Internet Engineering Task Force C. Chen Internet Draft Ericsson Intended status: Standards Track A. Pan Expires: June 2018 Ericsson December 28, 2017 Yang Data Model for Cloud Native 5G Core structure draft-chin-nfvrg-cloud-5g-core-structure-yang-00.txt Abstract In 5G core network, all network functions are componentized, virtualized and grouped into VNF. Network management system will manage the functions based on VNF. This document presents YANG model proposal on overall structure of cloud native 5G core network. The structure is itself represented as an example YANG model, with all of the related component models logically organized in a way that is operationally intuitive, but this model is not expected to be implemented. The identified component modules are expected to be defined and implemented. Status of this Memo This Internet-Draft is submitted 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 Chen Expires June 28, 2018 [Page 1] Internet-Draft 5G Core Structure Yang Data Model December 2017 This Internet-Draft will expire on February 28, 2009. Copyright Notice Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction ................................................ 2 1.1. Terminology ............................................ 2 1.2. Tree Diagrams .......................................... 3 1.3. Definition of terms ..................................... 4 2. Overview .................................................... 4 2.1. Background ............................................. 4 2.2. Management Structure .................................... 5 2.3. Model Proposal ......................................... 7 3. YANG Module ................................................. 8 4. Security Considerations ..................................... 13 5. IANA Considerations ........................................ 14 6. Normative References........................................ 14 1. Introduction In Cloud native 5G core network, the control and user plane functionalities are separated into NFs. Some NFs can be grouped in one VNF. From the NBI's view, network management system will manage the network based on VNF. This document will define the YANG of 5G core network management top-level structure. 1.1. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and Chen Expires June 28, 2018 [Page 2] Internet-Draft 5G Core Structure Yang Data Model December 2017 "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119]. The following terms are used within this document: The following terms are defined in [RFC6241] and are not redefined here: o client o configuration data o server o state data The following terms are defined in [RFC6020] and are not redefined here: o augment o data model o data node o presence container 1.2. Tree Diagrams A simplified graphical representation of the data model is used in this document. The meaning of the symbols in these diagrams is as follows: o Brackets "[" and "]" enclose list keys. o Abbreviations before data node names: "rw" means configuration (read-write), and "ro" means state data (read-only). o Symbols after data node names: "?" means an optional node, "!" means a presence container, and "*" denotes a list and leaf-list. o Parentheses enclose choice and case nodes, and case nodes are also marked with a colon (":"). o Ellipsis ("...") stands for contents of subtrees that are not shown. Chen Expires June 28, 2018 [Page 3] Internet-Draft 5G Core Structure Yang Data Model December 2017 1.3. Definition of terms CP: Control Plane UP: User Plane NSSF: Network Slice Selection Function AUSF: Authentication Server Function AMF: Core Access and Mobility Management Function DN: Data network SDSF: Structured Data Storage network function UDSF: Unstructured Data Storage network function NEF: Network Exposure Function NRF: NF Repository Function PCF: Policy Control function SMF: Session Management Function UDM: Unified Data Management UPF: User plane Function AF: Application Function UE: User Equipment (R)AN: (Radio) Access Network 2. Overview 2.1. Background Currently, 3GPP defined the three key technologies on infrastructure of 5G. 1) CUPS: CP/UP Separation Chen Expires June 28, 2018 [Page 4] Internet-Draft 5G Core Structure Yang Data Model December 2017 2) SBA: Service Based Architecture 3) Slicing 5G Core CP/UP functions are componentized into NFs, including NSSF, NEF, NRF, PCF, UDM, AUSF, AMF, SMF and UPF. The above components are required to be stateless and able to communicate with network based API. Furthermore, the NFs should be virtualized to be decouple to any hardware. Consequently, CP/UP function components can be flexibly deployed in native cloud environment. Figure 1 presents the overall 5G network view. +------------------------------------------------------+ | | | +--------------------------------------------------+ | | | | | | | +------+ +------+ +------+ +------+ +------+ | | +------+ | | | NSSF | | NEF | | NRF | | PCF | | UDM | | | | AF | | | +---+--+ +---+--+ +---+--+ +---+--+ +---+--+ | | +---+--+ | | | | | | | | | | | |-----+-----+---+---------+---+-----+-----+---+----+-+-----+ | | | | | | | | | +----+----+ +----+----+ +---+------+ | | | | | AUSF | + + AMF | | SMF | | | | | +---------+ / +-----+---+ +-----+----+ | | | |5G Core CP NF / | | | | | +-------------------/----------+------------+------+ | | / | | | | / | +-----+----+ | | / | | UPF +---+-+ | / | +-----+----+ | | | 5G Core NF / | | | | +---------------/----------------+------------+--------+ | / | | | +---+---+ +-----+--+ | +--------+-------+ | UE +--------+ (R)AN +---------+ | Data Network | +-------+ +--------+ +----------------+ Figure 1: 5G Network View 2.2. Management Structure ETSI defines the NFV architectural framework as Figure 2. Network management system(EMS as below) manages the network based on VNF. Each VNF has an NBI to communicate with EMS. +-----------------------------------------------------------+ Chen Expires June 28, 2018 [Page 5] Internet-Draft 5G Core Structure Yang Data Model December 2017 | OSS/BSS | +-----------------------------+-----------------------------+ | +-----------------------------+-----------------------------+ | VNF | | +-------------+ +-------------+ +---------------+ | | | EMS 1 | | EMS 2 | | EMS 3 | | | +------+------+ +------+------+ +-------+-------+ | | | | | | | +------+------+ +------+------+ +-------+-------+ | | | VNF 1 | | VNF 2 | | VNF 3 | | | +------+------+ +------+------+ +-------+-------+ | +----------+-----------------+------------------+-----------+ | | | +----------+-----------------+------------------+-----------+ | VNFI | | +-----------------------------------------------------+ | | | +-------------+ +-------------+ +-------------+ | | | | | Virtual | | Virtual | | Virtual | | | | | | Compute | | Storage | | Network | | | | | +-------------+ +-------------+ +-------------+ | | | | Virtualization Layer | | | +-------------------------+---------------------------+ | | | | | +-------------------------+---------------------------+ | | | Hardware Resources | | | | +-------------+ +-------------+ +-------------+ | | | | | Compute | | Storage | | Network | | | | | | Hardware | | Hardware | | Hardware | | | | | +-------------+ +-------------+ +-------------+ | | | +-----------------------------------------------------+ | +-----------------------------------------------------------+ Figure 2: NFV Architectural Framework In 5G core network, NFs will be grouped into VNF as Figure 3 and Figure 4. Moreover, the packaging and definition of VNF is flexible 1) AMF could be a VNF 2) AMF and SMF + SAPC could be a VNF 3) SMF + 3PP extended IP allocator could be a VNF 4) SMF + UPF could be a VNF 5) Any NFs could be grouped in one VNF 6) ... NBI NBI | | | | ,''''''''''|'|'''''''''''''''''''''|'|'''''''''`. Chen Expires June 28, 2018 [Page 6] Internet-Draft 5G Core Structure Yang Data Model December 2017 | | | | | | | ..................... ..................... | | : Virtual Network : : Virtual Network : | | : Function : : Function : | | :+-----+-----+-----+: :+-----+-----+-----+: | | :| Net | Net | Net |: :| Net | Net | Net |: | | :|Func.|Func.|Func.|: :|Func.|Func.|Func.|: | | :+-----+-----+-----+: :+-----+-----+-----+: | | : : : : | | :...................: :...................: | | | | 5G Core Network | `''''''''''''''''''''''''''''''''''''''''''''''' Figure 3: NF and VNF Relationships +--------------------------------------------------------------+ |+----------+ +---+ +----------+ +------++------++-----------+ | || UPD | |AMF| | SMF | | NSSF || NEF || NRF | | |+----------+ +---+ +----------+ +------++------++-----------+ | | | | ... | | | | VNF | +--------------------------------------------------------------+ Figure 4: 5G core NF and VNF Relationships 2.3. Model Proposal The overall structure is: module: example-5g-core-network +--rw modules-state [RFC7895] | +--rw interfaces [RFC7223] +--rw hardware +--rw system-management [RFC7317 or derived] | ... [Here, define the generic protocols for NFs] | +--rw nssf +--rw nef +--rw nrf +--rw pcf +--rw udm Chen Expires June 28, 2018 [Page 7] Internet-Draft 5G Core Structure Yang Data Model December 2017 +--rw ausf +--rw amf +--rw smf +--rw upf | +--rw virtual-network-functions +--rw virtual-network-function [name] | +--rw name +--rw enable +--rw description +--rw network-functions +--rw network-function [name] | +--rw name +--rw enable +--rw description +--rw type | +--:(upf) | +--rw (nf-root) +--:(upf-root) +--mp upf-root 3. YANG Module file "example-5g-core-network.yang" module example-5g-core-network { yang-version "1.1"; /*** NAMESPACE / PREFIX DEFINITION ***/ namespace "urn:example:5g-core-network"; prefix "core-net"; /*** LINKAGE (IMPORTS / INCLUDES) ***/ import ietf-yang-schema-mount { prefix yangmnt; reference "draft-ietf-netmod-schema-mount: YANG Schema Mount"; } /*** META INFORMATION ***/ organization "Ericsson (China) Communications Company Ltd. Ericsson Tower, No. 5 Lize East Street, Chen Expires June 28, 2018 [Page 8] Internet-Draft 5G Core Structure Yang Data Model December 2017 Chaoyang District Beijing 100102, P.R. China"; contact "Editor: Chin Chen "; description "This YANG module provide the example on 5G core network structure."; revision 2017-12-28 { description "Initial revision."; reference "RFC XXXX: A YANG Data Model for 5G Core Network Structure."; } /*** TYPE DEFINITIONS ***/ identity network-function-type { description "Base identity for derivation of network functions"; } identity nssf { base network-function-type; description "Network Slice Selection Function"; reference ""; } identity nef { base network-function-type; description "Network Exposure Function"; reference ""; } identity nrf { base network-function-type; description "NF Repository Function"; reference ""; Chen Expires June 28, 2018 [Page 9] Internet-Draft 5G Core Structure Yang Data Model December 2017 } identity pcf { base network-function-type; description "Policy Control function"; reference ""; } identity udm { base network-function-type; description "Unified Data Management"; reference ""; } identity ausf { base network-function-type; description "Authentication Server Function"; reference ""; } identity amf { base network-function-type; description "Core Access and Mobility Management Function"; reference ""; } identity smf { base network-function-type; description "Session Management Function"; reference ""; } identity upf { base network-function-type; description "User Plane Function"; reference Chen Expires June 28, 2018 [Page 10] Internet-Draft 5G Core Structure Yang Data Model December 2017 ""; } /*** SCHEMA DEFINITIONS ***/ container ietf-yang-library { description "YANG Module Library as defined in draft-ietf-netconf-yang-library"; } container interfaces { description "Interface list as defined by RFC7223/RFC7224"; } container hardware { description "Hardware / vendor-specific data relevant to the platform. This container is an anchor point for platform-specific configuration and operational state data. It may be further organized into chassis, line cards, ports, etc. It is expected that vendor or platform-specific augmentations would be used to populate this part of the device model"; } container system-management { description "System management for physical or virtual device."; } container virtual-network-functions { description "Container for list of configured virtual network functions."; list virtual-network-function { key "name"; description "Lisf for instance of virtual network function"; leaf name { type string; description "The virtual network function name."; } leaf enable { type boolean; Chen Expires June 28, 2018 [Page 11] Internet-Draft 5G Core Structure Yang Data Model December 2017 description "Enable the virtual network fucntion."; } leaf description { type string; description "Describe the virtual network fucntion."; } container network-functions { description "Container for list of configured network functions."; list network-function { key "name"; description "Lisf for instance of network function"; leaf name { type string; description "The network function name."; } leaf type { type identityref { base network-function-type; } mandatory true; description "The network function type e.g., UPF, SMF, AMF etc."; } leaf enable { type boolean; description "Enable the network fucntion."; } leaf description { type string; description "Describe the network fucntion."; } Chen Expires June 28, 2018 [Page 12] Internet-Draft 5G Core Structure Yang Data Model December 2017 choice root { description "Well known mount points."; case upf-root { description "Container for mount point."; yangmnt:mount-point "upf-root" { description "Root models that support network function UPF."; } } case amf-root { description "Container for mount point."; yangmnt:mount-point "amf-root" { description "Root models that support network function AMF."; } } case smf-root { description "Container for mount point."; yangmnt:mount-point "smf-root" { description "Root models that support network function SMF."; } } } } } } } } 4. Security Considerations The data model defined does not create any security implications. Chen Expires June 28, 2018 [Page 13] Internet-Draft 5G Core Structure Yang Data Model December 2017 5. IANA Considerations This draft does not request any IANA action. 6. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [Network Functions Virtualisation White Paper] ETSI. link: http://portal.etsi.org/NFV/NFV_White_Paper2.pdf [I-D.ietf-rtgwg-device-model] A. Lindem, Ed., L. Berger, Ed., D. Bogdanovic, C. Hopps, "Network Device YANG Logical Organization", draft-ietf-rtgwg-device-model-02 (work in progress), March 2017. [I-D.ietf-rtgwg-lne-model] Berger, L., Hopps, C., Lindem, A., and D. Bogdanovic, "YANG Logical Network Elements", draft-ietf- rtgwg-lne-model-01 (work in progress), October 2016. [I-D.ietf-rtgwg-ni-model] Berger, L., Hopps, C., Lindem, A., and D. Bogdanovic, "YANG Network Instances", draft-ietf-rtgwg-ni- model-01 (work in progress), October 2016. [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC6021] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6021, DOI 10.17487/RFC6021, October 2010, . [RFC7317] Bierman, A. and M. Bjorklund, "A YANG Data Model for System Management", RFC 7317, DOI 10.17487/RFC7317, August 2014, . Authors' Addresses Chen Expires June 28, 2018 [Page 14] Internet-Draft 5G Core Structure Yang Data Model December 2017 Chin Chen Ericsson (China) Communications Company Ltd. Ericsson Tower, No. 5 Lize East Street, Chaoyang District Beijing 100102, P.R. China Email: chin.chen@ericsson.com Adrian Pan Ericsson (China) Communications Company Ltd. Ericsson Tower, No. 5 Lize East Street, Chaoyang District Beijing 100102, P.R. China Email: adrian.pan@ericsson.com Chen Expires June 28, 2018 [Page 15]