I2NSF BOF S. Hares
Internet-Draft Huawei
Intended status: Standards Track A. Pastor
Expires: April 20, 2016 Telefonica I+D
K. Wang
China Mobile
D. Zhang
M. Zarny
Goldman Sachs
October 18, 2015

Analysis of Use Cases and Gaps in Technology for I2NSF


This document provides a summary of the I2NSF use cases plus a summary of the stat of the art in industries and IETF work which is relevant to the Interface to Network Security Function (I2NSF). The I2NSF focus is to define data models and interfaces in order to control and monitor the physical and virtual aspects of network security functions. The use cases are organized in two basic scenarios. In the access network scenario, mobile and residential users access NSF capabilities using their network service provider infrastructure. In the data center scenario customers manage NSFs hosted in the data center infrastructure.

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Table of Contents

1. Introduction

Enterprise, residential, and mobile customers are becoming more and more aware of the need for network security, just to find that security services are hard to operate and become expensive in the case of reasonably sophisticated ones. This general trend has caused numerous operators and security vendors to start to leverage on cloud-based models to deliver security solutions. In particular, the methods around Network Function Virtualization (NFV) are meant to facilitate the elastic deployment of software images providing the network services, and require the management of various resources by customers, who may not own or physically host those network functions.

There are numerous benefits by defining such interfaces. Operators could provide more flexible and customized security services for specific users and this would provide more efficient and secure protection to each user.

This document provides an analysis of the use cases, gaps analysis of existing technology, recommendations for requirements for I2NSF, and security considerations.

         Customer   +     Access     +     PoP/Datacenter
                    |                |     +--------+
                    |          ,-----+--.  |Network |
                    |        ,'      |   `-|Operator|
    +-------------+ |       /+----+  |     |Mgmt Sys|
    | Residential |-+------/-+vCPE+----+   +--------+
    +-------------+ |     /  +----+  |  \     |    :
                    |    /           |   \    |     |
        +-------+   |   ;    +----+  |    +----+    |
        | Cloud |---+---+----+ vPE+--+----+ NSF|    |
        +-------+   |   :    +----+  |    +----+    |
                    |    :           |   /          |
         +--------+ |    :   +----+  |  /           ;
         | Mobile |-+-----\--+vEPC+----+           /
         +--------+ |      \ +----+  |          ,-'
                    |       `--.     |      _.-'
                    |           `----+----''
                    +                +

                         Figure 1:  NSF and actors

1.1. What is I2NSF

A Network Security Function (NSF) is a function used to ensure integrity, confidentiality, or availability of network communications, to detect unwanted network activity, or to block or at least mitigate the effects of unwanted activity. NSFs are provided and consumed in increasingly diverse environments. Users could consume network security services enforced by NSFs hosted by one or more providers - which may be their own enterprise, service providers, or a combination of both. Similarly, service providers may offer their customers network security services that are enforced by multiple security products, functions from different vendors, or open source technologies. NSFs may be provided by physical and/or virtualized infrastructure. Without standard interfaces to control and monitor the behavior of NSFs, it has become virtually impossible for providers of security services to automate service offerings that utilize different security functions from multiple vendors.

1.2. I2NSF Standarization

The Interface to NSF devices (I2NSF) work proposes to standardize a set of software interfaces and data modules to control and monitor the physical and virtual NSFs. Since different security vendors support different features and functions, the I2NSF will focus on the flow-based NSFs that provide treatment to packets or flows such found in IPS/IDS devices, web filtering devices, flow filtering devices, deep packet inspection devices, pattern matching inspection devices, and re-mediation devices.

There are two layers of interfaces envisioned in the I2NSF approach:

For the I2NSF capability layer, the I2NSF work proposes an interoperable protocol that passes NSF provisioning rules and orchestration information between I2NSF client on a network manager and I2NSF agent on an NSF device. It is envisioned that clients of the I2NSF interfaces include management applications, service orchestration systems, network controllers, or user applications that may solicit network security resources.

The I2NSF work to define this protocol includes the following work:

1.3. Structure of the document

This document reviews the terminology (section 3), analyzes the use cases (section 4) and gaps in current technology (section 5), recommends certain requirements for I2NSF protocol(section 6), and discusses security consideration (section 8).

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].

In this document, these words will appear with that interpretation only when in ALL CAPS. Lower case uses of these words are not to be interpreted as carrying RFC-2119 significance.

3. Terminology

4. Use Cases

This section discusses general use cases, access use cases, and cloud use cases.

4.1. General Use Cases

User request security services through specific clients (a customer app, the NSP BSS/OSS or management platform...) and the appropriate NSP network entity will invoke the (v)NSFs according to the user service request. We will call this network entity the security controller. The interaction between the entities discussed above (client, security controller, NSF) is shown in the following diagram:

   +-------+              |          |                  +-------+
   |       |  Interface 1 |Security  |   Interface 2    | NSF(s)|
   |Client <------------->           <------------------>       |
   |       |              |Controller|                  |       |
   +-------+              |          |                  +-------+

                  Figure 2: Interaction between Entities

Interface 1 is used for receiving security requirements from client and translating them into commands that NSFs can understand and execute. Moreover, it is also responsible for giving feedback of the NSF security statistics to client. Interface 2 is used for interacting with NSFs according to commands, and collect status information about NSFs.

4.1.1. Instantiation and Configuration of NSFs

Client sends collected security requirements through Interface 1 to the security controller in the NSP network, which then translates them into a a set of security functions. Then the corresponding NSFs are instantiated and configured through Interface 2.

As an example, consider an enterprise user A who wants to prevent a certain kind of traffic from flowing to their network. Such a requirement is sent from client to security controller through Interface 1. The security controller translates the requirement into a firewall function plus a rules for filtering out TCP and/or UDP data packets. Then it instantiates a firewall NSF through Interface 2. The corresponding filter rules are also configured onto this firewall NSF through Interface 2.

4.1.2. Updating of NSFs

A user can direct the client to require the update of security service functions, including adding/deleting a security service function and updating configurations of former security service function.

As an example, consider a user who has instantiated a security service before and decides to enable an additional IDS service. This requirement will be sent to the security controller through Interface 1 and be translated, so the security controller instantiates and configures an IDS NSF through Interface 2.

4.1.3. Collecting the Status of NSFs

When users want to get the executing status of security service, they can request the status statistics information of NSFs from the client. The security controller will collect NSF status statistics information through Interface 2, consolidate them, and give feedback to client through Interface 1. This interface can be used to collect not only individual service information, but also aggregated data suitable for tasks like infrastructure security assessment.

4.1.4. Validation of NSFs

Customers may require to validate NSF availability, provenance, and its correct execution. This validation process, especially relevant for vNSFs, includes at least

In order to achieve this the security controller has to collect security measurements and share them with an independent and trusted third party, allowing the user to attest the NSF by using Interface 1 and the information of the trusted third party.

4.2. Access Networks

This scenario describes use cases for users (enterprise user, network administrator, residential user...) that request and manage security services hosted in the network service provider (NSP) infrastructure. Given that NSP customers are essentially users of their access networks, the scenario is essentially associated with their characteristics, as well as with the use of vNSFs.

The Virtual CPE described in [NFVUC] use cases #5 and #7 cover the model of virtualization for mobile and residential access, where the operator may offload security services from the customer local environment (or even the terminal) to the operator infrastructure supporting the access network.

These use cases defines the operator interaction with vNSFs through automated interfaces, typically by B2B communications performed by the operator management systems (OSS/BSS).

4.2.1. vNSF Deployment

The deployment process consists of instantiating a NSF on a Virtualization Infrastructure (NFVI), within the NSP administrative domain(s) or with other external domain(s). This is a required step before a customer can subscribe to a security service supported in the vNSF.

4.2.2. vNSF Customer Provisioning

Once a vNSF is deployed, any customer can subscribe to it. The provisioning lifecycle includes:

4.3. Cloud Datacenter Scenario

In a datacenter, network security mechanisms such as firewalls may need to be added or removed dynamically for a number of reasons. It may be explicitly requested by the user, or triggered by a pre- agreed-upon service level agreement (SLA) between the user and the provider of the service. For example, the service provider may be required to add more firewall capacity within a set timeframe whenever the bandwidth utilization hits a certain threshold for a specified period. This capacity expansion could result in adding new instances of firewalls. Likewise, a service provider may need to provision a new firewall instance in a completely new environment due to a new requirement.

The on-demand, dynamic nature of deployment essentially requires that the network security "devices" be in software or virtual form factors, rather than in a physical appliance form. (This is a provider-side concern. Users of the firewall service are agnostic, as they should, as to whether or not the firewall service is run on a VM or any other form factor. Indeed, they may not even be aware that their traffic traverses firewalls.)

Furthermore, new firewall instances need to be placed in the "right zone" (domain). The issue applies not only to multi-tenant environments where getting the tenant right is of paramount importance but also to environments owned and operated by a single organization with its own service segregation policies. For example, an enterprise may mandate that firewalls serving Internet traffic and business-to-business (B2B) traffic be separate; or that IPS/IDS services for investment banking and non-banking traffic be separate for regulatory reasons.

4.3.1. On-Demand Virtual Firewall Deployment

A service provider operated cloud data center could serve tens of thousands of clients. Clients' compute servers are typically hosted on virtual machines (VMs), which could be deployed across different server racks located in different parts of the data center. It is often not technically and/or financially feasible to deploy dedicated physical firewalls to suit each client's myriad security policy requirements. What is needed is the ability to dynamically deploy virtual firewalls for each client's set of servers based on established security policies and underlying network topologies.

        |                             |
       +---+                         +-+-+
       |vFW|                         |vFW|
       +---+                         +-+-+
         |    Client #1                |  Client #2
      ---+-------+---               ---+-------+---
       +-+-+   +-+-+                 +-+-+   +-+-+
       |vM |   |vM |                 |vM |   |vM |
       +---+   +---+                 +---+   +---+

              Figure 3:  NSF in DataCenter

4.3.2. Firewall Policy Deployment Automation

Firewall configuration today is a highly complex process that involves consulting established security policies, translating those policies into firewall rules, further translating those rules into vendor-specific configuration sets, identifying all the firewalls, and pushing configurations to those firewalls.

This is often a time consuming, complex and error-prone process even within a single organization/enterprise framework. It becomes far more complex in provider-owned cloud networks that serve myriad customers.

Automation can help address many of these issues. Automation works best when it can leverage a common set of standards that will work across multiple entities. Client-Specific Security Policy in Cloud VPNs

Clients of service provider operated cloud data centers need not only secure virtual private networks (VPNs) but also virtual security functions that enforce the clients' security policies. The security policies may govern communications within the clients' own virtual networks and those with external networks. For example, VPN service providers may need to provide firewall and other security services to their VPN clients. Today, it is generally not possible for clients to dynamically view, much less change, what, where and how security policies are implemented on their provider-operated clouds. Indeed, no standards-based framework that allows clients to retrieve/manage security policies in a consistent manner across different providers exists.

4.4. Considerations on Policy and Configuration

NSF configurations can vary from simple rules (i.e. block a DDoS attack) to very complex configuration ( i.e. define a user firewall rules per application, protocol, source and destination port and address). The possibility of using configuration templates per control and management type is a common option as well.

A NSP can push security policies using complex configurations in their managed vNSF through its management system. The open Control and management interface has to accommodate this application-driven behavior.

Computer-savvy customers may pursue a similar application-driven configuration through the open Control and management interface, but standard residential and mobile customers may prefer to use the definition of security policies in the form of close-to-natural- language sentences with high-level directives or a guide configuration process. The representation for these policies will be of the form:

   +-------+   +------+   +------+   +------------------+
   |Subject| + |Action| + |Object| + |Field_type = Value|
   +-------+   +------+   +------+   +------------------+

        Figure 4: High-Level Security Policy Format

Subject indicates the customer or device in the access.

Action can include a variety of intent-based actions: check, redirect, allow, block, record, inspect..

Object can be optional and specifies the nature of the action. The default is all the customer traffic, but others possible values are connections and connections attempts.

Field_type allows to create fine-grained policies, including destinations list (i.e. IPs, domains), content types (i.e. files, emails), windows of time (i.e. weekend), protocol or network service (i.e. HTTP).

An example of a customer policy is:

4.4.1. Translating Policies into NSF Capabilities

Policies expressed in the above model are suitable for what we depicted as Interface 1 in Figure 2. In order to allow the security controller to deal with the different NSFs an intermediate representation used for expressing specific configurations in a device-independent format is required. For this purpose, the definition of a set of security capabilities provides a means for categorizing the actions performed by network security functions. An initial, high-level set of such capabilities consists of:

Service Chain will allow for more than one of the aforementioned functions to engage in a specific order to a particular flow

5. Gap Analysis

5.1. Structure of the gap analysis

This document provides a analysis of the gaps in the state of art in the following industry forums:

5.2. IETF Gap analysis

The IETF gap analysis first examines the IETF mechanisms which have been developed to secure the IP traffic flows through a network. Traffic filters have been defined by IETF specifications at the access points, the middle-boxes, or the routing systems. Protocols have been defined to carry provisioning and filtering traffic between a management system and an IP system (router or host system). Current security work (SACM working group (WG), MILE WG, and DOTS WG) is providing correlation of events monitored with the policy set by filters. This section provides a review the filter work, protocols, and security correlation for monitors.

5.2.1. Traffic Filters Overview

The earliest filters defined by IETF were access filters which controlled the acceptance of IP packet data flows. Additional policy filters were created as part of the following protocols:

Today NETMOD and I2RS Working groups are specifying additional filters in Yang modules to be used as part of the NETCONF or I2RS enhancement of NETCONF/RESTCONF.

The routing filtering is outside the scope of the flow filtering, but flow filtering may be impacted by route filtering. An initial model for the routing policy is in [I-D.shaikh-rtgwg-policy-model]

This section provides an overview of the flow filtering as an introduction to the I2NSF GAP analysis. Additional detail on NETCONF, NETMOD, I2RS, PCP, and NSIS is available in the Detailed I2NSF analysis. Data Flow Filters in NETMOD and I2RS

The current work on expanding these filters is focused oncombining a configuration and monitoring protocol with Yang data models. [I-D.ietf-netmod-acl-model] provides a set of access lists filters which can permit or deny traffic flow based on headers at the MAC, IP layer, and Transport layer. The configuration and monitoring protocols which can pass the filters are: NETCONF protocol [RFC6241], RESTCONF [I-D.ietf-netconf-restconf], and the I2RS protocol. The NETCONF and RESTCONF protocols install these filters into forwarding tables. The I2RS protocol uses the ACLs as part of the filters installed in an ephemeral protocol-independent filter-based RIB [I-D.kini-i2rs-fb-rib-info-model] which controls the flow of traffic on interfaces specifically controlled by the I2RS filter-based FIB.

   +---------------+    /  \     +---------------+
   | Device: ACLs  |-- /     \---|Device: ACLS   |
   | I2RS FB RIB   |             | I2RS FB RIB   |
   |routing policy |             | routing policy|
   |               |             |               |
   +---------------+  data flow  +---------------+
        Figure 5 -I2RS Filter-Based RIB 

The I2RS protocol is a programmatic interface to the routing system. At this time, the I2RS is targeted to be extensions to the NETCONF/RESTCONF protocols to allow the NETCONF/RESTCONF protocol to support a highly programmatic interface with high bandwidth of data, highly reliable notifications, and ephemeral state (see [I-D.ietf-i2rs-architecture]). Please see the background section on I2RS for additional details on the requirements for this extension to the NETCONF/RESTCONF protocol suite.

The vocabulary set in [I-D.ietf-netmod-acl-model] is limited, so additional protocol independent filters were written for the I2RS Filter-Based RIBs in [I-D.hares-i2rs-bnp-eca-data-model], and protocol specific filters for SFC [I-D.dunbar-i2rs-discover-traffic-rules].

One thing important to note is that NETCONF and RESTCONF manage device layer yang models. However, as figure 6 shows, there are multiple device level, network-wide level, and application level yang modules. The access lists defined by the device level forwarding table may be impacted by the routing protocols, the I2RS ephemeral protocol independent Filter-Based FIB, or some network-wide security issue (IPS/IDS).

|Application Network Wide: Intent            |
|Network-wide level: L3SM L3VPN service model|
|Device level: Protocol Independent: I2RS    |
| RIB, Topology, Filter-Based RIB            |
|Device Level:Protocol Yang modules          |
| (ISIS, OSPF, BGP, EVPN, L2VPN, L3VPN, etc.)    
| Device level: IP and System: NETMOD Models | 
| (config and oper-state), tunnels,          | 
|  forwarding filters                        |
 Figure 6 levels of Yang modules I2NSF Gap analysis

The gap is that none of the current work on these filters considers all the variations of data necessary to do IPS/IDS, web-filters, stateful flow-based filtering, security-based deep packet inspection, or pattern matching with re-mediation. The I2RS Filter-Based RIB work is the closest associated work, but the focus has not been on IDS/IPS, web-filters, security-based deep packet inspection, or pattern matching with re-mediation.

The I2RS Working group (I2RS WG) is focused on the routing system so security expertise for these IDP/IPS, Web-filter, security-based deep-packet inspection has not been targeted for this WG.

Another gap is there is no capability registry (an IANA registry) that identifies the characteristics and behaviours of NSFs in vendor-neutral vocabulary without requiring the NSFs to be standardized.

What I2NSF can use from NETCONF/RESTCONF and I2RS

I2NSF should consider using NETCONF/RESTCONF protocol and the I2RS proposed enhancement to the NETCONF/RESTCONF protocol. Middle-box Filters Midcom

Midcom Summary: MIDCOM developed the protocols for applications to communicate with middle boxes. However, MIDCOM have not used by the industry for a long time. This is because there was a lot of IPR encumbered technology and IPR was likely a bigger problem for IETF than it is today. MIDCOM is not specific to SIP. It was very much oriented to NAT/FW devices. SIP was just one application that needed the functionality. MIDCOM is reservation-oriented and there was an expectation that the primary deployment environment would be VoIP and real-time conferencing, including SIP, H.323, and other reservation-oriented protocols. There was an assumption that there would be some authoritative service that would have a view into endpoint sessions and be able to authorize (or not) resource allocation requests. In other word, there's a trust model there that may not be applicable to endpoint-driven requests without some sort of trusted authorization mechanisms/tools. Therefore, there is a specific information model applied to security devices, and security device requests, that was developed in the context of an SNMP MIB. There is also a two-stage reservation model, which was specified in order to allow better resource management.

Why I2NSF is different than Midcom

MIDCOM is different than I2NSF because its SNMP scheme doesn't work with the virtual network security functions (vNSF) management.

MidCom RFCs: Security Work Overview

Today's NSFs in security devices can handle flow-based security by providing treatment to packets/flows, such as IPS/IDS, Web filtering, flow filtering, deep packet inspection, or pattern matching and re-mediation. These flow-based security devices are managed and provisioned by network management systems.

No standardized set of interoperable interfaces control and manage the NSFs so that a central management system can be used across security devices from multiple Vendors. I2NSF work plan is to standardize a set of interfaces by which control and management of NSFs may be invoked, operated, and monitored by:

The flow-filtering configuration and management must fit into the existing security area's work plan. This section considers how the I2NSF fits into the security area work under way in the SACM (security automation and control), DOTS (DDoS Open Threat Signalling), and MILE (Management Incident Lightweight Exchange). Security Work and Filters

In the proposed I2NSF work plan, the I2NSF security network management system controls many NSF nodes via the I2NSF Agent. This control of data flows is similar to the COPS example in section 5.7.4.

             | I2NSF      |       
             | Client     |
             |            |			 
             | security   |
             | NMS system |			 
   +-----+    /  \    +-----+
   |I2NSF|--/     \---|I2NSF|
   |Agent|            |Agent|
   |     |            |     |
   | NSF |            | NSF |
 --| ----|------------|-----|-----
   +-----+  data flow +-----+
     Figure 7 

The other security protocols work to interact within the network to provide additional information in the following way: I2NSF interaction

The network management system that the I2NSF client resides on may interact with other clients or agents developed for the work ongoing in the SACM, DOTS, and MILES working groups. This section describes how the addition of I2NSF's ability to control and monitor NSF devices is compatible and synergistic with these existing efforts.

             +----------+    +------+
 +--------+  | security |====| DOTS |    
 |SACNM   |  | NMS      |    |client|---+
 |consumer|  |..........|\  +------+    |
 +--------+==|SACM  *1  | \             |
        +----|repository|  \            |
	    |	 |..........|   +-------+   |
        |    | I2NSF    |   |MILES  |   |
 +------|-+  | client   |   |client |   |
 |SACM    |  +----------+   +-----:-+   |
 |Info.   |     / \               :     |
 |provider|    /   \              :     |
 +--------+   /     \             :     |
   +-----+   /       \    +-----+ :     |
   |I2NSF|--/         \---|I2NSF| :     |
   |     |                |     | :     |
   |     |                |MILES|.:     |
   |     |                |Agent|       |
   |     |                |DOTS |       |
   |     |                |Agent|-------+
 --| ----|----------------|-----|-----
   +-----+  data flow     +-----+
 *1 - this is the SACM Controller (CR) with
      its broker/proxy/repository show as 
	  described in the SACM architecture.
     Figure 8 

Figure 8 provides a diagram of a system the I2NSF, SACM, DOTS and MILES client-agent or consumer-broker-provider are deployed together. The following are possible positive interactions these scenario might have: Benefits from the Interaction

I2NSF's ability to provide a common interoperable and vendor neutral interface may allow the security NMS to use a single change to change filters. SACM provides an information model to describe end-points, but does not link this directly to filters.

DOTS creates black-lists based on source and destination IP address, transport port number, protocol ID, and traffic rate. Like NETMOD's, ACLS are not sufficient for all filters or control desired by the NSF boxes.

The incident data captured by MILES will not have enough filter information to provide NSF devices with general services. The I2NSF will be able to handle the MILE incident data and create alerts or reports for other security systems.


5.3.1. ETSI Overview

Network Function Virtualization (NFV) provides the service providers with flexibility, cost effective and agility to offer their services to customers. One such service is the network security function which guards the exterior of a service provider or its customers.

The flexibility and agility of NFV encourages service providers to provide different products to address business trends in their market to provide better service offerings to their end user. A traditional product such as the network security function (NSF) may be broken into multiple virtual devices each hosted from another vendor. In the past, network security devices may have been single sourced from a small set of vendors - but in the NFV version of NSF devices, this reduced set of sources will not provide a competitive edge. Due to this market shift, the network security device vendors are realizing that the proprietary provisioning protocols and formats of data may be a liability. Out of the NFV work has arisen a desire for a single interoperable network security device provisioning and control protocol.

The I2NSF will be deployed along networks using other security and NFV technology. As section 3 described, the NFV NSF security is deployed along side other security functions (AAA, SACM, DOTS, and MILE devices) or deep-packet-inspection. The ETSI Network Functions Virtualization: NFV security: Security and Trust guidance document (ETSI NFV SEC 003 1.1.1 (2014-12)) indicates that multiple administrative domains will deployed in carrier networks. One example of these multiple domains is hosting of multiple tenant domains (telecom service providers) on a single infrastructure domain (infrastructure service) as figure 9 shows. The ETSI Inter inter-VNFM document (aka Ve-Vnfn) between the element management system and the Virtual network function is the equivalent of the interface between the I2NSF client on a management system and the I2NSF agent on the network security feature VNF.

 +--:   OSS/BSS         :
 |   ....................
 |  +-------------------------+
 |  |                         |
 |  | ........   ........     | 
 |  | :  EMS1 :   : EMS  :    |  ETSI inter-VNFM 
 |  | ....||...   ...||...    |  (Ve-Vnfn)
 |  |     ||         || ==========I2NSF interface 
 |  | ....||...   ...||...    |
 |  | :  VNF1 :   : VNF1 :    | Tenant domain 
 |  | ....||...   ...||...    |  
 |  | ....||..... ...||...... | infrastructure 
 |  | :virtual  : :virtual  : | domain 
 |  | :computing: :computing: | with virtual 
 |  | ........... ........... | network
 |  | +=====================+ ---------
 |  | | virtualization layer|           | 
 |  | +=====================+           |
 |  | ........... .......... .......... |
 |====:computing: :storage : :network : |
    | :hardware : :hardware: :hardware: | 
	| ........... .......... .......... |
	|  hardware resources               |
    Figure 9 	  

The ETSI proof of concept work has worked on the following security proof of concepts:

5.3.2. I2NSF Gap Analysis

The I2NSF will be deployed on top of virtual computing linked together by virtual routers configured by NETCONF/RESTCONF or I2RS which provision and monitoring the L1, L2, l3 and service pathways through the network.

In the NFV-related productions, the current architecture does not have a protocol to maintain an interoperability provisioning from I2NSF client to I2NSF agent. The result is that service providers have to manage the interoperability using private protocols. In response to this problem, the device manufacturers and the service providers have begun to discuss an I2NSF protocol for interoperable passing of provisioning and filter in formation.

Open source work (such as OPNFV) provides a common code base for providers to start their NFV work from. However, this code base faces the same problem. There is no defacto standard protocol.

5.4. OPNFV

The OPNFV (www.opnfv.org) is a carrier-grade integrated, open source platform focused on accelerating the introduction of new Network Function Virtualization (NFV) products and service. The OPNFV Moon project is focused on adding the security interface for a network management system within the Tenant NFVs and the infrastructure NFVs (as shown in figure 4). This section provides an overview of the OPNFV Moon project and a gap analysis between I2NSF and the OPNFV Moon Project.

5.4.1. OPNFV Moon Project

The OPNFV moon project (https://wiki.opnfv.org) is a security management system. NFV uses cloud computing technologies to virtualize the resources and automate the control. The Moon project is working on a security manager for the Cloud computing infrastructure (https://wiki.opnfv.org/moon). The Moon project proposes to provision a set of different cloud resources/services for VNFs (Virtualized Network Functions) while managing the isolation of VNS, protection of VNFs, and monitoring of VNS. Moon is creating a security management system for OPNFV with security managers to protect different layers of the NFV infrastructure. The Moon project is choosing various security project mechanisms “a la cart” to enforcement related security managers. A security management system integrates mechanisms of different security aspects. This project will first propose a security manager that specifies users’ security requirements. It will also enforce the security managers through various mechanisms like authorization for access control, firewall for networking, isolation for storage, logging for tractability, etc.

The Moon security manager operates a VNF security manager at the ETSI VeVnfm level where the I2NSF protocol is targeted as figure 10 shows. Figure 10 also shows how the OPNFV VNF Security project mixes the I2NSF level with the device level.

The Moon project lists the following gaps in OpenStack:

Moon addresses these issues adding authorization, logging, IDS, enforcement of network policy, and storage protection. Moon is based on OpenStack Keystone.

Deliverable time frame: 2S 2015

 +--:   OSS/BSS         :
 |   ....................
 |  +-------------------------+
 |  |                         |
 |  | ........   ........     | 
 |  | :  EMS1 :   : EMS  :    |  ETSI inter-VNFM 
 |  | ....||...   ...||...    |  (Ve-Vnfn)
 |  |     ||         || ==========I2NSF interface 
 |  | ....||...   ...||...    | Moon VNF === Moon VNF    
 |  | :       :   :      :    | Security     Security MGR
 |  | :  VNF1 :   : VNF1 :    |  
 |  | ....||...   ...||...    | Tenant domain 
 |  | ....||..... ...||...... | infrastructure 
 |  | :virtual  : :virtual  : | domain 
 |  | :computing: :computing: | with virtual 
 |  | ........... ........... | network
 |  | +=====================+ |--------
 |  | | virtualization layer| |        
 |  | +=====================+ 
 |  |                =============Moon VNF ===Moon VI 
|   |                     security project    Security MGR
 |  | ........... .......... .......... |
 |====:computing: :storage : :network : |
    | :hardware : :hardware: :hardware: | 
    | ........... .......... .......... |
    |  hardware resources               |
    Figure 10 	  

5.4.2. Gap Analysis for OPNFV Moon Project

OpenStack congress does not provide vendor independent systems.

5.5. OpenStack Security Firewall

OpenStack has advanced features of: a) API for managing security groups (http://docs.openstack.org/admin-guide-cloud/content/section_securitygroups.html) and b) firewalls as a service (http://docs.openstack.org/admin-guide-cloud/content/fwaas_api_abstractions.html).

This section provides an overview of this open stack work, and a gap analysis of how I2NSF provides additional functions

5.5.1. Overview of API for Security Group

The security group with the security group rules provides ingress and egress traffic filters based on port. The default group drops all ingress traffic and allows all egress traffic. The groups with additional filters are added to change this behaviour. To utilize the security groups, the networking plug-in for Open Stack must implement the security group API. The following plug-ins in OpenSTsack currently implement this security: ML2, Open vSwitch, Linux Bridge, NEC, and VMware NSX. In addition, the correct firewall driver must be added to make this functional.

5.5.2. Overview of Firewalls as a Service

Firewall as a service is an early release of an API that allows early adopters to test network implementations. It contains APIs with parameters for firewall rules, firewall policies, and firewall identifiers. The firewall rules include the following information:

The firewall policies include the following information:

The firewall table provides the following information:

5.5.3. I2NSF Gap analysis

The OpenStack work is preliminary (security groups and firewall as a service). This work does not allow any of the existing network security vendors provide a management interface. Security devices take time to be tested for functionality and their detection of security issues. The OpenStack work provides an interesting simple set of filters, and may in the future provide some virtual filter service. However, at this time this open source work does not address the single management interfaces for a variety of security devices.

I2NSF is proposing rules that will include Event-Condition-matches (ECA) with the following matches

The I2NSF is proposing action for these ECA policies of:

5.6. CSA Secure Cloud

5.6.1. CSA Overview

The Cloud Security Alliance (CSA)(www.cloudsecurityaliance.org) defined security as a service (SaaS) in their Security as a Service working group (SaaS WG) during 2010-2012. The CSA SaaS group defined ten categories of network security (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_V1_0.pdf) and provides implementation guidance for each of these ten categories This section provides an overview of the CSA SaaS working groups documentation and a Gap analysis for I2NSF CSA Security as a Service(SaaS)

The CSA SaaS working group defined the following ten categories, and provided implementation guidance on these categories:

  1. Identity Access Management (IAM) (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_1_IAM_Implementation_Guidance.pdf)
  2. Data Loss Prevention (DLP) (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_2_DLP_Implementation_Guidance.pdf)
  3. Web Security (web) (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_3_Web_Security_Implementation_Guidance.pdf),
  4. Email Security (email) (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_4_Email_Security_Implementation_Guidance.pdf),
  5. Security Assessments (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_5_Security_Assessments_Implementation_Guidance.pdf),
  6. Intrusion Management (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_6_Intrusion_Management_Implementation_Guidance.pdf),
  7. Security information and Event Management (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_7_SIEM_Implementation_Guidance.pdf),
  8. Encryption (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_8_Encryption_Implementation_Guidance.pdf),
  9. Business Continuity and Disaster Recovery (BCDR) https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_9_BCDR_Implementation_Guidance.pdf), and
  10. Network Security (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_10_Network_Security_Implementation_Guidance.pdf).

The sections below give an overview these implementation guidances Identity Access Management (IAM)

document: (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_1_IAM_Implementation_Guidance.pdf)

The identity management systems include the following services:

 +------------+                      +--------+
 | IAM device | ---- SLA ------------| secure |    
 |            |     Access review    | access |
 |            |    security events   |  NMS   |
 |            |    access tracing    |        |
 +---||-------+    Audit report      +---||---+
     ||                                  ||    
     ||         +------------------+     ||       
     ========== |Filter enforcement|=====||
   Figure 11	 

The IAM device communications with the security management system that controls the filtering of data. The CSA SaaS IAM specification states that interoperability between IAM devices and secure access network management systems is a a problem. This 2012 implementation report confirms there is a gap with I2NSF Data Loss Prevention (DLP)

Document: (https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_2_DLP_Implementation_Guidance.pdf)

The data loss prevention (DLP)services must address:

The CSA SaaS DLP device communications require that it have the enforcement capabilities to do the following:

 +------------+                      +--------+
 | DLP device | ---- SLA ------------| secure |    
 |            |    Alert and log     | access |
 |            |    delete data       |  NMS   |
 |            |    filter/reroute    |        |
 +---||-------+    encrypt data      +---||---+
     ||                                  ||    
     ||         +------------------+     ||       
     ========== |Filter enforcement|=====||
   Figure 12 Web security(Web))

Document: https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_3_Web_Security_Implementation_Guidance.pdf

The web security services must address:

The CSA SaaS Web services device communications require that it have the enforcement capabilities to do the following:

 +------------+                      +--------+
 |Web security| ---- SLA ------------| secure |    
 |            |    Alert and log     | access |
 |            |    delete data       |  NMS   |
 |            | filter/reroute data  |        |
 |            | ensure bandwdith/QOS |        |
 |            | monitor encrypted    |        |
 |            |    data              |        | 
 +---||-------+    encrypt data      +---||---+
     ||                                  ||    
     ||         +------------------+     ||       
     ========== |Filter enforcement|=====||
   Figure 13	 

All of these features either require the I2NSF standardized I2NSF client to I2NSF agent to provide multi-vendor interoperability. Email Security (email))

Document: https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_4_Email_Security_Implementation_Guidance.pdf

The CSA Document recommends that email security services must address:

The CSA SaaS Email security services requires that it have the enforcement capabilities to do the following:

 +------------+                      +--------+
 |   Email    | ---- SLA ------------| secure |    
 |  security  | alert/log malware    | access |
 |            | alert/log email spam |  NMS   |
 |            | filter/reroute data  |        |
 |            | ensure bandwidth/QOS |        |
 |            | monitor encrypted    |        |
 |            |    data              |        | 
 +---||-------+    encrypt data      +---||---+
     ||                                  ||    
     ||         +------------------+     ||       
     ========== |Filter enforcement|=====||
   Figure 14

All of these features require the I2NSF standardized I2NSF client to I2NSF agent to provide multi-vendor interoperability. Security Assessment

Document: https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_5_Security_Assessments_Implementation_Guidance.pdf

The CSA SaaS Security assessment indicates that assessments need to be done on the following devices:

All of these features require the I2NSF working group standardize the way to pass these assessments to and from the I2NSF client on the I2NSF management system and the I2NSF Agent. Intrusion Detection

Document: https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_6_Intrusion_Management_Implementation_Guidance.pdf)

The CSA SaaS Intrusion detection management includes intrusion detection through: devices:

Intrusion response includes both:

The CSA SaaS recommends the intrusion security management systems include provisioning and monitoring of all of these types of intrusion detection (IDS) or intrusion protection devices. The management of these systems requires also requires:

 +------------+                      +--------+
 |  IDS/IPS   | ---- Info  ----------| secure |    
 |  security  | alert/log intrusion  | access |
 |            | notify administrator |  NMS   |
 |            | Map alerts to Tenant |        |
 |            |filter/reroute traffic|        |
 |            | remote data storage  |        |     
 +---||-------+                      +---||---+
     ||                                  ||    
     ||         +------------------+     ||       
     ========== |Filter enforcement|=====||
   Figure 15	 

All of these features require the I2NSF standardized I2NSF client to I2NSF agent to provide multi-vendor interoperability. Security Information and Event Management(SEIM)

Document: https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_7_SIEM_Implementation_Guidance.pdf)

The Security Information and Event Management (SEIM) receives data from a wide range of security systems such as Identity management systems (IAM), data loss prevention (DLP), web security (Web), email security (email), intrusion detection/prevision (IDS/IPS)), encryption, disaster recovery, and network security. The SEIM combines this data into a single streams. All the requirements for data to/from these systems are replicated in these systems needs to give a report to the SIEM system.

A SIEM system would be prime candidate to have a I2NSF client that gathers data from an I2NSF Agent associated with these various types of security systems. The CSA SaaS SIEM functionality document suggests that one concern is to have standards that allow timely recording and sharing of data. I2NSF can provide this. Encryption

Document: https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_8_Encryption_Implementation_Guidance.pdf

The CSA SaaS Encryption implementation guidance document considers how one implements and manages the following security systems:

The wide variety of encryption services require the security management systems be able to provision, monitor, and control the systems that are being used to encrypt data. This document indicates in the implementation sections that the standardization of interfaces to/from management systems are key to good key management systems, encryption systems, and crypto-systems. Business Continuity and Disaster Recovery (BC/DR)

Document: https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_9_BCDR_Implementation_Guidance.pdf

The CSA SaaS Business Continuity and Disaster Recovery (BC/DR) implementation guidance document considers the systems that implement the the contingency plans and measures designed and implemented to ensure operational resiliency in the event of any service interruptions. BC/DR systems includes:

These BC/DR systems must handle data backup and recovery, server backup/recovery, and data center (virtual/physical) backup and recovery. Recovery as a service (RaaS) means that the BC/DR services are being handled by management systems outside the enterprise.

The wide variety of BC/DR requires the security management systems to be able to communicate provisioning, monitor, and control those systems that are being used to back-up and restore data. An interoperable protocol that allows provision and control of data center's data, servers, and data center management devices devices is extremely important to this application. Recovery as a Service (SaaS) indicates that these services need to be able to be remotely management.

The CSA SaaS BC/BR documents indicate how important a standardized I2NSF protocol is. Network Security Devices

Document: https://downloads.cloudsecurityalliance.org/initiatives/secaas/SecaaS_Cat_10_Network_Security_Implementation_Guidance.pdf

The CSA SaaS Network Security implementation recommendation includes advice on:

These network security systems require provisioning, monitoring, and the ability for the security management system to subscribe to receive logs, snapshots of capture data, and time synchronization. This document states the following:

The CSA SaaS network security indicates that the I2NSF must be secure so that the I2NSF Client-Agent protocol does not become a valid threat vector. In additions, the need for the management protocol like I2NSF is critical in the sprawl of Cloud environment.

5.6.2. I2NSF Gap Analysis

The CSA Security as a Service (SaaS) document show clearly that there is a gap between the ability of the CSA SaaS devices to have a vendor neutral, inoperable protocol that allow the multiple of network security devices to communicate passing provisioning and informational data. Each of the 10 implementation agreements points to this as a shortage. The I2NSF yang models and protocol is needed according to the CSA SaaS documents.

5.7. In-depth Review of IETF protocols


The IETF NETCONF working group has developed the basics of the NETCONF protocol focusing on secure configuration and querying operational state. The NETCONF protocol [RFC6241] may be run over TLS [RFC6639] or SSH ([RFC6242]. NETCONF can be expanded to defaults [RFC6243], handling events ([RFC5277] and basic notification [RFC6470], and filtering writes/reads based on network access control models (NACM, [RFC6536]). The NETCONF configuration must be committed to a configuration data store (denoted as config=TRUE). Yang models identify nodes within a configuration data store or an operational data store using a XPath expression (document root ---to --- target source). NETCONF uses an RPC model and provides protocol for handling configs (get-config, edit-config, copy-config, delete-config, lock, unlock, get) and sessions (close-session, kill-session). The NETCONF Working Group has developed RESTCONF, which is an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastores defined in NETCONF.

RESTCONF supports “two edit condition detections” – time stamp and entity tag. RESTCONF uses a URI encoded path expressions. RESTCONF provides operations to get remote servers options (OPTIONS), retrieve data headers (HEAD), get data (GET), create resource/invoke operation (POST), patch data (PATCH), delete resource (DELETE), or query.


5.7.2. I2RS Protocol

Based on input from the NETCONF working group, the I2RS working group decided to re-use the NETCONF or RESTCONF protocols and specify additions to these protocols rather than create yet another protocol (YAP).

The required extensions for the I2RS protocol are in the following drafts:

At this time, NETCONF and RESTCONF cannot handle the ephemeral data store proposed by I2RS, the publication and subscription requirements, the traceability, or the security requirements for the transport protocol and message integrity.

5.7.3. NETMOD Yang modules

NETMOD developed initial Yang models for interfaces [RFC7223]), IP address ([RFC7277]), IPv6 Router advertisement ([RFC7277]), IP Systems ([RFC7317]) with system ID, system time management, DNS resolver, Radius client, SSH, syslog ([I-D.ietf-netmod-syslog-model]), ACLS ([I-D.ietf-netmod-acl-model]), and core routing blocks ([I-D.ietf-netmod-routing-cfg] The routing working group (rtgwg) has begun to examine policy for routing and tunnels.

Protocol specific Working groups have developed yang models for ISIS ([I-D.ietf-isis-yang-isis-cfg]), OSPF ([I-D.ietf-ospf-yang]), and BGP ( merge of [I-D.shaikh-idr-bgp-model] and [I-D.zhdankin-idr-bgp-cfg] with the bgp policy proposed multiple Working groups (idr and rtgwg)). BGP Services yang models have been proposed for PPB EVPN ([I-D.tsingh-bess-pbb-evpn-yang-cfg]), EVPN ([I-D.zhuang-bess-evpn-yang]), L3VPN ([I-D.zhuang-bess-l3vpn-yang]), and multicast MPLS/BGP IP VPNs ([I-D.liu-bess-mvpn-yang]).

5.7.4. COPS

One early focus on flow filtering based on policy enforcement of traffic entering a network is the 1990s COPS [RFC2748] design (PEP and PDP) as shown in figure 16. The Policy decision point kept network-wide policy (E.g. ACLs) and sent it to Policy enforcements who then would control what data flows between the two These decision points controlled data flow from PEP to PEP. [RFC3084] describes COPS use for policy provisioning.

   +-----+    /  \    +-----+
   |PEP1 |--/     \---|PEP2 |
   |     | ACL/policy |     |
   | 	 |	          |     |
 --| ----|------------|-----|-----
   +-----+  data flow +-----+
           Figure 16

COPS had a design of Policy Enforcement Points (PEP), and policy Decision Points (PDP) as shown in figure 16. These decision points controlled flow from PEP to PEP.

Why COPS is no longer used

Security in the network in 2015 uses specific devices (IDS/IPS, NAT firewall, etc) with specific policies and profiles for each types of device. No common protocol or policy format exists between the policy manager (PDP) and security enforcement points.

COPs RFCs: [RFC4261], [RFC2940], , [RFC3084], , [RFC3483]

Why I2NSF is different COPS

COPS was a protocol for policy related to Quality of Service (QoS) and signalling protocols (e.g. RSVP) (security, flow, and others). I2NSF creates a common protocol between security policy decision points (SPDP) and security enforcement points (SEP). Today's security devices currently only use proprietary protocols. Manufacturers would like a security specific policy enforcement protocol rather than a generic policy protocol.

5.7.5. PCP

As indicated by the name, the Port Control Protocol (PCP) enables an IPv4 or IPv6 host to flexibly manage the IP address and port mapping information on Network Address Translators (NATs) or firewalls, to facilitate communication with remote hosts.


Why is I2NSF different from PCP:

Here are some aspects that I2NSF is different from PCP:

5.7.6. NSIS - Next steps in Signalling

NSIS is for standardizing an IP signalling protocol (RSVP) along data path for end points to request its unique QoS characteristics, unique FW policies or NAT needs (RFC5973) that are different from the FW/NAT original setting. The requests are communicated directly to the FW/NAT devices. NSIS is like east-west protocols that require all involved devices to fully comply to make it work.

NSIS is path-coupled, it is possible to message every participating device along a path without having to know its location, or its location relative to other devices (this is particularly a pressing issue when you've got one or more NATs present in the network, or when trying to locate appropriate tunnel endpoints).

A diagram should be added here showing I2NSF and NSIS

Why I2NSF is different than NSIS:

Why we belief I2NSF has a higher chance to be deployed than NSIS:

6. Summarized Requirements

The I2NSF framework should provide a set of standard interfaces that facilitate:

Moreover, an I2NSF must support different deployment scenarios:

The I2NSF framework should provide a standard set of interfaces that enable:

7. IANA Considerations

No IANA considerations exist for this document.

8. Security Considerations

The relationship between different actors define the security level for the different use cases and must be associated with administrative domains:

Virtualization applied to NSF environment (vNSF) generate several concerns in security, being one of the most relevant the attestation of the vNSF by the clients. A holistic analysis has been done in [NFVSEC].

9. Contributors

I2NSF is a group effort. The following people contributed actively to the initial use case text: Diego R. Lopez (Telefonica I+D), Xiaojun Zhuang (China Mobile), Minpeng Qi (China Mobile), Sumandra Majee (F5), Nic Leymann (Deutsche Telekom), Linda Dunbar (Huawei).

10. References

10.1. Normative References

[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, DOI 10.17487/RFC0791, September 1981.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.

10.2. Informative References

[I-D.dunbar-i2rs-discover-traffic-rules] Dunbar, L. and S. Hares, "An Information Model for Filter Rules for Discovery and Traffic for I2RS Filter-Based RIB", Internet-Draft draft-dunbar-i2rs-discover-traffic-rules-00, March 2015.
[I-D.hares-i2rs-auth-trans] Hares, S., Migault, D. and J. Halpern, "I2RS Security Related Requirements", Internet-Draft draft-hares-i2rs-auth-trans-05, August 2015.
[I-D.hares-i2rs-bnp-eca-data-model] Hares, S., Wu, Q., Tantsura, J. and R. White, "An Information Model for Basic Network Policy and Filter Rules", Internet-Draft draft-hares-i2rs-bnp-eca-data-model-00, July 2015.
[I-D.hares-i2rs-info-model-service-topo] Hares, S., Wu, W., Wang, Z. and J. You, "An Information model for service topology", Internet-Draft draft-hares-i2rs-info-model-service-topo-03, January 2015.
[I-D.ietf-i2rs-architecture] Atlas, A., Halpern, J., Hares, S., Ward, D. and T. Nadeau, "An Architecture for the Interface to the Routing System", Internet-Draft draft-ietf-i2rs-architecture-09, March 2015.
[I-D.ietf-i2rs-ephemeral-state] Haas, J. and S. Hares, "I2RS Ephemeral State Requirements", Internet-Draft draft-ietf-i2rs-ephemeral-state-02, September 2015.
[I-D.ietf-i2rs-problem-statement] Atlas, A., Nadeau, T. and D. Ward, "Interface to the Routing System Problem Statement", Internet-Draft draft-ietf-i2rs-problem-statement-06, January 2015.
[I-D.ietf-i2rs-pub-sub-requirements] Voit, E., Clemm, A. and A. Prieto, "Requirements for Subscription to YANG Datastores", Internet-Draft draft-ietf-i2rs-pub-sub-requirements-03, October 2015.
[I-D.ietf-i2rs-rib-data-model] Wang, L., Ananthakrishnan, H., Chen, M., amit.dass@ericsson.com, a., Kini, S. and N. Bahadur, "A YANG Data Model for Routing Information Base (RIB)", Internet-Draft draft-ietf-i2rs-rib-data-model-01, September 2015.
[I-D.ietf-i2rs-rib-info-model] Bahadur, N., Kini, S. and J. Medved, "Routing Information Base Info Model", Internet-Draft draft-ietf-i2rs-rib-info-model-07, September 2015.
[I-D.ietf-i2rs-traceability] Clarke, J., Salgueiro, G. and C. Pignataro, "Interface to the Routing System (I2RS) Traceability: Framework and Information Model", Internet-Draft draft-ietf-i2rs-traceability-03, May 2015.
[I-D.ietf-i2rs-usecase-reqs-summary] Hares, S. and M. Chen, "Summary of I2RS Use Case Requirements", Internet-Draft draft-ietf-i2rs-usecase-reqs-summary-01, May 2015.
[I-D.ietf-i2rs-yang-l2-network-topology] Dong, J. and X. Wei, "A YANG Data Model for Layer-2 Network Topologies", Internet-Draft draft-ietf-i2rs-yang-l2-network-topology-01, July 2015.
[I-D.ietf-i2rs-yang-network-topo] Clemm, A., Medved, J., Varga, R., Tkacik, T., Bahadur, N. and H. Ananthakrishnan, "A Data Model for Network Topologies", Internet-Draft draft-ietf-i2rs-yang-network-topo-01, June 2015.
[I-D.ietf-isis-yang-isis-cfg] Litkowski, S., Yeung, D., Lindem, A., Zhang, J. and L. Lhotka, "YANG Data Model for ISIS protocol", Internet-Draft draft-ietf-isis-yang-isis-cfg-02, March 2015.
[I-D.ietf-netconf-call-home] Watsen, K., "NETCONF Call Home and RESTCONF Call Home", Internet-Draft draft-ietf-netconf-call-home-06, May 2015.
[I-D.ietf-netconf-restconf] Bierman, A., Bjorklund, M. and K. Watsen, "RESTCONF Protocol", Internet-Draft draft-ietf-netconf-restconf-04, January 2015.
[I-D.ietf-netconf-restconf-collection] Bierman, A., Bjorklund, M. and K. Watsen, "RESTCONF Collection Resource", Internet-Draft draft-ietf-netconf-restconf-collection-00, January 2015.
[I-D.ietf-netconf-zerotouch] Watsen, K., Clarke, J. and M. Abrahamsson, "Zero Touch Provisioning for NETCONF Call Home (ZeroTouch)", Internet-Draft draft-ietf-netconf-zerotouch-02, March 2015.
[I-D.ietf-netmod-acl-model] Bogdanovic, D., Sreenivasa, K., Huang, L. and D. Blair, "Network Access Control List (ACL) YANG Data Model", Internet-Draft draft-ietf-netmod-acl-model-02, March 2015.
[I-D.ietf-netmod-routing-cfg] Lhotka, L. and A. Lindem, "A YANG Data Model for Routing Management", Internet-Draft draft-ietf-netmod-routing-cfg-19, May 2015.
[I-D.ietf-netmod-syslog-model] Wildes, C. and K. Sreenivasa, "SYSLOG YANG model", Internet-Draft draft-ietf-netmod-syslog-model-03, March 2015.
[I-D.ietf-ospf-yang] Yeung, D., Qu, Y., Zhang, J., Bogdanovic, D. and K. Sreenivasa, "Yang Data Model for OSPF Protocol", Internet-Draft draft-ietf-ospf-yang-00, March 2015.
[I-D.ietf-pcp-authentication] Wasserman, M., Hartman, S., Zhang, D. and T. Reddy, "Port Control Protocol (PCP) Authentication Mechanism", Internet-Draft draft-ietf-pcp-authentication-09, May 2015.
[I-D.ietf-pcp-optimize-keepalives] Reddy, T., Patil, P., Isomaki, M. and D. Wing, "Optimizing NAT and Firewall Keepalives Using Port Control Protocol (PCP)", Internet-Draft draft-ietf-pcp-optimize-keepalives-06, May 2015.
[I-D.ietf-pcp-proxy] Perreault, S., Boucadair, M., Penno, R., Wing, D. and S. Cheshire, "Port Control Protocol (PCP) Proxy Function", Internet-Draft draft-ietf-pcp-proxy-08, May 2015.
[I-D.ietf-sacm-architecture] Cam-Winget, N., Lorenzin, L., McDonald, I. and l. loxx@cisco.com, "Secure Automation and Continuous Monitoring (SACM) Architecture", Internet-Draft draft-ietf-sacm-architecture-03, March 2015.
[I-D.ietf-sacm-terminology] Waltermire, D., Montville, A., Harrington, D., Cam-Winget, N., Lu, J., Ford, B. and M. Kaeo, "Terminology for Security Assessment", Internet-Draft draft-ietf-sacm-terminology-06, February 2015.
[I-D.kini-i2rs-fb-rib-info-model] Kini, S., Hares, S., Dunbar, L., Ghanwani, A., Krishnan, R., Bogdanovic, D., Tantsura, J. and R. White, "Filter-Based RIB Information Model", Internet-Draft draft-kini-i2rs-fb-rib-info-model-01, July 2015.
[I-D.l3vpn-service-yang] Litkowski, S., Shakir, R., Tomotaki, L. and K. D'Souza, "YANG Data Model for L3VPN service delivery", Internet-Draft draft-l3vpn-service-yang-00, February 2015.
[I-D.liu-bess-mvpn-yang] Liu, Y. and F. Guo, "Yang Data Model for Multicast in MPLS/BGP IP VPNs", Internet-Draft draft-liu-bess-mvpn-yang-00, April 2015.
[I-D.shaikh-idr-bgp-model] Shaikh, A., D'Souza, K., Bansal, D. and R. Shakir, "BGP Model for Service Provider Networks", Internet-Draft draft-shaikh-idr-bgp-model-01, March 2015.
[I-D.shaikh-rtgwg-policy-model] Shaikh, A., Shakir, R., D'Souza, K. and C. Chase, "Routing Policy Configuration Model for Service Provider Networks", Internet-Draft draft-shaikh-rtgwg-policy-model-01, July 2015.
[I-D.tsingh-bess-pbb-evpn-yang-cfg] Tiruveedhula, K., Singh, T., Sajassi, A., Kumar, D. and L. Jalil, "YANG Data Model for PBB EVPN protocol", Internet-Draft draft-tsingh-bess-pbb-evpn-yang-cfg-00, March 2015.
[I-D.zhang-i2rs-l1-topo-yang-model] Zhang, X., Rao, B. and X. Liu, "A YANG Data Model for Layer 1 Network Topology", Internet-Draft draft-zhang-i2rs-l1-topo-yang-model-01, March 2015.
[I-D.zhdankin-idr-bgp-cfg] Alex, A., Patel, K., Clemm, A., Hares, S., Jethanandani, M. and X. Liu, "Yang Data Model for BGP Protocol", Internet-Draft draft-zhdankin-idr-bgp-cfg-00, January 2015.
[I-D.zhuang-bess-evpn-yang] Zhuang, S. and Z. Li, "Yang Model for Ethernet VPN", Internet-Draft draft-zhuang-bess-evpn-yang-00, December 2014.
[I-D.zhuang-bess-l3vpn-yang] Zhuang, S. and Z. Li, "Yang Data Model for BGP/MPLS IP VPNs", Internet-Draft draft-zhuang-bess-l3vpn-yang-00, December 2014.
[RFC2748] Durham, D., Boyle, J., Cohen, R., Herzog, S., Rajan, R. and A. Sastry, "The COPS (Common Open Policy Service) Protocol", RFC 2748, DOI 10.17487/RFC2748, January 2000.
[RFC2940] Smith, A., Partain, D. and J. Seligson, "Definitions of Managed Objects for Common Open Policy Service (COPS) Protocol Clients", RFC 2940, DOI 10.17487/RFC2940, October 2000.
[RFC3084] Chan, K., Seligson, J., Durham, D., Gai, S., McCloghrie, K., Herzog, S., Reichmeyer, F., Yavatkar, R. and A. Smith, "COPS Usage for Policy Provisioning (COPS-PR)", RFC 3084, DOI 10.17487/RFC3084, March 2001.
[RFC3303] Srisuresh, P., Kuthan, J., Rosenberg, J., Molitor, A. and A. Rayhan, "Middlebox communication architecture and framework", RFC 3303, DOI 10.17487/RFC3303, August 2002.
[RFC3304] Swale, R., Mart, P., Sijben, P., Brim, S. and M. Shore, "Middlebox Communications (midcom) Protocol Requirements", RFC 3304, DOI 10.17487/RFC3304, August 2002.
[RFC3483] Rawlins, D., Kulkarni, A., Bokaemper, M. and K. Chan, "Framework for Policy Usage Feedback for Common Open Policy Service with Policy Provisioning (COPS-PR)", RFC 3483, DOI 10.17487/RFC3483, March 2003.
[RFC3484] Draves, R., "Default Address Selection for Internet Protocol version 6 (IPv6)", RFC 3484, DOI 10.17487/RFC3484, February 2003.
[RFC4080] Hancock, R., Karagiannis, G., Loughney, J. and S. Van den Bosch, "Next Steps in Signaling (NSIS): Framework", RFC 4080, DOI 10.17487/RFC4080, June 2005.
[RFC4261] Walker, J. and A. Kulkarni, "Common Open Policy Service (COPS) Over Transport Layer Security (TLS)", RFC 4261, DOI 10.17487/RFC4261, December 2005.
[RFC4949] Shirey, R., "Internet Security Glossary, Version 2", FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007.
[RFC5189] Stiemerling, M., Quittek, J. and T. Taylor, "Middlebox Communication (MIDCOM) Protocol Semantics", RFC 5189, DOI 10.17487/RFC5189, March 2008.
[RFC5277] Chisholm, S. and H. Trevino, "NETCONF Event Notifications", RFC 5277, DOI 10.17487/RFC5277, July 2008.
[RFC5539] Badra, M., "NETCONF over Transport Layer Security (TLS)", RFC 5539, DOI 10.17487/RFC5539, May 2009.
[RFC5973] Stiemerling, M., Tschofenig, H., Aoun, C. and E. Davies, "NAT/Firewall NSIS Signaling Layer Protocol (NSLP)", RFC 5973, DOI 10.17487/RFC5973, October 2010.
[RFC6022] Scott, M. and M. Bjorklund, "YANG Module for NETCONF Monitoring", RFC 6022, DOI 10.17487/RFC6022, October 2010.
[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011.
[RFC6243] Bierman, A. and B. Lengyel, "With-defaults Capability for NETCONF", RFC 6243, DOI 10.17487/RFC6243, June 2011.
[RFC6436] Amante, S., Carpenter, B. and S. Jiang, "Rationale for Update to the IPv6 Flow Label Specification", RFC 6436, DOI 10.17487/RFC6436, November 2011.
[RFC6470] Bierman, A., "Network Configuration Protocol (NETCONF) Base Notifications", RFC 6470, DOI 10.17487/RFC6470, February 2012.
[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012.
[RFC6639] King, D. and M. Venkatesan, "Multiprotocol Label Switching Transport Profile (MPLS-TP) MIB-Based Management Overview", RFC 6639, DOI 10.17487/RFC6639, June 2012.
[RFC6887] Wing, D., Cheshire, S., Boucadair, M., Penno, R. and P. Selkirk, "Port Control Protocol (PCP)", RFC 6887, DOI 10.17487/RFC6887, April 2013.
[RFC7223] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 7223, DOI 10.17487/RFC7223, May 2014.
[RFC7225] Boucadair, M., "Discovering NAT64 IPv6 Prefixes Using the Port Control Protocol (PCP)", RFC 7225, DOI 10.17487/RFC7225, May 2014.
[RFC7277] Bjorklund, M., "A YANG Data Model for IP Management", RFC 7277, DOI 10.17487/RFC7277, June 2014.
[RFC7317] Bierman, A. and M. Bjorklund, "A YANG Data Model for System Management", RFC 7317, DOI 10.17487/RFC7317, August 2014.

Authors' Addresses

Susan Hares Huawei 7453 Hickory Hill Saline, MI 48176 USA EMail: shares@ndzh.com
Antonio Pastor Telefonica I+D Don Ramon de la Cruz, 82 Madrid, 28006 Spain EMail: antonio.pastorperales@telefonica.com
Ke Wang China Mobile 32 Xuanwumenxi Ave,Xicheng District Beijing, 100053 China EMail: wangkeyj@chinamobile.com
Dacheng Zhang Beijing, China EMail: dacheng.zdc@aliabab-inc.com
Myo Zarny Goldman Sachs 30 Hudson Street Jersey City, NJ 07302 USA EMail: myo.zarny@gs.com