Internet DRAFT - draft-geng-teas-enhanced-vpn-scalable-vtn-yang
draft-geng-teas-enhanced-vpn-scalable-vtn-yang
Network Working Group X. Geng
Internet-Draft Z. Hu
Intended status: Experimental Huawei
Expires: December 5, 2021 June 03, 2021
YANG Model for Scalable VTN
draft-geng-teas-enhanced-vpn-scalable-vtn-yang-01
Abstract
This document defines the Yang data model for scalable Virtual
Transport Network(VTN).
Requirements Language
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 [RFC2119].
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). Note that other groups may also distribute
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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."
This Internet-Draft will expire on December 5, 2021.
Copyright Notice
Copyright (c) 2021 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
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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
2. VTN Yang Module Requirement . . . . . . . . . . . . . . . . . 3
2.1. VTN Creation . . . . . . . . . . . . . . . . . . . . . . 3
2.2. VTN Initiation . . . . . . . . . . . . . . . . . . . . . 4
2.3. VTN Traffic Steering . . . . . . . . . . . . . . . . . . 4
3. VTN Yang Module Tree . . . . . . . . . . . . . . . . . . . . 5
4. VTN Yang Module . . . . . . . . . . . . . . . . . . . . . . . 6
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
6. Contributor . . . . . . . . . . . . . . . . . . . . . . . . . 12
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.1. Normative References . . . . . . . . . . . . . . . . . . 12
7.2. Informative References . . . . . . . . . . . . . . . . . 14
Appendix A. An Appendix . . . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
[I-D.ietf-teas-ietf-network-slice-definition] defines IETF network
slices that provide connectivity coupled with network resources
commitment between a number of endpoints over a shared network
infrastructure.
Enhanced VPN (VPN+) aims to provide enhancements to existing VPN
services to support network slicing. VPN+ is composed of a VPN
overlay and an underlying Virtual Transport Network (VTN) which has a
customized network topology and a set of dedicated or shared
resources in the underlay network. VPN+ and VTN are defined in
[I-D.ietf-teas-enhanced-vpn].
[I-D.dong-teas-enhanced-vpn-vtn-scalability] describes the
scalability considerations in the control plane and data plane to
enable VPN+ services. In control plane, decoupling the topology and
resource attributes of VTN allows that multiple VTNs share the same
topology. In data plane, a global VTN-ID in the data packet is used
to determine the set of resources reserved for the corresponding VTN.
This document defines the configuration yang model for scalable VTN
solution.
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2. VTN Yang Module Requirement
The general process of VTN configuration includes:
1. Creat VTN instance based on the network slice requirement
2. Configure the overlay network to initiate VTN in the network
3. Steer the traffic to the corresponding VTN to provide network
slice service
The corresponding requirement of VTN configuration data model during
the process is defined in this section.
2.1. VTN Creation
After collecting information about the underlying network topology
and available resources. Each VTN can have a customized topology and
a set of network resources allocated. Flexible combination is
allowed when multiple VTNs may shared the same topology, or multiple
VTNs may share the same set of network resources.
VTN is created with the following attributes:
o VTN Topology: Based on the existing work in IETF, topology
specification for VTN could be implemented by Multi-Topology
Routing (MTR) which defined in [RFC4915], [RFC5120], or Flex-algo
which is defined in [I-D.ietf-lsr-flex-algo]. Correspondingly,
the topology attribute of a VTN could be determined by MT-ID or
algorithm ID; Signaling extensions for VTN topology is defined in
[I-D.zhu-lsr-isis-sr-vtn-flexalgo] and
[I-D.ietf-lsr-isis-sr-vtn-mt] respectively.
o Network Resource: network resource is allocated for VTN based on
the requirement. For example, VTN could be bound with a layer 2
sub-interface with a subset of the link bandwidth.
o VTN Data Plane Identifier: VTN data plane identifier is uesed to
identify network resource that has been allocated for the VTN.
VTN data plane identifier depends on the encapsulation type of the
traffic, for example IPv6 defined in
[I-D.dong-6man-enhanced-vpn-vtn-id]. VTN data plane identifier is
not mandatory when there are other methods to distinguish VTN
instances.
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2.2. VTN Initiation
VTN initiation in the network also includes two aspects: resource
allocation and traffic steering through VTN specified topology.
Resource allocation is defined in this section and traffic steering
is defined in the next section.
Several technologies could be used for resource allocation in the
network device, for example: TSN defined in IEEE 802.1 introduces the
concept of time aware shaping; FlexE provides the ability to
multiplex multiple channels over one or more Ethernet links; Existing
Diffserv scheduling/shaping allow the construction of virtual sub-
interfaces. All these technologies could be used to dedicated
resource in a shared physical interface.
The configuration of these technologies play the role of VTN
initiation when the allocated resource is bound with a specified VTN
instance.
2.3. VTN Traffic Steering
Just as color in SR policy defined in
[I-D.ietf-spring-segment-routing-policy], color is defined as an
attribute of VTN to steer the traffic.
With SR policy, traffic could be steered into a SR policy by :
o SR policy with color is provisioned to the headend;
o The route with some particular color matchs the SR policy with the
corresponding color, which could satisfy the requirement of the
route
o Traffic with the route is steered into the SR policy;
Similarly, traffic could be steered into VTN by:
o VTN is configured with the attribute of color;
o The route with some particular color matchs VTN with the
correponding color, which could satisfy the requirement of the
route
o Traffic with the route is steered to the VTN
SR policy could also be bound with VTN to provide resource
reservation in the network. BGP SR Policy extensions for VTN is
defined in [I-D.dong-idr-sr-policy-vtn] and similarly, YANG model
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which is used to bound SR policy to a specified VTN is defined in
this document by:
o SR policy with color is provisioned to the headend; The preferred
candidate path is bound to VTN;
o The route with some particular color matchs the SR policy with the
corresponding color, which could satisfy the requirement of the
route
o Traffic with the route is steered into the SR policy; Packet is
encapsulated with the VTN data plane identifier.
3. VTN Yang Module Tree
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module: ietf-vtn
+--rw vtn-instance
+--rw vtn-instance* [vtn-id]
+--rw vtn-id uint32
+--rw vtn-topology
| +--rw (vtn-topolgy-type)?
| +--:(flex-algo)
| | +--rw flex-algo
| | +--rw flex-algo-id? uint32
| +--:(multi-topology)
| +--rw multi-topology-id? uint32
+--rw data-plane
| +--rw vtn-data-plane-identifier? uint32
+--rw steering-policy
+--rw vtn-color-id? uint32
augment /rt:routing/sr-policy:segment-routing/sr-policy:traffic-engineering/sr-policy:policies/sr-policy:policy/sr-policy:candidate-paths/sr-policy:candidate-path:
+--rw vtn-id-sr-policy
+--rw vtn-id? uint32
augment /if:interfaces/if:interface:
+--rw interface-configuration-for-vtn
+--rw (vtn-interface-binding-type)?
+--:(layer-2-sub-interface)
| +--rw layer-2-sub-interface
| +--rw sub-interface-id? uint32
| +--rw vtn-id? uint32
| +--rw bandwidth? uint32
+--:(queue)
+--rw queue
+--rw queue-id? uint32
+--rw vtn-id? uint32
+--rw bandwidth? uint32
augment /ni:network-instances/ni:network-instance:
+--rw vtn-traffic-steering
+--rw color-index? uint32
+--rw vtn-id? uint32
4. VTN Yang Module
<CODE BEGINS>
module ietf-vtn {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-vtn";
prefix "ietf-vtn";
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import ietf-inet-types {
prefix "inet";
}
import ietf-routing {
prefix "rt";
}
import ietf-routing-types {
prefix "rt-types";
}
import ietf-yang-types {
prefix "yang";
}
import ietf-interfaces {
prefix "if";
}
import ietf-network-instance {
prefix "ni";
}
import ietf-sr-policy {
prefix "sr-policy";
}
organization "IETF TEAS Working Group";
contact
"
WG Web: <http://tools.ietf.org/wg/teas/>
WG List:<mailto:teas@ietf.org>
Editor: Xuesong Geng
<mailto:gengxuesong@huawei.com>
Editor: Zhibo Hu
<mailto:huzhibo@huawei.com>
";
description
"This YANG module defines a data model for VTN(Virtual Transport Network)";
revision "2021-04-14" {
description
"This is the initial version of VTN yang module";
reference
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"RFC XXX: YANG Data Model for VTN";
}
grouping vtn-instances{
description
"VTN instances";
list vtn-instance {
key "vtn-id";
description
"vtn instance list";
leaf vtn-id {
type uint32;
description
"vtn-id";
}
container vtn-topology {
description
"vtn topology is nt";
choice vtn-topolgy-type{
description
"customized topology of VTN";
case flex-algo {
container flex-algo {
description
"flex-algo could be used as topology specification for VTN";
leaf flex-algo-id {
type uint32;
description
"flex-algo-id for VTN";
}
}
}
case multi-topology {
description
"MT could be used as topology specification for VTN";
leaf multi-topology-id{
type uint32;
description
"MT-id for VTN";
}
}
}
}
container data-plane {
description
"vtn data plane mechanism";
leaf vtn-data-plane-identifier {
type uint32;
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description
"VTN identifier of data plane for vtn distinguishment";
}
}
container steering-policy {
description
"Policy set that matches to a VTN";
leaf vtn-color-id {
type uint32;
description
"VTN color ID for VTN traffic steering";
}
}
}
}
grouping interface-configuration-for-vtn{
description
"interface configuration for vtn";
container interface-configuration-for-vtn {
description
"interface configuration for vtn";
choice vtn-interface-binding-type{
description
"vtn interface binding type";
case layer-2-sub-interface {
description
"vtn is bound to a layer-2 sub-interface";
container layer-2-sub-interface {
description
"sub-interface configuration";
leaf sub-interface-id {
type uint32;
description
"sub-interface id";
}
leaf vtn-id {
type uint32;
description
"vtn-id";
}
leaf bandwidth {
type uint32;
description
"bandwidth allocation for the slice";
}
}
}
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case queue {
description
"vtn is bound to a queue in the interface";
container queue {
description
"queue configuration";
leaf queue-id {
type uint32;
description
"queue id";
}
leaf vtn-id {
type uint32;
description
"queue id";
}
leaf bandwidth {
type uint32;
description
"bandwidth allocation for the slice";
}
}
}
}
}
}
grouping sr-policy-traffic-steering{
container vtn{
description
"candidata path is bound to VTN";
leaf vtn-id{
type uint32;
description
"vtn";
}
}
}
grouping vtn-traffic-steering{
container vtn-traffic-steering {
leaf color-index {
type uint32;
description
"color index";
}
leaf vtn-id {
type uint32;
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description
"vtn id";
}
}
}
container vtn-instance {
description
"vtn instance configuraiton";
uses vtn-instances;
}
grouping vtn-id-sr-policy {
description
"VTN ID for SR policy";
container vtn-id-sr-policy {
description
"VTN ID for SR policy";
leaf vtn-id {
type uint32;
description
"vtn id";
}
}
}
augment "/rt:routing/sr-policy:segment-routing/sr-policy:traffic-engineering/sr-policy:policies/sr-policy:policy/sr-policy:candidate-paths/sr-policy:candidate-path" {
description
"VTN ID for candidate path in SR path";
uses vtn-id-sr-policy;
}
augment "/if:interfaces/if:interface" {
description
"interface model extension for vtn";
uses interface-configuration-for-vtn;
}
augment /ni:network-instances/ni:network-instance{
description
"network instance model extension for vtn";
uses vtn-traffic-steering;
}
}
<CODE ENDS>
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5. IANA Considerations
This document makes no request of IANA.
Note to RFC Editor: this section may be removed on publication as an
RFC.
6. Contributor
Zhenbin Li
Huawei
Email: lizhenbin@huawei.com
Jie Dong
Huawei
Email: jie.dong@huawei.com
7. References
7.1. Normative References
[I-D.dong-6man-enhanced-vpn-vtn-id]
Dong, J., Li, Z., Xie, C., and C. Ma, "Carrying Virtual
Transport Network Identifier in IPv6 Extension Header",
draft-dong-6man-enhanced-vpn-vtn-id-03 (work in progress),
February 2021.
[I-D.dong-idr-sr-policy-vtn]
Dong, J., Hu, Z., and R. Pang, "BGP SR Policy Extensions
for Virtual Transport Network", draft-dong-idr-sr-policy-
vtn-00 (work in progress), October 2020.
[I-D.dong-teas-enhanced-vpn-vtn-scalability]
Dong, J., Li, Z., Qin, F., Yang, G., and J. N. Guichard,
"Scalability Considerations for Enhanced VPN (VPN+)",
draft-dong-teas-enhanced-vpn-vtn-scalability-02 (work in
progress), February 2021.
[I-D.ietf-lsr-flex-algo]
Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and
A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex-
algo-15 (work in progress), April 2021.
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[I-D.ietf-lsr-isis-sr-vtn-mt]
Xie, C., Ma, C., Dong, J., and Z. Li, "Using IS-IS Multi-
Topology (MT) for Segment Routing based Virtual Transport
Network", draft-ietf-lsr-isis-sr-vtn-mt-00 (work in
progress), March 2021.
[I-D.ietf-spring-segment-routing-policy]
Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and
P. Mattes, "Segment Routing Policy Architecture", draft-
ietf-spring-segment-routing-policy-11 (work in progress),
April 2021.
[I-D.ietf-teas-enhanced-vpn]
Dong, J., Bryant, S., Li, Z., Miyasaka, T., and Y. Lee, "A
Framework for Enhanced Virtual Private Network (VPN+)
Services", draft-ietf-teas-enhanced-vpn-07 (work in
progress), February 2021.
[I-D.ietf-teas-ietf-network-slice-definition]
Rokui, R., Homma, S., Makhijani, K., Contreras, L. M., and
J. Tantsura, "Definition of IETF Network Slices", draft-
ietf-teas-ietf-network-slice-definition-01 (work in
progress), February 2021.
[I-D.zhu-lsr-isis-sr-vtn-flexalgo]
Zhu, Y., Dong, J., and Z. Hu, "Using Flex-Algo for Segment
Routing based VTN", draft-zhu-lsr-isis-sr-vtn-flexalgo-02
(work in progress), February 2021.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC4915] Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P.
Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF",
RFC 4915, DOI 10.17487/RFC4915, June 2007,
<https://www.rfc-editor.org/info/rfc4915>.
[RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
Topology (MT) Routing in Intermediate System to
Intermediate Systems (IS-ISs)", RFC 5120,
DOI 10.17487/RFC5120, February 2008,
<https://www.rfc-editor.org/info/rfc5120>.
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7.2. Informative References
[InfRef] , 2004.
Appendix A. An Appendix
Authors' Addresses
Xuesong Geng
Huawei
Email: gengxuesong@huawei.com
Zhibo Hu
Huawei
Email: huzhibo@huawei.com
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