Internet DRAFT - draft-chin-nfvrg-cloud-5g-core-structure-yang
draft-chin-nfvrg-cloud-5g-core-structure-yang
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
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This Internet-Draft will expire on February 28, 2009.
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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
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"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.
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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
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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.
+-----------------------------------------------------------+
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| 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
| | | |
,''''''''''|'|'''''''''''''''''''''|'|'''''''''`.
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| | | | | |
| ..................... ..................... |
| : 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
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+--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
<CODE BEGINS> 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,
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Chaoyang District Beijing 100102, P.R. China";
contact
"Editor: Chin Chen
<mailto:chin.chen@ericsson.com>";
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
"";
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}
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
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"";
}
/*** 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;
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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.";
}
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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.";
}
}
}
}
}
}
}
}
<CODE ENDS>
4. Security Considerations
The data model defined does not create any security implications.
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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, <http://www.rfc-
editor.org/info/rfc6020>.
[RFC6021] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6021,
DOI 10.17487/RFC6021, October 2010, <http://www.rfc-
editor.org/info/rfc6021>.
[RFC7317] Bierman, A. and M. Bjorklund, "A YANG Data Model for
System Management", RFC 7317, DOI 10.17487/RFC7317, August
2014, <http://www.rfc-editor.org/info/rfc7317>.
Authors' Addresses
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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
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