Network Working Group S. Hyun
Internet-Draft Chosun University
Intended status: Standards Track J. Jeong
Expires: April 23, 2019 T. Roh
S. Wi
Sungkyunkwan University
J. Park
October 20, 2018

I2NSF Registration Interface Data Model


This document defines an information model and a YANG data model for Interface to Network Security Functions (I2NSF) Registration Interface between Security Controller and Developer's Management System (DMS). The objective of these information and data models is to support NSF search, instantiation and registration according to required security capabilities via I2NSF Registration Interface.

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Table of Contents

1. Introduction

A number of virtual network security function instances typically exist in Interface to Network Security Functions (I2NSF) framework [RFC8329]. Since these NSF instances may have different security capabilities, it is important to register the security capabilities of each NSF instance into the security controller after they have been created. In addition, it is required to search or instantiate NSFs of some required security capabilities on demand. As an example, if additional security capabilities are required to meet the new security requirements that an I2NSF user requests, the security controller should be able to request the DMS for NSFs that have the required security capabilities.

This document describes an information model (see Section 5) and a YANG [RFC6020] data model (see Section 6) for the I2NSF Registration Interface [RFC8329] between the security controller and the developer's management system (DMS) to support NSF search, instantiation and registration according to required security capabilities. It also describes the procedure which should be performed by the security controller and the DMS via the Registration Interface using the defined model.

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 [RFC2119].

3. Terminology

This document uses the following terms defined in [i2nsf-terminology], [capability-im], [RFC8329], [nsf-triggered-steering], [supa-policy-data-model], and [supa-policy-info-model]

4. Objectives

5. Information Model

The I2NSF registration interface was only used for registering new NSF instances to Security Controller. In this document, however, we extend its utilization to support on demand NSF instantiation/de-instantiation and describe the information that should be exchanged via the registration interface for the functionality. Moreover, we also define the information model of NSF Profile because, for registration interface, NSF Profile (i.e., capabilities of an NSF) needs to be clarified so that the components of I2NSF framework can exchange the set of capabilities in a standardized manner. This is typically done through the following process:

Security Controller first recognizes the set of capabilities (i.e., NSF Profile) or the signature of a specific NSF required or wasted in the current system.
Developer's Management System (DMS) matches the recognized information to an NSF based on the information model definition.
Developer's Management System creates or eliminates NSFs matching with the above information.
Security Controller can then add/remove the corresponding NSF instance to/from its list of available NSF instances in the system.

| Registration Interface Information Model                          |
|                                                                   |
|       +-+-+-+-+-+-+-+-+-+-+-+-+-+       +-+-+-+-+-+-+-+-+-+-+-+   |
|       |    Instance Management  |       |    Registration     |   |
|       |         Sub-Model       |       |      Sub-Model      |   |
|       +-+-+-+-+-+-+-+-+-+-+-+-+-+       +-+-+-+-+-+-+-+-+-+-+-+   |

Figure 1: Registration Interface Information Model

As illustrated in Figure 1, the information model for Registration Interface consists of two sub-models: instance management, registration sub-models. The instance management functionality and the registration functionality use NSF Profile to achieve their goals. In this context, NSF Profile is the capability objects that describe and/or prescribe inspection capability an NSF instance can provide.

5.1. NSF Instance Managment Mechanism

For the instance management of NSFs, Security Controller in I2NSF framework requires two types of requests: Instantiation Request and Deinstantiation Request. Security Controller sends the request messages to DMS when required. Once receiving the request, DMS conducts creating/eliminating the corresponding NSF instance and responds Security Controller with the results.

          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    +-+-+-+-+-+-+-+-+-+-+
          |  Instantiation/Re-instantiation |    | De-instantiation  |
          |             Request             |    |      Request      |
          +-+-+-+-+-+-+-+-+-^-+-+-+-+-+-+-+-+    +-+-+-+-+-^-+-+-+-+-+
                            |                              |
                            |                              |
                            |                              |
                            |                              |
                  +-+-+-+-+-+-+-+-+-+              +-+-+-+-+-+-+-+-+
                  |  NSF Capability |              |  NSF Access   |
                  |   Information   |              |  Information  |
                  +-+-+-+-+-+-+-+-+-+              +-+-+-+-+-+-+-+-+

Figure 2: Overview of Instance Management Sub-Model

5.2. NSF Registration Mechanism

In order to register a new NSF instance, DMS should generate a Registration Message to Security Controller. A Registration Message consists of an NSF Profile and an NSF Access Information. The former describes the inspection capability of the new NSF instance and the latter is for enabling network access to the new instance from other components. After this registration process, as explained in [capability-im], the I2NSF capability interface can conduct controlling and monitoring the new registered NSF instance.

                              |      NSF      |
                              |  Registration |
                   |                  |                  |
                   |                  |                  |
          +-+-+-+-+-+-+-+-+-+  +-+-+-+-+-+-+-+  +-+-+-+-+-+-+-+-+-+    
          |  NSF Capability |  | NSF Access  |  | NSF Rold-based  |
          |   Information   |  | Information |  |       ACL       |
          +-+-+-+-+-+-+-+-+-+  +-+-+-+-+-+-+-+  +-+-+-+-+-+-+-+-+-+

Figure 3: Registration Mechanism Sub-Model Overview

5.3. NSF Access Information

NSF Access Information contains the followings that are required to communicate with an NSF: IPv4 address, IPv6 address, port number, and supported transport protocol(s) (e.g., Virtual Extensible LAN (VXLAN) [RFC 7348], Generic Protocol Extension for VXLAN (VXLAN-GPE) [draft-ietf-nvo3-vxlan-gpe], Generic Route Encapsulation (GRE), Ethernet etc.). In this document, NSF Access Information is used to identify a specific NSF instance (i.e. NSF Access Information is the signature(unique identifier) of an NSF instance in the overall system).

5.4. NSF Capability Information (Capabilities of an NSF instance)

NSF Profile basically describes the inspection capabilities of an NSF instance. In Figure 4, we show capability objects of an NSF instance. Following the information model of NSF capabilities defiend in [capability-im], we share the same security capabilities: Network-Security Capabilities, Content-Security Capabilities, and Attack Mitigation Capabilities. Also, NSF Profile additionally contains the performance capabilities and role-Based access control list (ACL) as shown in Figure 4.

                 |  Capability   |    
                 |    Objects    |       
            |                       |              |
            |                       |              |
    +-+-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+-+    |
    |Network-Security |     |Content-Security |    |
    |   Capabilities  |     |   Capabilities  |    |
    +-+-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+-+    |
            |                       |
            |                       |
    +-+-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+-+
    |   Performance   |     |Attack Mitigation|
    |   Capabilities  |     |   Capabilities  |
    +-+-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+-+

Figure 4: NSF Profile Overview

5.4.1. Performance Capabilities

This information represents the processing capability of an NSF. This information can be used to determine whether the NSF is in congestion by comparing this with the workload that the NSF currently undergoes. Moreover, this information can specify an available amount of each type of resources such as processing power which are available on the NSF. (The registration interface can control the usages and limitations of the created instance and make the appropriate request according to the status.) As illustrated in Figure 5, this information consists of two items: Processing and Bandwidth. Processing information describes the NSF's available processing power. Bandwidth describes the information about available network amount in two cases, outbound, inbound. This two information can be used for the NSF's instance request.

                         |   Performance   |
                         |   Capabilities  |
                   |                            |
                   |                            | 
           +-+-+-+-+-+-+-+-+            +-+-+-+-+-+-+-+
           |  Processing   |            |  Bandwidth  |
           +-+-+-+-+-+-+-+-+            +-+-+-+-+-+-+-+

Figure 5: Performance Capability Overview

5.5. Role-based Access Control List

This information specifies access policies of an NSF to determine whether to permit or deny the access of an entity to the NSF based on the role given to the entity. Each NSF is associated with a role-based access control list (ACL) so that it can determine whether to permit or deny the access request from an entity. Figure 6 and Figure 7 show the structure of the role-based ACL, which is composed of role-id, access-type, and permit/deny. The role-id identifies roles of entities (e.g., administrator, developer etc.). The access-type identifies the specific type of access requests such as NSF rule configuration/update and NSF monitoring. Consequently, the role-based ACL in Figure 6 and Figure 7 specifies a set of access-types to be permitted and to be denied by each role-id.

                           |   Role-based  |
                           |      ACL      |
                 |                                   |
           +-+-+-+-+-+-+                       +-+-+-+-+-+-+
           | Role-id 1 |          ...          | Role-id N |
           +-+-+-+-+-+-+                       +-+-+-+-+-+-+

Figure 6: Role-based Access Control List

                           |   Role-id i   |
                   |                                 |
             +-+-+-+-+-+-+                     +-+-+-+-+-+-+
             |   Permit  |                     |   Deny    |
             +-+-+-+-+-+-+                     +-+-+-+-+-+-+
                   |                                 |
         +------------------+              +------------------+
         |                  |              |                  |
   +-+-+-+-+-+-+      +-+-+-+-+-+-+  +-+-+-+-+-+-+      +-+-+-+-+-+-+
   |access-type| ...  |access-type|  |access-type| ...  |access-type|
   |     p1    |      |     pn    |  |     d1    |      |     dn    |
   +-+-+-+-+-+-+      +-+-+-+-+-+-+  +-+-+-+-+-+-+      +-+-+-+-+-+-+

Figure 7: Role-id Subtree

6. Data Model

6.1. High-Level YANG

This section provides an overview of the high level YANG.

6.1.1. Definition of Symbols in Tree Diagrams

A simplified graphical representation of the data model is used in this section. The meaning of the symbols used in the following diagrams [i2rs-rib-data-model] is as follows:

6.1.2. Registration Interface

        module : ietf-i2nsf-regs-interface-model
          +--rw regs-req
          |  uses i2nsf-regs-req
          +--rw instance-mgnt-req
          |  uses i2nsf-instance-mgnt-req


Figure 8: High-Level YANG of I2NSF Registration Interface

Each of these sections mirror sections of Section 5.

6.1.3. Registration Request

This section expands the i2nsf-regs-req in Figure 8.

        Registration Request
          +--rw i2nsf-regs-req
            +--rw nsf-capability-information
            |  uses i2nsf-nsf-capability-information
            +--rw nsf-access-info
            |  uses i2nsf-nsf-access-info


Figure 9: High-Level YANG of I2NSF Registration Request

Registration Request contains the capability information of newly created NSF to notify its capability to Security Controller. The request also contains Network Access Information so that the Security Controller can access the NSF.

6.1.4. Instance Management Request

This section expands the i2nsf-instance-mgnt-req in Figure 8.

        Instance Management Request
          +--rw i2nsf-instance-mgnt-req
            +--rw req-level uint16
            +--rw req-id uint64
            +--rw (req-type)?
              +--rw (instanciation-request)
                +--rw in-nsf-capability-information
                |  uses i2nsf-nsf-capability-information
              +--rw (deinstanciation-request)
                +--rw de-nsf-access-info
                |  uses i2nsf-nsf-access-info
              +--rw (updating-request)
                +--rw update-nsf-capability-information
                |  uses i2nsf-nsf-capability-information


Figure 10: High-Level YANG of I2NSF Instance Mgnt Request

Instance management request consists of two types: instanciation-request, deinstanciation-request, and updating-request. The instanciation-request is used to request generation of a new NSF instance with NSF Capability Information which specifies required NSF capability information. The deinstanciation-request is used to remove an existing NSF with NSF Access Information. The updating nsf request is used to updating a existing NSf information with NSF capabilities.

6.1.5. NSF Capability Information

This section expands the i2nsf-nsf-capability-information in Figure 9 and Figure 10.

        NSF Capability Information
          +--rw i2nsf-nsf-capability-information
            +--rw i2nsf-capability
            |  uses ietf-i2nsf-capability
            +--rw performance-capability
            |  uses i2nsf-nsf-performance-caps

Figure 11: High-Level YANG of I2NSF NSF Capability Information

In Figure 11, ietf-i2nsf-capability refers module ietf-i2nsf-capability in [i2nsf-capability-dm]. We add the performance capability because it is absent in [i2nsf-capability-dm] and [netmod-acl-model]

6.1.6. NSF Access Information

This section expands the i2nsf-nsf-access-info in Figure 9 and Figure 10.

        NSF Access Information
          +--rw i2nsf-nsf-access-info
            +--rw nsf-address  inet:ipv4-address
            +--rw nsf-port-address inet:port-number

Figure 12: High-Level YANG of I2NSF NSF Access Informantion

This information is used by other components to access an NSF.

6.1.7. NSF Performance Capability

This section expands the i2nsf-nsf-performance-caps in Figure 11.

        NSF Performance Capability
          +--rw i2nsf-nsf-performance-caps
           +--rw processing
           |   +--rw processing-average uint16
           |   +--rw processing-peak uint16   
           +--rw bandwidth
           |   +--rw outbound 
           |   |  +--rw outbound-average uint16
           |   |  +--rw outbound-peak uint16
           |   +--rw inbound
           |   |  +--rw inbound-average uint16
           |   |  +--rw inbound-peak uint16


Figure 13: High-Level YANG of I2NSF NSF Performance Capability

When the Security Controller requests the Developer Management System to create a new NSF instance, the performance capability is used to specify the performance requirements of the new instance.

6.1.8. Role-Based ACL(Access Control List)

This section expands the ietf-netmod-acl-model in [netmod-acl-model].

        Role-Based ACL
          +--rw role-based-acl
               uses ietf-netmod-acl-model

Figure 14: Role-Based ACL

In [netmod-acl-model], ietf-netmod-acl-model refers module ietf-netmod-acl-model in [netmod-acl-model]. We add the role-based ACL because it is absent in [i2nsf-capability-dm].

6.2. YANG Modules

This section introduces a YANG module for the information model of the required data for the registration interface between Security Controller and Developer's Management System, as defined in Section 5.

            <CODE BEGINS> file "ietf-i2nsf-regs-interface@2018-07-26.yang"
                module ietf-i2nsf-regs-interface {
                  import ietf-inet-types{
                   prefix inet;
                   "IETF I2NSF (Interface to Network Security Functions) 
                    Working Group";

                   "WG Web: <>
                   WG List: <>

                   WG Chair: Adrian Farrel

                   WG Chair: Linda Dunbar

                   Editor: Sangwon Hyun 

                   Editor: Jaehoon Paul Jeong

                   Editor: Taekyun Roh

                   Editor: Sarang Wi

                   Editor: Jung-Soo Park

                    "It defines a YANG data module for Registration Interface.";
                  revision "2018-07-26"{
                    description "The second revision";
                list interface-container{
                    key "interface-name";
                    leaf interface-name{
                      type string;
                      "interface name";
                    container i2nsf-regs-req {
                     "The capability information of newly
                     created NSF to notify its 
                     capability to Security Controller";
                     container nsf-capability-information {
                      uses i2nsf-nsf-capability-information;
                    container nsf-access-info {
                     uses i2nsf-nsf-access-info;
                    container ietf-netmod-acl-model{
                     uses ietf-netmod-acl-model;
                    container i2nsf-instance-mgnt-req {
                     "Required information for instanciation-request, 
                     deinstanciation-request and updating-request";
                     leaf req-level {
                      type uint16;
                     leaf req-id {
                      type uint64;
                      mandatory true;
                     choice req-type {
                      case instanciation-request {
                      container in-nsf-capability-information {
                        uses i2nsf-nsf-capability-information;
                      case deinstanciation-request {
                       container de-nsf-access-info {
                         uses i2nsf-nsf-access-info;
                      case updating-request {
                        "updating nsf's information";
                        container update-nsf-capability-information {
                         uses i2nsf-nsf-capability-information;
                grouping i2nsf-nsf-performance-caps {
                    "NSF performance capailities";
                    container processing{
                      "processing info";
                      leaf processing-average{
                       type uint16;
                      leaf processing-peak{
                       type uint16;
                       "processing peak";
                    container bandwidth{
                      "bandwidth info";
                      container inbound{
                       leaf inbound-average{
                        type uint16;
                       leaf inbound-peak{
                        type uint16;
                      container outbound{
                       leaf outbound-average{
                        type uint16;
                       leaf outbound-peak{
                        type uint16;
                grouping i2nsf-nsf-capability-information {
                  "Detail information of an NSF";
                  container performance-capability {
                   uses i2nsf-nsf-performance-caps;
                  container i2nsf-capability {
                   "It refers draft-ietf-i2nsf-capability-data-model-01.txt 
                grouping ietf-netmod-acl-model {
                  "Detail information";
                  container role-based-acl {
                   "It refers draft-ietf-netmod-acl-model-19.txt
                grouping i2nsf-nsf-access-info {
                  "NSF access information";
                  leaf nsf-address {
                   type inet:ipv4-address;
                   mandatory true;
                  leaf nsf-port-address {
                   type inet:port-number;

            <CODE ENDS>

Figure 15: Data Model of I2NSF Registration Interface

6.2.1. XML Example of Registration Interface Data Model

Requirement: Registering the IDS NSF with VoIP/VoLTE security capability using Registration interface.

Here is the configuration xml for this Registration Interface:

            <?xml version="1.0" encoding="UTF-8"?>
            <rpc xmlns="urn:ietf:params:netconf:base:1.0" message-id="1">
                           <ids-fcn nc:operation="create">
                           <voip-volte-fcn nc:operation="create">

Figure 16: Registration Interface example

7. Security Considerations

This document introduces no additional security threats and SHOULD follow the security requirements as stated in [RFC8329].

8. Acknowledgments

This work was supported by Institute for Information & communications Technology Promotion(IITP) grant funded by the Korea government(MSIP) (No.R-20160222-002755, Cloud based Security Intelligence Technology Development for the Customized Security Service Provisioning).

9. References

9.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs toIndicate Requirement Levels", RFC 2119, March 1997.
[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, October 2010.

9.2. Informative References

[capability-im] Xia, L., Strassner, J., Basile, C. and D. Lopez, "Information Model of NSFs Capabilities", Internet-Draft draft-i2nsf-capability-02, July 2018.
[draft-ietf-nvo3-vxlan-gpe] Maino, Ed., F., Kreeger, Ed., L. and U. Elzur, Ed., "Generic Protocol Extension for VXLAN", Internet-Draft draft-ietf-nvo3-vxlan-gpe-06, April 2018.
[i2nsf-capability-dm] Hares, S., Jeong, J., Kim, J., Moskowitz, R. and Q. Lin, "I2NSF Capability YANG Data Model", Internet-Draft draft-ietf-i2nsf-capability-data-model-01, July 2018.
[i2nsf-terminology] Hares, S., Strassner, J., Lopez, D., Xia, L. and H. Birkholz, "Interface to Network Security Functions (I2NSF) Terminology", Internet-Draft draft-ietf-i2nsf-terminology-06, July 2018.
[i2rs-rib-data-model] Wang, L., Chen, M., Dass, A., Ananthakrishnan, H., Kini, S. and N. Bahadur, "A YANG Data Model for Routing Information Base (RIB)", Internet-Draft draft-ietf-i2rs-rib-data-model-15, May 2018.
[netmod-acl-model] Jethanandani, M., Huang, L., Agarwal, S. and D. Blair, "Network Access Control List (ACL) YANG Data Model", Internet-Draft draft-ietf-netmod-acl-model-19, April 2018.
[nsf-triggered-steering] Hyun, S., Jeong, J., Park, J. and S. Hares, "Service Function Chaining-Enabled I2NSF Architecture", Internet-Draft draft-hyun-i2nsf-nsf-triggered-steering-06, July 2018.
[RFC8329] Lopez, D., Lopez, E., Dunbar, L., Strassner, J. and R. Kumar, "Framework for Interface to Network Security Functions", RFC 8329, February 2018.
[supa-policy-data-model] Halpern, J., Strassner, J. and S. van der Meer, "Generic Policy Data Model for Simplified Use of Policy Abstractions (SUPA)", Internet-Draft draft-ietf-supa-generic-policy-data-model-04, June 2017.
[supa-policy-info-model] Strassner, J., Halpern, J. and S. van der Meer, "Generic Policy Information Model for Simplified Use of Policy Abstractions (SUPA)", Internet-Draft draft-ietf-supa-generic-policy-info-model-03, May 2017.

Authors' Addresses

Sangwon Hyun Department of Computer Engineering Chosun University 309, Pilmun-daero, Dong-gu Gwangju, Jeollanam-do 61452 Republic of Korea EMail:
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: URI:
Taekyun Roh Electrical Computer Engineering Sungkyunkwan University 2066 Seobu-Ro, Jangan-Gu Suwon, Gyeonggi-Do 16419 Republic of Korea Phone: +82 31 290 7222 Fax: +82 31 299 6673 EMail: URI:
Sarang Wi Electrical Computer Engineering Sungkyunkwan University 2066 Seobu-Ro, Jangan-Gu Suwon, Gyeonggi-Do 16419 Republic of Korea Phone: +82 31 290 7222 Fax: +82 31 299 6673 EMail: URI:
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: