| Network Working Group | D. Shytyi |
| Internet-Draft | L. Beylier |
| Intended status: Informational | SFR |
| Expires: March 29, 2020 | L. IANNONE |
| Telecom ParisTech | |
| September 26, 2019 |
A YANG Module for uCPE management.
draft-shytyi-opsawg-vysm-01
This document provides a YANG data model for uCPE management (VYSM) and definition of the uCPE equipment. The YANG Service Model serves as a base framework for managing an universal Customer-Premises Equipment (uCPE) subsystem. The model can be used by a Network Service Orchestrator.
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Network Function Virtualization is a technology that allows to virtualize the network services running on dedicaded hardware. This technology became a base for universal Customer-Premises Equipment (uCPE). This document defines the uCPE as harware with x86 capabilities that has a hypervisor. In other words, uCPE is a host that may run multiple Virtual Machines with guest OSs, where each Guest OS may represent a Physical Network Function. This document presents the YANG Service Model (VYSM) to manage from an Orchestrator the infrastructure inside the uCPE.
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 RFC 2119.
Link - is an entity that enables link layer communication of nodes.
Port - node connector to the link.
NE - Network Element.
NSYM - Network Service Yang Module.
VYSM - VNF YANG Service Model.
Firstly, this document defines the platform that is controlled with VYSM - universal CPE (uCPE). The uCPE as harware with x86 capabilities that is generally running Linux distibution with additinal virtualisation layer. Virtualization layer provides virtual compute, virtual storage and virtual network resources. Each VNF runnning in the uCPE requires the amount of virtual resources (for example: 4 vCPUs, 4GB RAM, 40GB storege, 4 vPorts). VNFs MAY be interconnected between each other and physical ports via Virtual Networks. Topology construction and VM lifecycle management is allowed via high level interface (Configuration can be done in the same transaction). The figure below presents the uCPE architecture.
----------------------------------------|--------------
VNF1 VNF2 VNF3 |
----------------------------------------|
Virtual Virtual Virtual | uCPE software
Compute Storage Networks|
----------------------------------------|---------------
PHY x86 RAM+PHY PHYsical| uCPE Hardware
processor storage ports |
The next elements can be managed in the uCPE:
uCPE supports a Virtual Network Funcitons of different type:
vSW(WAN1)--vRouter--+ +--vLoadBalance vFirewall--vSW(LAN) vSW(WAN2)--vRouter--+ | | +-vSW(Service1)+
vSW(WAN1)--vRouter(ISP1)--+ +--SD-WAN vFirewall--vSW(LAN) vSW(WAN2)--vRouter(ISP2)--+ | | +-vSW(Service1)+
The VNF in the uCPE could be a vRouter or vFirewall or an SD-WAN that is not a default part of virtual network resources of the uCPE. Multiple VNFs MAY be instantiated in the uCPE. With support of links and swithes, VNFs MAY participate a service chains. Example of service chains (Note that virtual switch "vs(WAN)" connected to LAN ports and vSW(WAN) is connected to WAN ports):
Secondly, this document defines and classifies the VYSM as Network Service YANG Module(NSYM) layer component RFC 8199. Thus it inherits the characteristics of the NSYM Layer. VYSM is a modeled representation of the specific service requirements. It provides abstraction of services configuration and operations that MAY be implemented in Network Elemets (NEs). Thus VYSM does not describe all configuration to be performed on the devices, but provides the configuration that is required for the "Network Service to Network Element(s)" decomposition process RFC 8199. Example of the decomposition is presented in the figure below.
The Network Service YANG module exposes the configuration commands via the Northbound interfaces of the orchestrator. Therefore the set of the commands modeled in the VYSM can be inputed via Notrhbound interfaces(for example CLI). In the example the command "vm VNF1" is passed via Northbound interface to the orchestrator. It defines the virtual machine name. Further the same configuration MAY be transormed to the one or multiple Network Element payloads (for example xml for NETCONF) that carry an equivalent of commands such as "nf nf-name VNF1"
+-+-+-+-+-+-+-+-+-+
| |
| config t |
| vm VNF1 |
+-+-+-+-+-+-+-+-+-+
#
#
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: :
: +-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+ :
: | Network Service YANG Module | :
: +-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+ :
: # :
: ############################## orchestrator :
: # # # :
: '---------' '------------' '-----------' :
: 'Module1 ' ' Module 2 ' ' Module3 ' <= Network Element :
: '---------' '------------' '-----------' YANG Modules :
: # # # :
: # # ####################### :
: #### ############## # :
: # # # :
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# # #
Network # element 1 Network # element 2 Network # element3
++-+-+-+-+-+-+-+-+-+-+ -+-+-+-++-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+
| domains domain VNF1| |tenants tenant name VNF1| |nf nf-name VNF1|
++-+-+-+-+-+-+-+-+-+-+ -+-+-+-++-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+
This section provides an overview of the Service YANG Model (VSYM) that MAY be made with "pyang" utility. The figure below presents the tree diagram of VYSM.
module: ietf-ucpe
+--rw ucpe* [name]
+--rw name string
+--rw links* [link]
| +--rw link string
+--rw phyInterfaces* [interface]
| +--rw interface string
| +--rw ports* [port]
| +--rw port string
| +--rw link? -> ../../../links/link
+--rw switches* [switch]
| +--rw switch string
| +--rw ports* [port]
| +--rw port string
| +--rw name? string
| +--rw link? -> ../../../links/link
+--rw vms* [vm]
+--rw vm string
+--rw ports* [port]
| +--rw port string
| +--rw name? string
| +--rw link? -> ../../../links/link
+--rw ram? uint64
+--rw cpu? uint64
+--rw storages* [id]
| +--rw id string
| +--rw location? string
+--rw day0-config
+--rw location? string
+--rw day0-var-path? string
+--rw variable* [name]
+--rw name string
+--rw value? string
This section presents the specification of the VYSM.
<CODE BEGINS> file "ietf-ucpe@2019-09-16.yang"
module ietf-ucpe {
namespace "urn:ietf:params:xml:ns:yang:ietf-ucpe";
prefix ietf-ucpe;
organization
"SFR";
contact
"Dmytro Shytyi
EMail:ietf.dmytro@shytyi.net";
description
"This YANG Service Model for uCPE management.";
revision 2018-07-01 {
description
"Initial revision.";
reference
"draft-shytyi-netmod-vysm-01";
}
revision 2019-09-16{
description
"Added 0day config for VNFs.
Yang model modified according
to the received comments.";
reference
"draft-shytyi-opsawg-vysm-00";
}
list ucpe{
key name;
leaf name {
type string;
description "ID of uCPE where
a service is instantiated";
}
list links{
key link;
leaf link{
type string;
description "Name of the virtual link from the pool
of the links";
}
description "Pool of the virtual links that connect VMs and
Interfaces";
}
list phyInterfaces{
key interface;
leaf interface{
type string;
description "Name of physical interface";
}
list ports{
key port;
leaf port{
type string;
description "Name of the connector";
}
leaf link{
type leafref{
path "../../../links/link";
}
description "Link that is connected to
the port via connector";
}
description "Set of the connectors the
physical interface has";
}
description "Set of physical interfaces";
}
list switches{
key switch;
leaf switch{
type string;
description "Name of the forwarding domain";
}
list ports{
key port;
leaf port{
type string;
description "Name of the connector";
}
leaf name{
type string;
description "Name of the
subconnector";
}
leaf link{
type leafref{
path "../../../links/link";
}
description "Link that is connected to the
switch via port";
}
description "Set of the connectors the
forwarding domain has";
}
description "Set of the forwarding domains";
}
list vms{
key vm;
leaf vm{
type string;
description "ID of the Virtual Machine";
}
list ports{
key port;
leaf port{
type string;
description "Name of the connector";
}
leaf name{
type string;
description "Name of
the subconnector";
}
leaf link{
type leafref{
path "../../../links/link";
}
description "Link that connects the
VM with a switch or Interface
via connector";
}
description "Set of Virtual Machine connectors";
}
leaf ram{
type uint64;
description "Size of RAM to allocate for
the Guest OS";
}
leaf cpu{
type uint64;
description "Number of vCPUs to
allocate for the Guest OS";
}
list storages{
key id;
leaf id{
type string;
description "Number of
vDisk attached to the VM";
}
leaf location{
type string;
description "External location where
the image (ex.qcow2) is saved.";
}
description "Virtual storge/vDisk
attached to the Virtual Machine";
}
container day0-config{
leaf location{
type string;
description "0day configuration location";
}
leaf day0-var-path{
type string;
description "path of the file
that contains the 0day variables";
}
list variable{
key name;
leaf name{
type string;
description "variable name";
}
leaf value{
type string;
description "variable value";
}
description "list of variables";
}
description "0day configuration:init config";
}
description "Set of the Virtual Machines configured
on the universal Customer-Premises Equipment";
}
description "This is an uCPE management service";
}
}
<CODE ENDS>
The XML example below presents the configuration of the next service in the uCPE, where: vSW(LAN), vSW(WAN), vSW(Service) - virtual switches; l1,l2,l3,l4 - virtual links; VMs represent PNFs (Physical Network Fuctions) that could be bootstrapped with 0day config/license.
+--------+ +-------------+ +------------+
|vSW(LAN)|--l2--|VNF-vFirewall|--l3--| |
+--------+ +-------------+ | |
+--------+ +-------------+ |vSW(Service)|
|vSW(WAN)|--l1--| VNF_vCPE |--l4--| |
+--------+ +-------------+ +------------+
<ucpe xmlns="urn:ietf:params:xml:ns:yang:ietf-ucpe">
<name>ucpe1</name>
<links>
<link>l1</link>
</links>
<links>
<link>l2</link>
</links>
<links>
<link>l3</link>
</links>
<links>
<link>l4</link>
</links>
<switches>
<switch>lan</switch>
<ports>
<port>10</port>
<name>l2p10</name>
<link>l2</link>
</ports>
</switches>
<switches>
<switch>service</switch>
<ports>
<port>10</port>
<name>l3p10</name>
<link>l3</link>
</ports>
<ports>
<port>11</port>
<name>l4p10</name>
<link>l4</link>
</ports>
</switches>
<switches>
<switch>wan</switch>
<ports>
<port>10</port>
<link>l1</link>
</ports>
</switches>
<vms>
<vm>VNF-vCPE</vm>
<ports>
<port>1</port>
<name>l1p1</name>
<link>l1</link>
</ports>
<ports>
<port>2</port>
<name>l4p2</name>
<link>l4</link>
</ports>
<ram>2048</ram>
<cpu>2</cpu>
<storages>
<id>1</id>
<location>http://192.168.2.1/vCPE-x86.qcow2</location>
</storages>
<day0-config>
<location>https://192.168.2.1/vCPE-day0.iso</location>
<day0-var-path>/config.rom</day0-var-path>
<variable>
<name>hostname</name>
<value>IETF-vCPE</value>
</variable>
<variable>
<name>ipaddress</name>
<value>192.168.1.2 255.255.255.0</value>
</variable>
</day0-config>
</vms>
<vms>
<vm>VNF-vFirewall</vm>
<ports>
<port>1</port>
<name>l3p1</name>
<link>l3</link>
</ports>
<ports>
<port>2</port>
<name>l2p2</name>
<link>l2</link>
</ports>
<ram>2048</ram>
<cpu>2</cpu>
<storages>
<id>1</id>
<location>http://192.168.2.1/vFirewall-x86.qcow2</location>
</storages>
<day0-config>
<location>https://192.168.2.1/vFirewall-day0.iso</location>
<day0-var-path>/config.rom</day0-var-path>
<variable>
<name>hostname</name>
<value>vFirewall</value>
</variable>
<variable>
<name>ipaddress</name>
<value>192.168.1.3 255.255.255.0</value>
</variable>
</day0-config>
</vms>
</ucpe>
At this time, no security considerations are addressed by this memo.
No request to IANA at this time.
The authors would like to thank:
for their valuable comments.
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
| [RFC8199] | Bogdanovic, D., Claise, B. and C. Moberg, "YANG Module Classification", RFC 8199, DOI 10.17487/RFC8199, July 2017. |