACTN activity can partially provide a solution to the definition of 
   the network service graph, by providing means to model the network 
   abstraction. Moreover, APONF can use all means that will be provided 
   by ACTN on virtual network operation.

Karagiannis, et al.            Expires January 21, 2015         [Page 9] 

Internet-Draft          APONF Problem Statement                July 2014

   NFVcon (Network Functions Virtualization configuration): The main 
   goal of this activity is to support the dynamic configuration of NFV 
   instances.
   The NFVcon activity is planning to focus on the definition of the 
   network service graphs. Moreover, NFVcon might also focus on the 
   specification of the necessary configuration interfaces to service 
   developers to program the abstract view of a network infrastructure. 

   APONF can use the network service graph definitions and the 
   specification of the configuration interfaces provided by the 
   Netcon activity. 

   Use Cases for Autonomic Networking (UCAN): The main goal of UCAN (BOF 
   status) is to collect and analyze use cases for Autonomic Networking. 
   The main objective of Autonomic Networking (AN) is the support of 
   self-management, including self-configuration, self-optimization, 
   self-healing and self-protection. 
   The goal is to find commonalities between various use cases, to be 
   able to determine generic requirements for Autonomic Networking 
   functions and to conclude whether there is scope for a common, 
   generic Autonomic Networking Infrastructure for all autonomic 
   functions.

   APONF can be seen as a possible UCAN use case that can use the 
   Autonomic Networking capabilities provided by UCAN.

   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 network service graphs between network management 
        application systems and the network management and controlling 
        systems 
     o) map the attributes of the network service graph instances 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. Note however, that APONF will also have an impact on layer 3, 
   related to issues such as IP tunneling. 
   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].   
  
   The following activities are out of the APONF scope:

   o) the generation of the abstract view of the network infrastructure  
      using an network service graph

Karagiannis, et al.           Expires January 21, 2015         [Page 10] 

Internet-Draft          APONF Problem Statement                July 2014

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

   o) definition of the used network service graphs 

   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, Jean Francois Tremblay, Tom Taylor.


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/

   [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


Karagiannis, et al.            Expires January 21, 2015         [Page11] 

Internet-Draft          APONF Problem Statement                July 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

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

   [RFC6241] R. Enns, M. Bjorklund, J. Schoenwaelder, A. Bierman,
   "Network Configuration Protocol (NETCONF)", RFC 6241, June 2011.

   [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




Karagiannis, et al.            Expires January 21, 2015        [Page 12] 

Internet-Draft          APONF Problem Statement                July 2014


   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










































Karagiannis, et al.            Expires January 21, 2015        [Page 13]