I2NSF Registration Interface Data Model

A number of virtual network security function instances typically exist in Interface to Network Security Functions (I2NSF) framework . 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 ) and a YANG data model (see ) for the I2NSF Registration Interface 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.

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 .

This document uses the following terms defined in , , , , , and Network Security Function (NSF): A function that is responsible for specific treatment of received packets. A Network Security Function can act at various layers of a protocol stack (e.g., at the network layer or other OSI layers). Sample Network Security Service Functions are as follows: Firewall, Intrusion Prevention/Detection System (IPS/IDS), Deep Packet Inspection (DPI), Application Visibility and Control (AVC), network virus and malware scanning, sandbox, Data Loss Prevention (DLP), Distributed Denial of Service (DDoS) mitigation and TLS proxy. Advanced Inspection/Action: As like the I2NSF information model for NSF facing interface , Advanced Inspection/Action means that a security function calls another security function for further inspection based on its own inspection result. NSF Profile (NSF Capability Information): NSF Capability Information specifies the inspection capabilities of the associated NSF instance. Each NSF instance has its own NSF Capability Information to specify the type of security service it provides and its resource capacity etc. Data Model: A data model is a representation of concepts of interest to an environment in a form that is dependent on data repository, data definition language, query language, implementation language, and protocol. Information Model: An information model is a representation of concepts of interest to an environment in a form that is independent of data repository, data definition language, query language, implementation language, and protocol.

Registering NSF instances from Developer's Management System: Depending on system's security requirements, it may require some NSFs by default. In this case, DMS creates these default NSF instances and notifies Security Controller of those NSF instances via Registration Interface. Requesting NSF instances with required security capabilities: I2NSF users request security policies to Security Controller, and enforcing the security policies requires a set of security capabilities. In addition, when an NSF triggers another type of NSF(s) for more advanced security inspection of a given traffic, some security capabilities are also required to perform the advanced security inspection. If Security Controller has no NSF instance registered with the requried capabilities, Security Controller requests DMS for new NSF instances that can provide the required capabilities. Once receiving this request, DMS could first search its inventory for NSF instances with the required capabilities. If DMS fails to find any NSF instance, it creates new NSF instances with the required security capabilities and registers the NSF instances to Security Controller. Deleting unnecessary NSF instances: In I2NSF framework, users decide which security service is unnecessary in the system. If there exist any unused NSF instances, then we should delete the existing instances by requesting DMS via registration interface. Updating NSF instances: After an NSF instance is registered into I2NSF framework, some changes may happen on the capability of the NSF instance. These changes should be informed to Security Controller. For this, after updating some NSF instances, DMS notifies Security Controller of the update via registration interface.

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.

As illustrated in , 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.

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.

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 , the I2NSF capability interface can conduct controlling and monitoring the new registered NSF instance.

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) , 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).

NSF Profile basically describes the inspection capabilities of an NSF instance. In , we show capability objects of an NSF instance. Following the information model of NSF capabilities defiend in , 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 .

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 , 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.

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. and 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 and specifies a set of access-types to be permitted and to be denied by each role-id.

This section provides an overview of the high level YANG.

A simplified graphical representation of the data model is used in this section. The meaning of the symbols used in the following diagrams is as follows: Brackets "[" and "]" enclose list keys. Abbreviations before data node names: "rw" means configuration (read-write) and "ro" state data (read-only). Symbols after data node names: "?" means an optional node and "*" denotes a "list" and "leaf-list". Parentheses enclose choice and case nodes, and case nodes are also marked with a colon (":"). Ellipsis ("...") stands for contents of subtrees that are not shown.

Each of these sections mirror sections of .

This section expands the i2nsf-regs-req in .

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.

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

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.

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

In , ietf-i2nsf-capability refers module ietf-i2nsf-capability in . We add the performance capability because it is absent in and

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

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

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

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.

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

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

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 .

file "ietf-i2nsf-regs-interface@2018-07-26.yang" module ietf-i2nsf-regs-interface { namespace "urn:ietf:params:xml:ns:yang:ietf-i2nsf-regs-interface"; prefix regs-interface; import ietf-inet-types{ prefix inet; } organization "IETF I2NSF (Interface to Network Security Functions) Working Group"; contact "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 "; description "It defines a YANG data module for Registration Interface."; revision "2018-07-26"{ description "The second revision"; reference "draft-ietf-i2nsf-capability-data-model-01"; } list interface-container{ key "interface-name"; description "i2nsf-reg-interface-container"; leaf interface-name{ type string; description "interface name"; } container i2nsf-regs-req { description "The capability information of newly created NSF to notify its capability to Security Controller"; container nsf-capability-information { description "nsf-capability-information"; uses i2nsf-nsf-capability-information; } container nsf-access-info { description "nsf-access-info"; uses i2nsf-nsf-access-info; } container ietf-netmod-acl-model{ description "netmod-acl-model"; uses ietf-netmod-acl-model; } } container i2nsf-instance-mgnt-req { description "Required information for instanciation-request, deinstanciation-request and updating-request"; leaf req-level { type uint16; description "req-level"; } leaf req-id { type uint64; mandatory true; description "req-id"; } choice req-type { description "req-type"; case instanciation-request { description "instanciation-request"; container in-nsf-capability-information { description "nsf-capability-information"; uses i2nsf-nsf-capability-information; } } case deinstanciation-request { description "deinstanciation-request"; container de-nsf-access-info { description "nsf-access-info"; uses i2nsf-nsf-access-info; } } case updating-request { description "updating nsf's information"; container update-nsf-capability-information { description "nsf-capability-information"; uses i2nsf-nsf-capability-information; } } } } } grouping i2nsf-nsf-performance-caps { description "NSF performance capailities"; container processing{ description "processing info"; leaf processing-average{ type uint16; description "processing-average"; } leaf processing-peak{ type uint16; description "processing peak"; } } container bandwidth{ description "bandwidth info"; container inbound{ description "inbound"; leaf inbound-average{ type uint16; description "inbound-average"; } leaf inbound-peak{ type uint16; description "inbound-peak"; } } container outbound{ description "outbound"; leaf outbound-average{ type uint16; description "outbound-average"; } leaf outbound-peak{ type uint16; description "outbound-peak"; } } } } grouping i2nsf-nsf-capability-information { description "Detail information of an NSF"; container performance-capability { uses i2nsf-nsf-performance-caps; description "performance-capability"; } container i2nsf-capability { description "It refers draft-ietf-i2nsf-capability-data-model-01.txt later"; } } grouping ietf-netmod-acl-model { description "Detail information"; container role-based-acl { description "It refers draft-ietf-netmod-acl-model-19.txt later"; } } grouping i2nsf-nsf-access-info { description "NSF access information"; leaf nsf-address { type inet:ipv4-address; mandatory true; description "nsf-address"; } leaf nsf-port-address { type inet:port-number; description "nsf-port-address"; } } }

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                        Requirement: Registering the IDS NSF with VoIP/VoLTE security capability using Registration interface.
                    
                    
                        Here is the configuration xml for this Registration Interface:
                    
                    
                    
            
              
                
                  
                
                
                
                  
                    
                      
                       1
                        
                         
                          
                           true
                           
                            ids-service
                           
                          
                          
                           true
                           
                            
                             ips-service
                            
                           
                          
                         
                       
                      
                    
                    
                      
                       1000
                       5000
                      
                      
                       
                        1000
                        5000
                       
                       
                        1000
                        5000
                       
                      
                    
                  
                  
                   10.0.0.1
                   145
                  
                
                
              
            
                    ]]>



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

    
        
            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).