Network Working Group                                           J. Jeong
Internet-Draft                                                    H. Kim
Intended status: Standards Track                 Sungkyunkwan University
Expires: January 6, 2017                                         J. Park
                                                                    ETRI
                                                                  T. Ahn
                                                                  S. Lee
                                                           Korea Telecom
                                                            July 5, 2016


 Software-Defined Networking Based Security Services using Interface to
                       Network Security Functions
               draft-jeong-i2nsf-sdn-security-services-05

Abstract

   This document describes a framework, objectives, requirements, and
   use cases for security services based on Software-Defined Networking
   (SDN) using a common Interface to Network Security Functions (I2NSF).
   It first proposes the framework of SDN-based security services in the
   I2NSF framework.  It then explains three use cases, such as a
   centralized firewall system, centralized DDoS-attack mitigation
   system, and centralized VoIP/VoLTE security system.

Status of This Memo

   This Internet-Draft is submitted to IETF in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   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."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
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   This Internet-Draft will expire on January 6, 2017.




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Copyright Notice

   Copyright (c) 2016 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.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Requirements Language  . . . . . . . . . . . . . . . . . . . .  4
   3.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  4
   4.  Overview . . . . . . . . . . . . . . . . . . . . . . . . . . .  5
   5.  Objectives . . . . . . . . . . . . . . . . . . . . . . . . . .  7
   6.  Requirements . . . . . . . . . . . . . . . . . . . . . . . . .  8
   7.  Use Cases  . . . . . . . . . . . . . . . . . . . . . . . . . .  9
     7.1.  Centralized Firewall System  . . . . . . . . . . . . . . .  9
     7.2.  Centralized DDoS-attack Mitigation System  . . . . . . . . 10
     7.3.  Centralized VoIP/VoLTE Security System . . . . . . . . . . 12
   8.  Security Considerations  . . . . . . . . . . . . . . . . . . . 14
   9.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
   10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
     10.1. Normative References . . . . . . . . . . . . . . . . . . . 14
     10.2. Informative References . . . . . . . . . . . . . . . . . . 15
   Appendix A.  Changes from
                draft-jeong-i2nsf-sdn-security-services-04  . . . . . 16

















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1.  Introduction

   Software-Defined Networking (SDN) is a set of techniques that enables
   users to directly program, orchestrate, control and manage network
   resources through software (e.g., SDN applications).  It relocates
   the control of network resources to a dedicated network element,
   namely SDN controller.  The SDN controller uses interfaces to
   arbitrate the control of network resources in a logically centralized
   manner.  It also manages and configures the distributed network
   resources, and provides the abstracted view of the network resources
   to the SDN applications.  The SDN applications can customize and
   automate the operations (including management) of the abstracted
   network resources in a programmable manner via the interfaces
   [RFC7149][ITU-T.Y.3300][ONF-OpenFlow][ONF-SDN-Architecture].

   Due to the increase of sophisticated network attacks, the legacy
   security services become difficult to cope with such network attacks
   in an autonomous manner.  SDN has been introduced to make networks
   more controllable and manageable, and this SDN technology will be
   promising to autonomously deal with such network attacks in a prompt
   manner.

   This document describes a framework, objectives and requirements to
   support the protection of network resources through SDN-based
   security services using a common interface to Network Security
   Functions (NSF) [i2nsf-framework].  It uses an interface to NSF
   (I2NSF) for such SDN-based security services that are performed in
   virtual machines through network functions virtualization [ETSI-NFV].

   This document addresses the challenges of the exisiting systems for
   security services.  As feasible solutions to handle these challenges,
   this document proposes three use cases of the security services, such
   as a centralized firewall system, centralized DDoS-attack mitigation
   system, and centralized VoIP/VoLTE security system.

   For the centralized firewall system, this document raises limitations
   in the legacy firewalls in terms of flexibility and administration
   costs.  Since in many cases, access control management for firewall
   is manually performed, it is difficult to add the access control
   policy rules corresponding to new network attacks in a prompt and
   autonomous manner.  Thus, this situation requires expensive
   administration costs.  This document introduces a use case of SDN-
   based firewall system to overcome these limitations.

   For the centralized DDoS-attack mitigation system, this document
   raises limitations in the legacy DDoS-attack mitigation techniques in
   terms of flexibility and administration costs.  Since in many cases,
   network configuration for the mitigation is manually performed, it is



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   difficult to dynamically configure network devices to limit and
   control suspicious network traffic for DDoS attacks.  This document
   introduces a use case of SDN-based DDoS-attack mitigation system to
   provide an autonomous and prompt configuration for suspicious network
   traffic.

   For the centralized VoIP/VoLTE security system, this documents raises
   challenges in the legacy VoIP/VoLTE security system in terms of
   provisioning time, the granularity of security, cost, and the
   establishment of policy.  This document shows a use case of SDN-based
   VoIP/VoLTE security system to resolve these challenges along in the
   I2NSF framework.

2.  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].

3.  Terminology

   This document uses the terminology described in [RFC7149],
   [ITU-T.Y.3300], [ONF-OpenFlow], [ONF-SDN-Architecture],
   [ITU-T.X.1252], and [ITU-T.X.800].  In addition, the following terms
   are defined below:

   o  Software-Defined Networking: A set of techniques that enables to
      directly program, orchestrate, control, and manage network
      resources, which facilitates the design, delivery and operation of
      network services in a dynamic and scalable manner [ITU-T.Y.3300].

   o  Access Control: A procedure used to determine if an entity should
      be granted access to resources, facilities, services, or
      information based on pre-established rules and specific rights or
      authority associated with the requesting party [ITU-T.X.1252].

   o  Access Control Policy: The set of rules that define the conditions
      under which access may take place [ITU-T.X.800].

   o  Access Control Policy Rules: Security policy rules concerning the
      provision of the access control service [ITU-T.X.800].

   o  Network Resources: Network devices that can perform packet
      forwarding in a network system.  The network resources include
      network switch, router, gateway, WiFi access points, and similar
      devices.





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   o  Firewall: A firewall that is a device or service at the junction
      of two network segments that inspects every packet that attempts
      to cross the boundary.  It also rejects any packet that does not
      satisfy certain criteria for disallowed port numbers or IP
      addresses.

   o  Centralized Firewall System: A centralized firewall that can
      establish and distribute access control policy rules into network
      resources for efficient firewall management.  These rules can be
      managed dynamically by a centralized server for firewall.  SDN can
      work as a network-based firewall system through a standard
      interface between firewall applications and network resources.

   o  Centralized DDoS-attack Mitigation System: A centralized mitigator
      that can establish and distribute access control policy rules into
      network resources for efficient DDoS-attack mitigation.  These
      rules can be managed dynamically by a centralized server for DDoS-
      attack mitigation.  SDN can work as a network-based mitigation
      system through a standard interface between DDoS-attack mitigation
      applications and network resources.

   o  Centralized VoIP/VoLTE Security System: A centralized security
      system that handles the security issues related to VoIP and VoLTE
      services.  SDN can work as a network-based security system through
      a standard interface between VoIP/VoLTE security applications and
      network resources.

4.  Overview

   This section describes the referenced architecture to support SDN-
   based security services, such as centralized firewall system and
   centralized DDoS-attack mitigation system.  Also, it describes a
   framework for SDN-based security services using I2NSF.

   As shown in Figure 1, network security functions (NSFs) as security
   services (e.g., firewall, DDoS-attack mitigation, VoIP/VoLTE, web
   filter, and deep packet inspection) run on the top of SDN controller
   [ITU-T.Y.3300] [ONF-SDN-Architecture].  When an administrator
   enforces security policies for such security services through an
   application interface, SDN controller generates the corresponding
   access control policy rules to meet such security policies in an
   autonomous and prompt manner.  According to the generated access
   control policy rules, the network resources such as switches take an
   action to mitigate network attacks, for example, dropping packets
   with suspicious patterns.






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   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           Network Security Functions          |
   |    (e.g., firewall, DDoS-attack mitigation,   | Application
   |VoIP/VoLTE, web filter, deep packet inspection)| Layer
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   --------------------------------------------------------------------
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (Application-
   |               Application Support             |  Control Interface)
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Orchestration                | Switch Controller
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Layer
   |                   Abstraction                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   --------------------------------------------------------------------
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (Resource-
   |                 Control Support               |  Control Interface)
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          Data Transport and Processing        | Resource Layer
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     Figure 1: High-level Architecture for SDN-based Security Services

   Figure 2 shows a framework to support SDN-based security services
   using I2NSF [i2nsf-framework].  As shown in Figure 2, I2NSF client
   can use security services by delivering their high-level security
   policies to security controller via client facing interface.
   Security controller asks NSFs to perform function-level security
   services via NSF facing interface.  The NSFs run on top of virtual
   machines through Network Functions Virtualization (NFV) [ETSI-NFV].
   NSFs ask switch controller to perform their required security
   services on switches under the supervision of switch controller.  In
   addition, security controller uses registration interface to
   communicate with developer's management system for registering (or
   deregistering) the developer's NSFs into (or from) the NFV system
   using the I2NSF framework.

   NSF facing interface between security controller and NSFs can be
   implemented by Network Configuration Protocol (NETCONF) [RFC6241]
   with a data modeling language called YANG [RFC6020] that describes
   function-level security services.  A data model in
   [i2nsf-cap-interface-yang] can be used for the I2NSF capability
   interface, which is NSF facing interface.

   The proposed framework of SDN-based security services can be combined
   to a security management architecture in [i2nsf-sec-mgnt-arch] for
   handling high-level security policies as well as low-level security
   policies.




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   Also, the proposed framework can enforce low-level security policies
   in NSFs by using a service function chaining (SFC) enabled I2NSF
   architecture in [i2nsf-sfc-enabled-arch].

5.  Objectives

   o  Prompt reaction to new network attacks: SDN-based security
      services allow private networks to defend themselves against new
      sophisticated network attacks.

   o  Automatic defense from network attacks: SDN-based security
      services identify the category of network attack (e.g., malware
      and DDoS attacks) and take counteraction for the defense without
      the intervention of network administrators.

   o  Network-load-aware resource allocation: SDN-based security
      services measure the overhead of resources for security services
      and dynamically select resources considering load balance for the
      maximum network performance.
































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       +------------+
       |I2NSF Client|
       +------------+
              ^
              | Client Facing Interface
              v
    +-------------------+     Registration     +-----------------------+
    |Security Controller|<-------------------->|Developer's Mgnt System|
    +-------------------+       Interface      +-----------------------+
              ^
              | NSF Facing Interface
              v
    +-------------------+ +-------------------+    +-------------------+
    |       NSF 1       |-|       NSF 2       |....|       NSF n       |
    +-------------------+ +-------------------+    +-------------------+
              ^
              | SDN Northbound Interface
              v
     +-----------------+
     |Switch Controller|
     +-----------------+
              ^
              | SDN Southbound Interface
              v
         +--------+ +--------+      +--------+
         |Switch 1|-|Switch 2|......|Switch m|
         +--------+ +--------+      +--------+

     Figure 2: A Framework for SDN-based Security Services using I2NSF

6.  Requirements

   SDN-based security services provide dynamic and flexible network
   resource management to mitigate network attacks, such as malware and
   DDoS attacks.  In order to support this capability, the requirements
   for SDN-based security services are described as follows:

   o  SDN-based security services are required to support the
      programmability of network resources to mitigate network attacks.

   o  SDN-based security services are required to support the
      orchestration of network resources and SDN applications to
      mitigate network attacks.

   o  SDN-based security services are required to provide an application
      interface allowing the management of access control policies in an
      autonomous and prompt manner.




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   o  SDN-based security services are required to provide a resource-
      control interface for the control of network resources to mitigate
      network attacks.

   o  SDN-based security services are required to provide the logically
      centralized control of network resources to mitigate network
      attacks.

   o  SDN-based security services are required to support the seamless
      services to mitigate network attacks.

   o  SDN-based security services are required to provide the dynamic
      control of network resources to mitigate network attacks.

7.  Use Cases

   This section introduces three use cases for security services based
   on SDN: (i) centralized firewall system, (ii) centralized DDoS-attack
   mitigation system, and (iii) centralized VoIP/VoLTE security system.

7.1.  Centralized Firewall System

   For the centralized firewall system, a centralized network firewall
   can manage each network resource and firewall rules can be managed
   flexibly by a centralized server for firewall (called Firewall).  The
   centralized network firewall controls each switch for the network
   resource management and the firewall rules can be added or deleted
   dynamically.

   The procedure of firewall operations in the centralized firewall
   system is as follows:

   1.  Switch forwards an unknown flow's packet to Switch Controller.

   2.  Switch Controller forwards the unknown flow's packet to an
       appropriate security service application, such as Firewall.

   3.  Firewall analyzes the headers and contents of the packet.

   4.  If Firewall regards the packet as a malware's packet with a
       suspicious pattern, it reports the malware's packet to Switch
       Controller.

   5.  Switch Controller installs new rules (e.g., drop packets with the
       suspicious pattern) into switches.

   6.  The malware's packets are dropped by switches.




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   For the above centralized firewall system, the existing SDN protocols
   can be used through standard interfaces between the firewall
   application and switches [RFC7149][ITU-T.Y.3300][ONF-OpenFlow]
   [ONF-SDN-Architecture].

   Legacy firewalls have some challenges such as the expensive cost,
   performance, management of access control, establishment of policy,
   and packet-based access mechanism.  The proposed framework can
   resolve these challenges through the above centralized firewall
   system based on SDN as follows:

   o  Cost: The cost of adding firewalls to network resources such as
      routers, gateways, and switches is substantial due to the reason
      that we need to add firewall on each network resource.  To solve
      this, each network resource can be managed centrally such that a
      single firewall is manipulated by a centralized server.

   o  Performance: The performance of firewalls is often slower than the
      link speed of network interfaces.  Every network resource for
      firewall needs to check firewall rules according to network
      conditions.  Firewalls can be adaptively deployed among network
      switches, depending on network conditions in the framework.

   o  The management of access control: Since there may be hundreds of
      network resources in an administered network, the dynamic
      management of access control for security services like firewall
      is a challenge.  In the framework, firewall rules can be
      dynamically added for new malware.

   o  The establishment of policy: Policy should be established for each
      network resource.  However, it is difficult to describe what flows
      are permitted or denied for firewall within a specific
      organization network under management.  Thus, a centralized view
      is helpful to determine security policies for such a network.

   o  Packet-based access mechanism: Packet-based access mechanism is
      not enough for firewall in practice since the basic unit of access
      control is usually users or applications.  Therefore, application
      level rules can be defined and added to the firewall system
      through the centralized server.

7.2.  Centralized DDoS-attack Mitigation System

   For the centralized DDoS-attack mitigation system, a centralized
   DDoS-attack mitigation can manage each network resource and
   manipulate rules to each switch through a centralized server for
   DDoS-attack mitigation (called DDoS-attack Mitigator).  The
   centralized DDoS-attack mitigation system defends servers against



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   DDoS attacks outside private network, that is, from public network.

   Servers are categorized into stateless servers (e.g., DNS servers)
   and stateful servers (e.g., web servers).  For DDoS-attack
   mitigation, traffic flows in switches are dynamically configured by
   traffic flow forwarding path management according to the category of
   servers [AVANT-GUARD].  Such a managenent should consider the load
   balance among the switches for the defense against DDoS attacks.

   The procedure of DDoS-attack mitigation operations in the centralized
   DDoS-attack mitigation system is as follows:

   1.  Switch periodically reports an inter-arrival pattern of a flow's
       packets to Switch Controller.

   2.  Switch Controller forwards the flow's inter-arrival pattern to an
       appropriate security service application, such as DDoS-attack
       Mitigator.

   3.  DDoS-attack Mitigator analyzes the reported pattern for the flow.

   4.  If DDoS-attack Mitigator regards the pattern as a DDoS attack, it
       computes a packet dropping probability corresponding to
       suspiciousness level and reports this DDoS-attack flow to Switch
       Controller.

   5.  Switch Controller installs new rules into switches (e.g., forward
       packets with the suspicious inter-arrival pattern with a dropping
       probability).

   6.  The suspicious flow's packets are randomly dropped by switches
       with the dropping probability.

   For the above centralized DDoS-attack mitigation system, the existing
   SDN protocols can be used through standard interfaces between the
   DDoS-attack mitigator application and switches [RFC7149]
   [ITU-T.Y.3300][ONF-OpenFlow][ONF-SDN-Architecture].

   The centralized DDoS-attack mitigation system has challenges similar
   to the centralized firewall system.  The proposed framework can
   resolve these challenges through the above centralized DDoS-attack
   mitigation system based on SDN as follows:

   o  Cost: The cost of adding DDoS-attack mitigators to network
      resources such as routers, gateways, and switches is substantial
      due to the reason that we need to add DDoS-attack mitigator on
      each network resource.  To solve this, each network resource can
      be managed centrally such that a single DDoS-attack mitigator is



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      manipulated by a centralized server.

   o  Performance: The performance of DDoS-attack mitigators is often
      slower than the link speed of network interfaces.  The checking of
      DDoS attacks may reduce the performance of the network interfaces.
      DDoS-attack mitigators can be adaptively deployed among network
      switches, depending on network conditions in the framework.

   o  The management of network resources: Since there may be hundreds
      of network resources in an administered network, the dynamic
      management of network resources for performance (e.g., load
      balancing) is a challenge for DDoS-attack mitigation.  In the
      framework, as dynamic network resource management, traffic flow
      forwarding path management can handle the load balancing of
      network switches [AVANT-GUARD].  With this management, the current
      and near-future workload can be spread among the network switches
      for DDoS-attack mitigation.  In addition, DDoS-attack mitigation
      rules can be dynamically added for new DDoS attacks.

   o  The establishment of policy: Policy should be established for each
      network resource.  However, it is difficult to describe what flows
      are permitted or denied for new DDoS-attacks (e.g., DNS reflection
      attack) within a specific organization network under management.
      Thus, a centralized view is helpful to determine security policies
      for such a network.

7.3.  Centralized VoIP/VoLTE Security System

   For the centralized VoIP/VoLTE security system, a centralized VoIP/
   VoLTE security system can monitor each VoIP/VoLTE flow and manage
   VoIP/VoLTE security rules controlled by a centralized server for
   VoIP/VoLTE security service (called VoIP IPS).  The VoIP/VoLTE
   security system controls each switch for the VoIP/VoLTE call flow
   management by manipulating the rules that can be added, deleted or
   modified dynamically.

   The procedure of VoIP/VoLTE security operations in the centralized
   VoIP/VoLTE security system is as follows:

   1.  A switch forwards an unknown call flow's signal packet (e.g., SIP
       packet) to Switch Controller.  Also, if the packet belongs to a
       matched flow's packet related to SIP (called matched SIP packet),
       Switch forwards the packet to Switch Controller so that the
       packet can be checked by an NSF for VoIP (i.e., VoIP IPS) via
       Switch Controller, which monitors the behavior of its SIP call.

   2.  Switch Controller forwards the unknown flow's packet or the
       matched SIP packet to an appropriate security service function,



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       such as VoIP IPS.

   3.  VoIP IPS analyzes the headers and contents of the signal packet,
       such as IP address, calling number, and session description
       [RFC4566].

   4.  If VoIP IPS regards the packet as a spoofed packet by hackers or
       a scanning packet searching for VoIP/VoLTE devices, it requests
       the Switch Controller to block that packet and the subsequent
       packets that have the same call-id.

   5.  Switch Controller installs new rules (e.g., drop packets) into
       switches.

   6.  The illegal packets are dropped by switches.

   For the above centralized VoIP/VoLTE security system, the existing
   SDN protocols can be used through standard interfaces between the
   VoIP IPS application and switches [RFC7149][ITU-T.Y.3300]
   [ONF-OpenFlow][ONF-SDN-Architecture].

   Legacy hardware based VoIP IPSes have some challenges, such as
   provisioning time, the granularity of security, expensive cost, and
   the establishment of policy.  The proposed framework can resolve
   these challenges through the above centralized VoIP/VoLTE security
   system based on SDN as follows:

   o  Provisioning: The provisioning time of setting up a legacy VoIP
      IPS to network is substantial because it takes from some hours to
      some days.  By managing the network resources centrally, VoIP IPS
      can provide more agility in provisioning both virtual and physical
      network resources from a central location.

   o  The granularity of security: The security rules of a legacy VoIP
      IPS are compounded considering the granularity of security.  The
      proposed framework can provide more granular security by
      centralizing security control into a switch controller.  The VoIP
      IPS can effectively manage security rules throughout the network.

   o  Cost: The cost of adding VoIP IPS to network resources, such as
      routers, gateways, and switches is substantial due to the reason
      that we need to add VoIP IPS on each network resource.  To solve
      this, each network resource can be managed centrally such that a
      single VoIP IPS is manipulated by a centralized server.

   o  The establishment of policy: Policy should be established for each
      network resource.  However, it is difficult to describe what flows
      are permitted or denied for VoIP IPS within a specific



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      organization network under management.  Thus, a centralized view
      is helpful to determine security policies for such a network.

   So far this document has described the procedure and impact of the
   three use cases for security services.  To support these use cases in
   the proposed framework, a data model described in
   [i2nsf-cap-interface-yang] can be used as NSF facing interface along
   with NETCONF [RFC6241].

8.  Security Considerations

   The proposed SDN-based framework in this document is derived from the
   I2NSF framework [i2nsf-framework], so the security considerations of
   the I2NSF framework should be included in this document.  Therefore,
   proper secure communication channels should be used the delivery of
   control or management messages among the components in the proposed
   framework.

   This document shares all the security issues of SDN that are
   specified in the "Security Considerations" section of [ITU-T.Y.3300].

9.  Acknowledgements

   This document was supported by Institute for Information &
   communications Technology Promotion (IITP) grant funded by the Korea
   government (MSIP) [10041244, Smart TV 2.0 Software Platform] and by
   MSIP/IITP [R0166-15-1041, Standard Development of Network Security
   based SDN].

   This document has greatly benefited from inputs by Jinyong Kim,
   Daeyoung Hyun, Mahdi Daghmehchi-Firoozjaei, and Geumhwan Cho.

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.

   [i2nsf-framework]           Lopez, E., Lopez, D., Dunbar, L.,
                               Strassner, J., Zhuang, X., Parrott, J.,
                               Krishnan, R., and S. Durbha, "Framework
                               for Interface to Network Security
                               Functions",
                               draft-ietf-i2nsf-framework-01,
                               June 2016.




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

   [RFC6020]                   Bjorklund, M., "YANG - A Data Modeling
                               Language for the Network Configuration
                               Protocol (NETCONF)", RFC 6020,
                               October 2010.

10.2.  Informative References

   [i2nsf-cap-interface-yang]  Jeong, J., Kim, J., Hyun, D., Park, J.,
                               and T. Ahn, "YANG Data Model of Interface
                               to Network Security Functions Capability
                               Interface", draft-jeong-i2nsf-capability-
                               interface-yang-00, July 2016.

   [i2nsf-sec-mgnt-arch]       Kim, H., Ko, H., Oh, S., Jeong, J., and
                               S. Lee, "An Architecture for Security
                               Management in I2NSF Framework", draft-
                               kim-i2nsf-security-management-
                               architecture-01, July 2016.

   [i2nsf-sfc-enabled-arch]    Hyun, S., Woo, S., Yeo, Y., Jeong, J.,
                               and J. Park, "Service Function Chaining-
                               Enabled I2NSF Architecture",
                               draft-hyun-i2nsf-sfc-enabled-i2nsf-00,
                               July 2016.

   [RFC7149]                   Boucadair, M. and C. Jacquenet,
                               "Software-Defined Networking: A
                               Perspective from within a Service
                               Provider Environment", RFC 7149,
                               March 2014.

   [ITU-T.Y.3300]              Recommendation ITU-T Y.3300, "Framework
                               of Software-Defined Networking",
                               June 2014.

   [ONF-OpenFlow]              ONF, "OpenFlow Switch Specification
                               (Version 1.4.0)", October 2013.

   [ONF-SDN-Architecture]      ONF, "SDN Architecture", June 2014.

   [ITU-T.X.1252]              Recommendation ITU-T X.1252, "Baseline
                               Identity Management Terms and
                               Definitions", April 2010.



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   [ITU-T.X.800]               Recommendation ITU-T X.800, "Security
                               Architecture for Open Systems
                               Interconnection for  CCITT Applications",
                               March 1991.

   [AVANT-GUARD]               Shin, S., Yegneswaran, V., Porras, P.,
                               and G. Gu, "AVANT-GUARD: Scalable and
                               Vigilant Switch Flow Management in
                               Software-Defined Networks", ACM CCS,
                               November 2013.

   [ETSI-NFV]                  ETSI GS NFV 002 V1.1.1, "Network
                               Functions Virtualisation (NFV);
                               Architectural Framework", October 2013.

   [RFC4566]                   Handley, M., Jacobson, V., and C.
                               Perkins, "SDP: Session Description
                               Protocol", RFC 4566, July 2006.

Appendix A.  Changes from draft-jeong-i2nsf-sdn-security-services-04

   The following changes were made from
   draft-jeong-i2nsf-sdn-security-services-04:

   o  According to the change of terminology in the I2NSF framework, the
      names of the components and interfaces are updated as follows:
      Application Controller -> I2NSF Client, Security Function (SF) ->
      Network Security Function (NSF), Vendor System -> Developer's
      Management System, Service Layer Interface -> Client Facing
      Interface, Capability Layer Interface -> NSF Facing Interface.

   o  Three use cases described in this document can use a data model
      corresponding to the information model for the I2NSF capability
      interface.

   o  The proposed framework of SDN-based security services can be
      combined to a security management architecture for handling
      security policies.

   o  The proposed framework can enforce low-level security policies in
      NSFs by using a service function chaining (SFC) enabled I2NSF
      architecture.









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Authors' Addresses

   Jaehoon Paul Jeong
   Department of Software
   Sungkyunkwan University
   2066 Seobu-Ro, Jangan-Gu
   Suwon, Gyeonggi-Do  16419
   Republic of Korea

   Phone: +82 31 299 4957
   Fax:   +82 31 290 7996
   EMail: pauljeong@skku.edu
   URI:   http://iotlab.skku.edu/people-jaehoon-jeong.php


   Hyoungshick Kim
   Department of Software
   Sungkyunkwan University
   2066 Seobu-Ro, Jangan-Gu
   Suwon, Gyeonggi-Do  16419
   Republic of Korea

   Phone: +82 31 299 4324
   Fax:   +82 31 290 7996
   EMail: hyoung@skku.edu
   URI:   http://seclab.skku.edu/people/hyoungshick-kim/


   Jung-Soo Park
   Electronics and Telecommunications Research Institute
   218 Gajeong-Ro, Yuseong-Gu
   Daejeon  305-700
   Republic of Korea

   Phone: +82 42 860 6514
   EMail: pjs@etri.re.kr


   Tae-Jin Ahn
   Korea Telecom
   70 Yuseong-Ro, Yuseong-Gu
   Daejeon  305-811
   Republic of Korea

   Phone: +82 42 870 8409
   EMail: taejin.ahn@kt.com





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   Se-Hui Lee
   Korea Telecom
   70 Yuseong-Ro, Yuseong-Gu
   Daejeon  305-811
   Republic of Korea

   Phone: +82 42 870 8162
   EMail: sehuilee@kt.com











































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