Internet Working Group W. Xu Y. Jiang C. Zhou Huawei Internet Draft Intended status: Standards Track Expires: January 2015 July 4, 2014 Data Models for Network Functions Virtualization draft-xjz-opsawg-nfvmodel-00.txt Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html This Internet-Draft will expire on January 4, 2015. Copyright Notice Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of Xu, et al Expires January 4, 2015 [Page 1] Internet-Draft NFV Data Models July 2014 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Abstract Network Functions Virtualisation (NFV) is a technology of virtualizing network functionalities. In NFV management and orchestration a flexible model is needed for the description of its information elements. This document provides some YANG data models for Network Functions Virtualization (NFV). Table of Contents 1. Introduction .............................................. 3 2. Conventions used in this document ......................... 3 3. Terminology ............................................... 3 4. The Design of the VNF Data Model .......................... 4 5. Data Model of Virtualization Deployment Unit (VDU) ........ 4 5.1. VDU Module Structure ................................... 5 5.2. VDU YANG Module ........................................ 6 6. Data Model of Deployment Flavor .......................... 15 6.1. Deployment Flavor Module Structure .................... 15 6.2. Deployment Flavor YANG Module ......................... 15 7. Data Model of Virtual Link Descriptor (VLD) .............. 19 7.1. VLD Module Structure .................................. 19 7.2. VLD YANG Module ....................................... 19 8. Data Model of Virtual Network Function Descriptor (VNFD) . 23 8.1. VNFD Module Structure ................................. 23 8.2. VNFD YANG Module ...................................... 25 9. Data Model of Virtual Network Function instantiation(VNFI) 35 5.1. VNF instance Module Structure ......................... 35 5.2. VNF instance YANG Module .............................. 35 10. Security Considerations .................................. 41 11. IANA Considerations ...................................... 41 12. References ............................................... 41 12.1. Normative References ............................... 41 12.2. Informative References ............................. 41 13. Contributors ............................................. 42 14. Acknowledgments .......................................... 42 Expires January 4,2015 [Page 2] Internet-Draft NFV Data Models July 2014 1. Introduction YANG [RFC6020] is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF) [RFC6241]. A small set of built-in data types are defined in [RFC6020], a collection of common data types are further defined in [RFC6991]. Network Functions Virtualisation (NFV), is a technology initiated in ETSI, which tries to define a standard way for some network equipments to be virtualized in COTS IT servers, switches and storage. Therefore, with the introduction of the NFV technology, the traditional physical network device could be implemented using the Virtualized Network Function (VNF). In NFV management and orchestration a flexible model is needed for the description of its information elements. This document defines a YANG data model for Network Functions Virtualization (NFV). Most of the concepts in this document are borrowed from [GS-002], [GS-003] and [GS-MANO], and they may be changed as the work is still in progress. 2. Conventions used in this document 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 Network Function (NF): is a functional building block within an operator's network infrastructure, which has well defined external interfaces and a well defined functional behaviour. Virtual Machine (VM): a virtualized computation environment which behaves very much like a physical computer/server. Virtualised Network Function (VNF): is a network function that has been virtualized and can be offered as a network service or be part of a service comprised of a set of virtualized network functions and/or non-virtualized network functions. VNF Descriptor (VNFD): A configuration template that describes a VNF in terms of its deployment and operational behaviour, and is used in Expires January 4,2015 [Page 3] Internet-Draft NFV Data Models July 2014 the process of VNF on-boarding and managing the lifecycle of a VNF instance VNF Instance: a run-time instantiation of the VNF, resulting from completing the instantiation of VNF, using the VNF deployment and operational information captured in the VNFD, as well as additional run-time instance-specific information and constraints. Virtualization Deployment Unit (VDU): a construct that can be used in an information model, supporting the description of the deployment and operational behaviour of a subset of a VNF, or the entire VNF if it was not componentized in subsets. 4. The Design of the VNF Data Model The data model for VNFDs presented in this document uses a list of VNFDs. Each VNFD in the list is identified by its id. A VNFD include a list of Deployment Flavour (DF). This property is achieved by ''leafref'' to a template of deployment flavor, which other YANG modules should used when they need to reference a deployment flavor. A Deployment Flavour include a list of Virtualization Deployment Unit(VDU). A VNFD also include a list of connection points, each of which describes an external interface exposed by this VNF. Furthermore, connection points should be attached to a Virtual Link upon VNF initialization. This procedure is attained by ''leafref'' to a template of Virtual Link Descriptor (VLD). VNFI describes the instantiation operation of a specific VNFD. A ''leafref'' was used to reference a VNFD in the data model for VNFI. 5. Data Model of Virtualization Deployment Unit (VDU) VDU models the deployment and operational behavior of a subset of a VNF instance, or the entire VNF instance if it was not componentized in subsets. It specifies various resource requirements, such as CPU, memory, storage and etc. It can also specify the VNF operating behaviors, which could be embedded in scripts when the VNF instance is initialized, terminated or shut down. Expires January 4,2015 [Page 4] Internet-Draft NFV Data Models July 2014 5.1. VDU Module Structure module: ietf-vdus +--rw vdus +--rw vdu* [id] +--rw id yang:uuid +--rw instance_num? string +--rw vm_image? string +--rw resource | +--rw cpu | | +--rw vCPU_num? uint32 | | +--rw vCPU_spec* [name] | | +--rw name string | | +--rw description? string | | +--rw value? uint32 | +--rw memory | | +--rw memory_size? uint32 | | +--rw memory_spec* [name] | | +--rw name string | | +--rw description? string | | +--rw value? uint32 | +--rw disk | | +--rw disk_size? uint32 | | +--rw disk_KQI* [name] | | +--rw name string Expires January 4,2015 [Page 5] Internet-Draft NFV Data Models July 2014 | | +--rw description? string | | +--rw value? uint32 | +--rw vnic | +--rw vnic_num? uint32 +--rw workflow_script +--rw init? string +--rw terminate? string +--rw graceful-shutdown? string 5.2. VDU YANG Module module ietf-vdus { namespace "urn:ietf:params:xml:ns:yang:ietf-vdus"; prefix "vdu"; import ietf-yang-types { prefix yang; } organization ""; contact "TBD"; description "This module defines a VNF Deployment Unit. Copyright (c) 2014 IETF Trust and the persons Expires January 4,2015 [Page 6] Internet-Draft NFV Data Models July 2014 identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision "2014-05-18" { description "Initial version"; reference "RFC XXXX"; } container vdus { description "Vdus used in a vnfd"; list vdu { Expires January 4,2015 [Page 7] Internet-Draft NFV Data Models July 2014 key id; description "Vdu key"; leaf id { type yang:uuid; description "VDU ID"; } leaf instance-num { type uint16; description "Number of instances of the said VDU which shall be instantiated"; } leaf vm-image { type string; description "Reference to a VM image"; } container resource { Expires January 4,2015 [Page 8] Internet-Draft NFV Data Models July 2014 description "The required resource"; container cpu { description "The required computation resource"; leaf vCPU_num { type uint32; description "The number of virtual CPU units"; } list vCPU-spec { key "name"; description "Processor characteristics for the VDU"; leaf name { type string; description "Name of vCPU-spec"; } Expires January 4,2015 [Page 9] Internet-Draft NFV Data Models July 2014 leaf description { type string; description "Description of vCPU-spec"; } leaf value { type uint32; description "Value of vCPU-spec"; } } } container memory { description "The required memory resource"; leaf memory_size { type uint32; description "Memory size, unit:MBytes"; } Expires January 4,2015 [Page 10] Internet-Draft NFV Data Models July 2014 list memory-spec { key name; description "Memory characteristics for the VDU"; leaf name { type string; description "Name of memory-spec"; } leaf description { type string; description "Description of memory-spec"; } leaf value { type uint32; description "Value of memory-spec"; } Expires January 4,2015 [Page 11] Internet-Draft NFV Data Models July 2014 } } container disk { description "The required storage resource"; leaf disk-size { type uint32; description "Virtual storage size, unit:MBytes"; } list disk-KQI { key name; description "Storage characteristics in the VDU"; leaf name { type string; description "Name of disk-KQI"; } Expires January 4,2015 [Page 12] Internet-Draft NFV Data Models July 2014 leaf description { type string; description "Description of disk-KQI"; } leaf value { type uint32; description "Value of disk-KQI"; } } } container vnic { description "Virtual network interface card (vnic) resource"; leaf vnic-num { type uint32; description "The total number of virtual vnic"; } Expires January 4,2015 [Page 13] Internet-Draft NFV Data Models July 2014 } } container workflow-script { description "VDU workflow script"; leaf init { type string; description "VDU initialization script"; } leaf terminate { type string; description "VDU termination script"; } leaf graceful-shutdown { type string; description "VDU graceful shutdown script"; } } Expires January 4,2015 [Page 14] Internet-Draft NFV Data Models July 2014 } } } 6. Data Model of Deployment Flavor A deployment flavor is a template that describes a specific deployment of a Virtualised Network Function supporting required capacity and performance. It refers to a set of VDUs which provide the deployment and operational behavior. 6.1. Deployment Flavor Module Structure module: ietf-dfs +--rw dfs +--rw df* [df-id] +--rw df-id yang:uuid +--rw license-info string +--rw pricing_info string +--rw vdu* [vdu-id] +--rw vdu-id leafref 6.2. Deployment Flavor YANG Module module ietf-dfs { namespace "urn:ietf:params:xml:ns:yang:ietf-dfs"; Expires January 4,2015 [Page 15] Internet-Draft NFV Data Models July 2014 prefix "df"; import ietf-yang-types { prefix yang; } import ietf-vdus { prefix vdu; } organization ""; contact "TBD"; description "This module defines a deployment flavor descriptor. Copyright (c) 2014 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents Expires January 4,2015 [Page 16] Internet-Draft NFV Data Models July 2014 (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision "2014-05-18" { description "Initial version"; reference "RFC XXXX"; } container dfs { description "Deployment Flavors"; list df { key df-id; description "Deployment flavor key"; leaf df-id { type yang:uuid; description "Deployment flavor ID"; Expires January 4,2015 [Page 17] Internet-Draft NFV Data Models July 2014 } leaf license-info { type string; description "Software licenses required for supporting this deployment flavour."; } leaf pricing_info { type string; description "Pricing information required for supporting this deployment flavour."; } list vdu { key vdu-id; description "Refer to a VDU used for this deployment flavor"; leaf vdu-id { type leafref { path "/vdu:vdus/vdu:vdu/vdu:id"; } Expires January 4,2015 [Page 18] Internet-Draft NFV Data Models July 2014 description "Vdu ID"; } } } } } 7. Data Model of Virtual Link Descriptor (VLD) VLD describes the resource requirements that are needed for a virtualization link. 7.1. VLD Module Structure module: ietf-vlds +--rw vlds +--rw vld* [id] +--rw id yang:uuid +--rw vendor? string +--rw version? string +--rw number_of_enpoints? uint32 +--rw virtual-link-type? enumeration 7.2. VLD YANG Module module ietf-vlds { Expires January 4,2015 [Page 19] Internet-Draft NFV Data Models July 2014 namespace "urn:ietf:params:xml:ns:yang:ietf-vlds"; prefix "vld"; import ietf-yang-types { prefix yang; } organization ""; contact "TBD"; description "This module defines a virtual link descritor. Copyright (c) 2014 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). Expires January 4,2015 [Page 20] Internet-Draft NFV Data Models July 2014 This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision "2014-05-18" { description "Initial version"; reference "RFC XXXX"; } container vlds { description "Virtual Link Descriptors"; list vld { key id; description "VLD Key"; leaf id { type yang:uuid; description "VLD ID"; } Expires January 4,2015 [Page 21] Internet-Draft NFV Data Models July 2014 leaf vendor { type string; description "Vendor generating this VLD"; } leaf version { type string; description "Version of this VLD"; } leaf number-of-endpoints { type uint32; description "Number of endpoints available on this VLD"; } leaf virtual-link-type { type enumeration { enum "ELine"; enum "ELAN"; enum "ETree"; } Expires January 4,2015 [Page 22] Internet-Draft NFV Data Models July 2014 description "Virtual network link type mandated by the VNF vendor between two or more connection points"; } } } } 8. Data Model of Virtual Network Function Descriptor (VNFD) VNFD describes the deployment and operational behavior of a VNF. The main objective of VNF modeling will include: - Basic VNF attributes: The core information, such as VNF name, version, function description. - Deployment attributes: It specifies the infrastructure resource requirements in case of VNF deployment, such as virtual CPU, memory and disk requirements. It usually refer to a set of deployment flavor, which provide the detail requirement. It also specifies the workflow during the VNF initialization, termination, graceful shutdown. - Interface attributes: It represents a set of external interfaces exposed by this VNF, Here Connection-point was used as a term to express those interfaces, Each connection-point will refer to a virtualization link. - Automatic scale policy attributes: It represents automatic scale policy meta data, which include the criteria parameter,action-type, and etc. 8.1. VNFD Module Structure module: ietf-vnfds +--rw vnfds +--rw vnfd* [id] Expires January 4,2015 [Page 23] Internet-Draft NFV Data Models July 2014 +--rw name? string +--rw id yang:uuid +--rw description? string +--rw vendor? string +--rw descriptor-version? string +--rw version? string +--rw deploy-flavors | +--rw deploy-flavor-id* leafref +--rw workflow_script | +--rw init? string | +--rw terminate? string | +--rw graceful-shutdown? string +--rw connection-points | +--rw connection-point* [id] | +--rw id yang:uuid | +--rw name? string +--rw monitor-paras | +--rw name* enumeration +--rw auto-scale-policies +--rw auto-scale-policy* [policy-id] +--rw policy-id string +--rw criteria | +--rw criterion* [monitor-para-name] | +--rw monitor-para-name leafref Expires January 4,2015 [Page 24] Internet-Draft NFV Data Models July 2014 | +--rw expression? enumeration +--rw actions +--rw action* [action-name] +--rw action-name enumeration 8.2. VNFD YANG Module module ietf-vnfds { namespace "urn:ietf:params:xml:ns:yang:ietf-vnfds"; prefix "vnfd"; import ietf-yang-types { prefix yang; } import ietf-dfs { prefix df; } organization ""; contact "TBD"; description Expires January 4,2015 [Page 25] Internet-Draft NFV Data Models July 2014 "This module defines a template for other YANG modules. Copyright (c) 2014 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision "2014-05-18" { description "Initial version"; reference "RFC XXXX"; } container vnfds { description Expires January 4,2015 [Page 26] Internet-Draft NFV Data Models July 2014 "vnfd configuration parameters."; list vnfd { key id; description "The list of vnfd configuration parameters."; leaf name { type string; description "The name of the vnf descriptor."; } leaf id { type yang:uuid; description "The UUID of the vnf descriptor."; } leaf description { type string; description "The description of the vnf descriptor."; } Expires January 4,2015 [Page 27] Internet-Draft NFV Data Models July 2014 leaf vendor { type string; description "The vendor of the vnf descriptor."; } leaf descriptor-version { type string; description "The version of the vnf descriptor."; } leaf version { type string; description "The version of the vnf software."; } container deploy-flavors { description "Deployment Flavor configuration parameters."; leaf-list deploy-flavor-id { Expires January 4,2015 [Page 28] Internet-Draft NFV Data Models July 2014 type leafref { path "/df:dfs/df:df/df:df-id"; } description "The list of deployment flavor configuration parameters."; } } container workflow_script { description "The VDU workflow including the functional script. "; leaf init { type string; description "The VDU initiation script."; } leaf terminate { type string; description "The VDU termination script."; } Expires January 4,2015 [Page 29] Internet-Draft NFV Data Models July 2014 leaf graceful-shutdown { type string; description "The VDU graceful shutdown script."; } } container connection-points { description "It describes an external interface exposed by this VNF enabling connection with a VL.."; list connection-point { key id; description "The connection point exposed by the VNF enabling connection with a VLD."; leaf id { type yang:uuid; description "The unique identifier of connection point."; } leaf name { Expires January 4,2015 [Page 30] Internet-Draft NFV Data Models July 2014 type string; description "The name of connection point."; } } } container monitor-paras { description "Monitoring parameter, which can be tracked for this VNF."; leaf-list name { type enumeration { enum cpu-utili; enum memory-consumption; enum bandwidth-consumption; enum calls-per-secon; enum number-of-subscriber; enum num-of-rules; enum flows-per-second; } description "A list of monitor parameters."; Expires January 4,2015 [Page 31] Internet-Draft NFV Data Models July 2014 } } container auto-scale-policies { description "The policy of automatic scale in/out."; list auto-scale-policy { key policy-id; description "The unique identifier of automatic scale policy."; leaf policy-id { type string; } container criteria { description "The auto-scale criteria parameter. Note that the default logical operation among these rules is 'OR'."; list criterion { key monitor-para-name; description "A list of rules"; Expires January 4,2015 [Page 32] Internet-Draft NFV Data Models July 2014 leaf monitor-para-name { type leafref { path "../../../../../monitor-paras/name"; } description "The name of monitor parameter."; } leaf expression { type enumeration { enum "eq"; enum "neq"; enum "lt"; //less than enum "gt"; //greater than } description "The logical criteria expression."; } } } container actions { description Expires January 4,2015 [Page 33] Internet-Draft NFV Data Models July 2014 "Action configuration parameters."; list action { key action-name; description "A list of configured action."; leaf action-name { type enumeration { enum "scale-out"; enum "scale-in"; } description "The type of action."; } } } } } } } } Expires January 4,2015 [Page 34] Internet-Draft NFV Data Models July 2014 9. Data Model of Virtual Network Function instantiation(VNFI) VNFI describes the instantiate operation of a specific VNFD. It specifies the identifier of VNFD being instantiating, and corresponding parameters, such as deployment flavor, a number of interfaces exposed outside the VNF, automatic scale policy data. 5.1. VNF instance Module Structure The data model for VNF instance has the following structure: module: ietf-vnfis +--rw vnfis +--rw vnfi* [id] +--rw id uint32 +--rw vnfd-id? leafref +--rw flavor-id? leafref +--rw external-attachments | +--rw external-attachment* [connection-point-id] | +--rw connection-point-id leafref | +--rw virtual-link-id? leafref +--rw scale-policy {auto-scale}? | +--rw policy-id? leafref | +--rw criteria-value* uint32 | +--rw target-flavor-id? leafref 5.2. VNF instance YANG Module module ietf-vnfis { Expires January 4,2015 [Page 35] Internet-Draft NFV Data Models July 2014 namespace "urn:ietf:params:xml:ns:yang:ietf-vnfis"; prefix "vnfi"; import ietf-vnfds { prefix vnfd; } import ietf-vlds { prefix vld; } import ietf-dfs { prefix df; } organization ""; contact "TBD"; description "This module contains YANG definitions for managing VNF instance. Copyright (c) 2014 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or Expires January 4,2015 [Page 36] Internet-Draft NFV Data Models July 2014 without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision "2014-05-18" { description "Initial version"; reference "RFC XXXX"; } // feature statements feature auto-scale { description "Support auto scaling."; } container vnfis { description "VNF instances configuration parameters."; Expires January 4,2015 [Page 37] Internet-Draft NFV Data Models July 2014 list vnfi { key id; description "The list of VNF instance configuration parameters."; leaf id { type uint32; description "the id of VNF instance."; } leaf vnfd-id { type leafref { path "/vnfd:vnfds/vnfd:vnfd/vnfd:id"; } description "VNF descriptor ID"; } leaf flavor-id { type leafref { path "/vnfd:vnfds/vnfd:vnfd/vnfd:deploy- flavors/vnfd:deploy-flavor-id"; } description "VNF flavor ID"; Expires January 4,2015 [Page 38] Internet-Draft NFV Data Models July 2014 } container external-attachments { list external-attachment { key connection-point-id; leaf connection-point-id { type leafref { path "/vnfd:vnfds/vnfd:vnfd/vnfd:connection- points/vnfd:connection-point/vnfd:id"; } description "VNF connection point ID to be attached with a virtual link."; } leaf virtual-link-id { type leafref { path "/vld:vlds/vld:vld/vld:id"; } description "virtual link ID attached to the VNF connection point"; } } } container scale-policy { Expires January 4,2015 [Page 39] Internet-Draft NFV Data Models July 2014 if-feature auto-scale; leaf policy-id { type leafref { path "/vnfd:vnfds/vnfd:vnfd/vnfd:auto-scale- policies/vnfd:auto-scale-policy/vnfd:policy-id"; } description "auto scaling policy ID"; } leaf-list criteria-value { type uint32; description "A set of criteria value in the policy rules"; } leaf target-flavor-id { type leafref { path "/df:dfs/df:df/df:df-id"; } description "The target deployment flavor ID"; } Expires January 4,2015 [Page 40] Internet-Draft NFV Data Models July 2014 } } } } 10. Security Considerations TBD. 11. IANA Considerations TBD. 12. References 12.1. Normative References [RFC6020] Schoenwaelder,J., RFC 6020, YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF), 2010 [RFC6991] Schoenwaelder,J.,RFC 6991, Common YANG Data Types, 2013 12.2. Informative References [GS-002] ETSI GS NFV 002, Network Functions Virtualisation (NFV) - Architectural Framework, 2013 [GS-003] ETSI GS NFV 003, Network Functions Virtualisation (NFV) - Terminology for Main Concepts in NFV, 2013 [GS-MANO] ETSI ISG NFV, "Network Function Virtualization (NFV) Management and Orchestration", NFV-MAN001 (work in progress), May 2014 Xu, W., Jiang, Y., Zhou, C., draft-xjz-nfv-model-problem-statement-00, Work in progress, 2013 Expires January 4,2015 [Page 41] Internet-Draft NFV Data Models July 2014 13. Contributors The authors would like to thank Mehmet Ersue who made a contribution to this document. Mehmet Ersue mehmet.ersue@nsn.com 14. Acknowledgments The authors would like to thank ETSI for the production of the NFV documents which is the basis of this draft. And we thank Mehmet Ensue and Min Zha for their valuable discussions. Expires January 4,2015 [Page 42] Internet-Draft NFV Data Models July 2014 Authors' Addresses Weiping Xu Huawei Technologies Co., Ltd. Bantian, Longgang district Shenzhen 518129, China Email: xuweiping@huawei.com Yuanlong Jiang Huawei Technologies Co., Ltd. Bantian, Longgang district Shenzhen 518129, China Email: jiangyuanlong@huawei.com Cathy Zhou Huawei Technologies Co., Ltd. Bantian, Longgang district Shenzhen 518129, China Email: cathy.zhou@huawei.com Expires January 4,2015 [Page 43]