Internet DRAFT - draft-hares-i2rs-service-topo-dm
draft-hares-i2rs-service-topo-dm
I2RS S. Hares
Internet-Draft L. Dunbar
Intended status: Standards Track Huawei
Expires: August 15, 2016 February 12, 2016
A Yang model for I2RS service topology
draft-hares-i2rs-service-topo-dm-06.txt
Abstract
This document defines I2RS protocol-independent service layer virtual
topology data model. This data model utilizes the concepts in the
generic I2RS topology model of virtual networks (node, links,
termination points) and cross-layer topologies. This virtual service
topology may be a composite layer created from the combination of
protocol-dependent service layers. Protocol-dependent services
layers include: L3VPN, L2VPN, EVPN, E-Tree, and others.
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
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
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 August 15, 2016.
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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Conventions used in this document . . . . . . . . . . . . 2
1.2. Base Model: the Service-Topology Component . . . . . . . 3
2. High level Yang architecture . . . . . . . . . . . . . . . . 4
2.1. Network level . . . . . . . . . . . . . . . . . . . . . . 5
2.2. Node level . . . . . . . . . . . . . . . . . . . . . . . 5
2.3. Service Link and Termination point . . . . . . . . . . . 6
3. Yang Data Model . . . . . . . . . . . . . . . . . . . . . . . 8
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
5. Security Considerations . . . . . . . . . . . . . . . . . . . 15
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.1. Normative References . . . . . . . . . . . . . . . . . . 15
6.2. Informative References . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
Service topology in [I-D.ietf-i2rs-yang-network-topo] includes the a
virtual topology for a service layer above the L1, L2, and L3 layers.
This virtual topology has the generic topology elements of node,
link, and terminating point. The virtual service topology is a
network-wide topology stored on one routing system which an I2RS
agent is connected to.
The virtual service topology is a composite summary of the services
available services gathered from the lower layer indications of
L3VPN, L2VPN, and EVPN services, E-TREE services, Seamless MPLS
topologies within an As and others. This is a "bottoms up" yang
module providing composite protocol independent service topology
based on these protocol services.
This "bottoms-up" yang model does provide a mechanism to link this
bottoms up model to a top-down service model. One example of a top-
down service model for L3 VPNs is the L3 Service yang data model
[I-D.ietf-l3sm-l3vpn-service-model]. Although the two models are
linked, the top-down service model cannot be derived from the lower
layers.
1.1. 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 [RFC2119].
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1.2. Base Model: the Service-Topology Component
The following diagram contains an informal graphical depiction of the
main elements of the information model:
+----------------+
| network |
| topology |<...
+----------------+ :
* * : :
| | :...:
| |
+--------+ +--------+
...>| node |<.......|link |<...
: +--------+<.......+--------+ :
: : * : : * : :
:..... | : : | :...:
| : : |
.....>+--------+<........: : |
: | TP |<..........: |
: ...>+--------+ |
: : |
: : .....................+---------+
.........................|Direction|
+---------+
Figure 1
The link between the upper layer and the lower layer occurs by
linking the bottoms up service network topologies to Top-down service
topologies at certain service nodes to support transport of service
across a virtual service link.
An example of the top-down service topology link to the bottoms up
composite service topology may help. Suppose a bottoms up topology
contains a composite of 3 L3VPN network topologies, 2 L2VPN network
topologies, and 2 EVPN network topologies. Each of these physical
networks can support virtual networks on top of the physical network.
The service network base bottoms up is formed topology map with all
of these topologies.
Suppose an L3SM has three VPN services topologies which support three
services over 9 virtual topologies transiting the 2 of the L3VPN
networks.
o VPN-svc 1: supporting hub-spoke flow for Customer 1 with 2 Cloud
identifiers (2 topologies) with connecting the customers access at
3 sites
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o VPN-svc 2: supporting hub-spoke flow disjoint for Customer 2 with
2 Cloud identifiers (2 topologies) at 3 sites,
o VPN-svc 3: supporting any-to-any flow for Customer 3 with 1 Cloud
Identifier (5 topologies) at 3 sites.
Let us examine how VPN-svc 1 links to the composite cloud. Let us
assume for simplicity of the example that the nodes providing the
L3VPN provider equipment (PE) and the customer equipment (CE) at all
sites are all unique. The diagram of how the top-down service
topology meets the bottom up service topology is shown in figure
L3SM topologies
Service-topology [VPN-ID:1]
/ \
cloud 1 topology 1 cloud 2 topology-1
/ | \ / | \
Site-1A site-1B site1-C site-1A Site-1B Site-1C
| | | | | |
====|==========|=======|=======|=========|=====|====
+-------+ | \ / / |
Bottoms-up | | \ / / |
service | | /\ / |
topology | | / \ | |
L3VPN-Service-topology 1 L3VPN-Service Topology-2
| | | | | |
node1 node2 node3 node4 node5 node6
PE PE PE PE PE PE
| | | | | |
CE CE CE CE CE CE
Figure 2
These two layers of service topologies are by two different composite
models composite models and different supporiting models as follows:
o Top-Down Provider Services with supporting L3SM model,
o Bottom-Up I2RS Composite Services with supporting model from
L3VPN, L2VPN, EVPN (only L3VPN used). The links between
topologies occur at specific nodes.
2. High level Yang architecture
This section describes the Yang High level architecture.
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2.1. Network level
The service topology network level defines the following high-level
yang architeture:
module: i2rs-service-topologies
augment /nw:network/nw:network-types:
+--rw service-topologies-types
augment /nw:network:
+--rw service-topology-attributes
+--rw name? string
+--rw description? string
+--rw composite-flag* identity-ref
+--rw tdsvc-supports-attributes*
[tdsvc-attr-name]
+--rw tdsvc-attr-name string
+--rw tdsvc-supports-attribute* identityref
Note: Composite flags are bottoms-up flags
Figure 3
The service topology attributes for a network include the following
name - name of the service topology,
description - description of service topology
composite-flags - bit mask with flags of service layer topologies
network topology node available to create service topology from.
These topologies include: L3VPN, L2VPN, and EVPN services, E-TREE
services, Seamless MPLS topologies within an AS and others.
tdsvc-supports-attributes - composite topology supports top-down
services topology attributes
tdsvc-supports-attr-name - name of top-down service attribute
tdsvc-supports-attribute - identity ref of service attribute
(e.g. L3SM service for any-to-any)
2.2. Node level
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module: i2rs-service-topologies
....
augment /nw:network/nw:node
+--rw node-service-attributes
+--rw c-svc-node-name? inet:domain-name
+--rw c-svc-node-flag* identityref;
+--rw tdsvc-node-supports-attributes*
[tdsvc-node-attr-name]
+--rw tdsvc-node-attr-name string;
+--rw tdsvc-node-supports-attribute identityref
// Top down attributes supported
The additional fields in the service attributes are the following:
c-svc-node-name - name of network node,
c-svc-node-flag - composite service topology node flag. The
service node can be a member of one of the existing topology type
(L3VPN, L2VPN, EVPN, E-TREE, Seamless MPLS, MPLS-TE, MPLS node, or
I2RS created).
tdsvc-node-supports-attributes - node supports top-down services
topology attributes
tdsvc-supports-node-attr-name - name of top-down service
attribute
tdsvc-supports-node-attribute - identity ref of service
attribute (e.g. L3SM service for any-to-any)
2.3. Service Link and Termination point
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augment /nw:network/nt:link:
+--rw service-link-attributes
+--rw c-svc-link-name? string
+--rw c-svc-link-type identityref
+--rw c-svc-link-metric? uint32
+--rw tdsvc-link-supports-attr* [name]
+--rw tdsvc-link-attr-name string
+--rw tdsvc-link-attribute identityref
augment /nw:network/nw:node/nt:termination-point:
+--rw service-termination-point-attributes
+--rw svc-tp-name string
+--rw svc-tp-type identityref
+--rw tdsvc-tp-support-attributes
+--rw tdsvc-tp-attr-name
+--rw tdsvc-tp-support-attribute
The augmentation to the service topology is the service link
attributes which include:
c-svc-link-name - name of the link,
c-svc-link-type - the service link type supported by this logical
link.
metric - the metric of the service type. This metric allows the
composite link to store a svc level metric. 0 = no servic metric.
1-n values (1 best, n worse).
svc-attributes - the composite attributes of link
tdsvc-td-support-attributes - link support of Top-down attributes
tdsvc-supports-node-attr-name - name of top-down service
attribute
tdsvc-supports-node-attribute - identity ref of service
attribute (e.g. L3SM service for any-to-any)
The augmentation to the termination point include the following
svc-tp-name - name of termination point,
tp-type - type of link (L3VPN, L2VPN, combined)
tdsvc-tp-support-attributes - list of top-level domain-name
attributes this links supports.
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3. Yang Data Model
<CODE BEGINS> file "ietf-i2rs-service-topology@2016-02-q0.yang"
module ietf-i2rs-service-topology{
namespace "urn:ietf:params:xml:ns:yang:ietf-i2rs-service-topology";
prefix i2rs-st;
import ietf-inet-types {
prefix inet;
}
import ietf-network {
prefix nw;
}
import ietf-network-topology {
prefix "nt";
}
organization "IETF";
contact
"email: shares@ndzh.com;
email: linda.dunbar@huawei.com;
";
description
"This module defines a model for the service topology.
This service model imports
- ietf-network and ietf-network-topology from
draft-ietf-i2rs-yang-network-topo-02.txt,
- ietf-routing from draft-ietf-netmod-routing-cfg,
- ietf-l3vpn-svc from
draft-ietf-l3sm-l3vpn-service-model.
(not defined yet )
";
revision 2016-02-12 {
description
"Version 1 - initial version;
Version 2 - yang format fixed
Version 3 - errro in xml file
version 4 - remove next-hops attribute.
version 5- links to top-level attributes.
version 6 - Remove extra parameters.";
reference "draft-hares-i2rs-service-topo-dm-05.txt";
}
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identity svc-topo-flag-identity {
description "Base type for svc flags";
}
identity l3vpn-svc-topo {
base svc-topo-flag-identity;
description "L3VPN service type";
}
identity l2vpn-svc-topo {
base svc-topo-flag-identity;
description "L2VPN service type";
}
identity EVPN-svc-topo {
base svc-topo-flag-identity;
description "EVPN service type";
}
identity Seamless-MPLS-svc-topo {
base svc-topo-flag-identity;
description "Seamless MPLS service type";
}
identity Etree-svc-topo {
base svc-topo-flag-identity;
description "Seamless MPLS service type";
}
identity I2rs-svc-topo {
base svc-topo-flag-identity;
description "I2RS create service topo";
}
identity svc-tp-type {
description "Base type for service
termination-point type flags";
}
identity svc-tp-type-service {
base svc-tp-type;
description "service type";
}
identity svc-tp-type-ip {
base svc-tp-type;
description "service IP";
}
identity svc-tp-type-unnum {
base svc-tp-type;
description "service unnumbered link";
}
identity svc-link-type {
description "Base type for composite
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service link attribute flags";
}
identity svc-link-ip-te {
base svc-link-type;
description "service link
that support IP traffic engineering";
}
identity svc-link-ip-multicast {
base svc-link-type;
description "service link that
supports IP multicast.";
}
identity tdsvc-support-identity {
description "Base type for svc flags";
}
identity td-L3sm-hub-spoke {
base tdsvc-support-identity;
description "Supports L3SM hub-spoke";
}
identity td-L3sm-hub-spoke-disjoint {
base tdsvc-support-identity;
description "Supports L3SM hub-spoke disjoint";
}
identity td-L3sm-any-any {
base tdsvc-support-identity;
description "Supports L3SM any-any";
}
grouping svc-combo-network-type {
description "Identify the topology type to be
composite service topology.";
container svc-combo-network {
presence "indicates Service layer Network";
description
"The presence of the container node indicates
Service layer which combines networks
L3VPN, L2VPN, and others";
}
}
grouping service-topology-attributes {
leaf name {
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type string;
description "name of service
topology";
}
leaf description {
type string;
description "description
of service attribute";
}
leaf composite-flag {
type identityref {
base svc-topo-flag-identity;
}
description "other topologies
this topology is configured to
be a composite of
(L3VPN, L2VPN, I2RS only)";
}
list tdsvc-supports-attributes {
key tdsvc-attr-name;
leaf tdsvc-attr-name {
type string;
description "top-down
service support attribute name";
}
leaf tdsvc-supports-attribute {
type identityref {
base tdsvc-support-identity;
}
description "top-down service
attribute this topology supports.";
}
description "supporting top-down
service attributes. ";
}
description "Group of attributes for
service topology";
}
grouping node-svc-attribute {
leaf c-svc-node-name{
type inet:domain-name;
description "Domain name for node";
}
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leaf c-svc-flag {
type identityref {
base svc-topo-flag-identity;
}
description "virtual network
node can be composite of the
topologies list
(L3VPN, L2VPN, I2RS only)";
}
list tdsvc-node-supports-attributes {
key tdsvc-node-attr-name;
leaf tdsvc-node-attr-name {
type string;
description "name of top-down
service attribute ";
}
leaf tdsvc-node-supports-attribute {
type identityref {
base tdsvc-support-identity;
}
description "top-down service
attribute this topology supports.";
}
description "list of top-down service
attributes this node supports";
}
description
"grouping of composite flag";
}
grouping service-link-attributes {
leaf c-svc-link-name {
type string;
description "name of
service link";
}
leaf c-svc-link-type {
type identityref {
base svc-link-type;
}
description "other topologies
this link is current a
composite of
(L3VPN, L2VPN, I2RS only)";
}
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leaf c-svc-link-metric {
type uint32;
description "link metric
for servicest to
allow TE loading at composite
service level";
}
list tdsvc-link-supports-attributes {
key tdsvc-link-attr-name;
leaf tdsvc-link-attr-name {
type string;
description "top-down
service support attribute name";
}
leaf c-svc-link-td-support-attribute {
type identityref {
base tdsvc-support-identity;
}
description "top-down service
attribute this link supports.";
}
description "list of service level
link attributes";
}
description "grouping of
service link attribute";
}
grouping service-termination-point-attributes {
leaf svc-tp-name {
type string;
description "name of service
termination point";
}
leaf svc-tp-type {
type identityref {
base svc-topo-flag-identity;
}
description "other topologies
this link termination point is
part of (L3VPN, L2VPN,
or I2RS only)";
}
list tdsvc-tp-support-attributes {
key tdsvc-tp-attr-name;
leaf tdsvc-tp-attr-name {
type string;
description "top-down
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service support attribute name";
}
leaf tdsvc-tp-support-attribute {
type identityref {
base tdsvc-support-identity;
}
description "top-down service
attribute this link supports.";
}
description "list of service level
link attributes";
}
description "grouping of
service link attribute";
}
augment "/nw:networks/nw:network/nw:network-types" {
uses svc-combo-network-type;
description
"augment the network-tpyes with
the service-topology-types grouping";
}
augment "/nw:networks/nw:network" {
when "nw:network-types/svc-combo-network" {
description
"Augmentation parameters apply only for
service network with bottoms up topology";
}
description
"Augment with combo service
topology attributes";
uses service-topology-attributes;
}
augment "/nw:networks/nw:network/nw:node"{
when "nw:network-types/svc-combo-network" {
description
"Augmentation parameters apply only for
service network with bottoms up topology";
}
uses node-svc-attribute;
description
"augment the node with the node-svc-attribute";
}
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augment "/nw:networks/nw:network/nt:link" {
when "nw:network-types/svc-combo-network" {
description
"Augmentation parameters apply only for
service network with bottoms up topology";
}
uses service-link-attributes;
description
"augment the link with
service-link-attributes";
}
augment "/nw:networks/nw:network/nw:node/nt:termination-point"{
when "nw:network-types/svc-combo-network" {
description
"Augmentation parameters apply only for
service network with bottoms up topology";
}
uses service-termination-point-attributes;
description
"augment the termination-point with
service-termination-point-attributes";
}
} // module i2rs-service-topology
} // module i2rs-service-topology
<CODE ENDS>
4. IANA Considerations
TBD
5. Security Considerations
TBD
6. References
6.1. Normative References
[I-D.ietf-i2rs-yang-network-topo]
Clemm, A., Medved, J., Varga, R., Tkacik, T., Bahadur, N.,
and H. Ananthakrishnan, "A Data Model for Network
Topologies", draft-ietf-i2rs-yang-network-topo-02 (work in
progress), December 2015.
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[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
6.2. Informative References
[I-D.ietf-i2rs-yang-l3-topology]
Clemm, A., Medved, J., Varga, R., Tkacik, T., Liu, X.,
Bryskin, I., Guo, A., Ananthakrishnan, H., Bahadur, N.,
and V. Beeram, "A YANG Data Model for Layer 3 Topologies",
draft-ietf-i2rs-yang-l3-topology-01 (work in progress),
December 2015.
[I-D.ietf-l3sm-l3vpn-service-model]
Litkowski, S., Shakir, R., Tomotaki, L., and K. D'Souza,
"YANG Data Model for L3VPN service delivery", draft-ietf-
l3sm-l3vpn-service-model-02 (work in progress), December
2015.
Authors' Addresses
Susan Hares
Huawei
7453 Hickory Hill
Saline, MI 48176
USA
Email: shares@ndzh.com
Linda Dunbar
Huawei
USA
Email: linda.dunbar@huawei.com
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