OPSAWG Working Group B. Wu, Ed.
Internet-Draft Q. Wu, Ed.
Intended status: Standards Track Huawei
Expires: January 7, 2022 M. Boucadair, Ed.
Orange
O. Gonzalez de Dios
Telefonica
B. Wen
Comcast
C. Liu
China Unicom
H. Xu
China Telecom
July 6, 2021
A YANG Model for Network and VPN Service Performance Monitoring
draft-ietf-opsawg-yang-vpn-service-pm-01
Abstract
The data model defined in RFC 8345 introduces vertical layering
relationships between networks that can be augmented to cover network
and service topologies. This document defines a YANG module for both
network performance monitoring (PM) and VPN service performance
monitoring that can be used to monitor and manage network performance
on the topology at higher layer or the service topology between VPN
sites.
The YANG model defined in this document is designed as an
augmentation to the network topology YANG model defined in RFC 8345
and draws on relevant YANG types defined in RFC 6991, RFC 8345, and
RFC 8532.
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 https://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."
Wu, et al. Expires January 7, 2022 [Page 1]
Internet-Draft Network and VPN Service PM YANG July 2021
This Internet-Draft will expire on January 7, 2022.
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
(https://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
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Network and VPN Service Performance Monitoring Model Usage . 3
3.1. Collecting Data via Pub/Sub Mechanism . . . . . . . . . . 5
3.2. Collecting Data via Retrieval Methods . . . . . . . . . . 5
4. Description of The Data Model . . . . . . . . . . . . . . . . 5
4.1. Layering Relationship between Multiple Layers of Topology 5
4.2. Network Level . . . . . . . . . . . . . . . . . . . . . . 7
4.3. Node Level . . . . . . . . . . . . . . . . . . . . . . . 7
4.4. Link and Termination Point Level . . . . . . . . . . . . 8
5. Network and VPN Service Performance Monitoring YANG Module . 11
6. Security Considerations . . . . . . . . . . . . . . . . . . . 23
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 24
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 24
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.1. Normative References . . . . . . . . . . . . . . . . . . 24
10.2. Informative References . . . . . . . . . . . . . . . . . 26
Appendix A. Illustrating Examples . . . . . . . . . . . . . . . 27
A.1. Example of Pub/Sub Retrieval . . . . . . . . . . . . . . 27
A.2. Example of RPC-based Retrieval . . . . . . . . . . . . . 29
A.3. Example of Percentile Monitoring . . . . . . . . . . . . 30
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31
1. Introduction
[RFC8969] describes a framework for automating service and network
management with YANG models, proposing the performance measurement
telemetry model to be tied with the service, such as Layer 3 VPN and
Wu, et al. Expires January 7, 2022 [Page 2]
Internet-Draft Network and VPN Service PM YANG July 2021
Layer 2 VPN, or network models to monitor the overall network
performance or Service Level Agreements (SLA).
This document defines a YANG module [RFC7950] for both network
performance monitoring and VPN service performance monitoring. This
module can be used to monitor and manage network performance on the
topology level or the service topology between VPN sites, in
particular.
This document does not introduce new metrics for network performance
or mechanisms for measuring network performance, but uses the
existing mechanisms and statistics to show the performance monitoring
statistics at the network and service layers. The YANG module
defined in this document is designed as an augmentation to the
network topology YANG model defined in [RFC8345].
This document uses the common VPN YANG module defined in
[I-D.ietf-opsawg-vpn-common].
Appendix A provides a set of examples to illustrate the use of the
module.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119][RFC8174] when, and only when, they appear in all
capitals, as shown here.
Tree diagrams used in this document follow the notation defined in
[RFC8340].
3. Network and VPN Service Performance Monitoring Model Usage
Models are key for automating network management operations.
According to [RFC8969], together with service and network models,
performance measurement telemetry models are needed to monitor
network performance to meet specific service requirements (typically
captured in an SLA). The YANG module defined in this document is
designed to derive VPN or network level performance data based on
lower-level data collected via monitoring counters of the involved
devices.
Wu, et al. Expires January 7, 2022 [Page 3]
Internet-Draft Network and VPN Service PM YANG July 2021
+---------------+
| Customer |
+-------+-------+
|
Customer Service Models |
|
+-------+---------+
| Service |
| Orchestration |
+------+-+--------+
| |
Network Service Models | | Network and VPN Service PM Models
| |
+------+-+--------+
| Network |
| Controller |
+-------+---------+
|
+-----------------------+------------------------+
Network
Figure 1: Reference Architecture
As shown in Figure 1, in the context of layering model architecture
described in [RFC8309], the network and VPN service performance
monitoring (PM) model can be used to expose some performance
information to the above layer. Such an information can be used by
an orchestrator to subscribe to performance data. The network
controller will then notify the orchestrator about corresponding
parameter changes.
Before using the network and VPN service PM model, the mapping
between the VPN service topology and the underlying physical network
should be setup. Also, the performance monitoring data per link in
the underlying network can be collected using network performance
measurement method such as MPLS Loss and Delay Measurement [RFC6374].
The performance monitoring information reflecting the quality of the
network or VPN service (e.g., end to end network performance data
between source node and destination node in the network or between
VPN sites) can be computed and aggregated, for example, the
information from Traffic Engineering Database (TED), defined in
[RFC7471], [RFC8570], or [RFC8571] or LMAP [RFC8194].
The measurement and report intervals that are associated with these
performance data usually depend on the configuration parameters.
Wu, et al. Expires January 7, 2022 [Page 4]
Internet-Draft Network and VPN Service PM YANG July 2021
3.1. Collecting Data via Pub/Sub Mechanism
Some applications such as service-assurance applications, which must
maintain a continuous view of operational data and state, can use the
subscription model [RFC8641] to subscribe to the specific network
performance data or VPN service performance data they are interested
in, at the data source.
The data source can, then, use the network and VPN service assurance
model defined in this document and the YANG Push model [RFC8641] to
distribute specific telemetry data to target recipients.
3.2. Collecting Data via Retrieval Methods
To obtain a snapshot of a large amount of performance data from a
network element (including network controllers), service-assurance
applications may use methods such as retrieving performance data or
RPC commands defined as part of YANG models.
4. Description of The Data Model
This document defines the YANG module, "ietf-network-vpn-pm", which
is an augmentation to the "ietf-network" and "ietf-network-topology".
The performance monitoring data augments the service topology as
shown in Figure 2.
+----------------------+ +-----------------------+
|ietf-network | |Network and VPN Service|
|ietf-network-topology |<---------|Performance Monitoring |
+----------------------+ augments | Model |
+-----------------------+
Figure 2: Module Augmentation
4.1. Layering Relationship between Multiple Layers of Topology
[RFC8345] defines a YANG data model for network/service topologies
and inventories. The service topology described in [RFC8345]
includes the virtual topology for a service layer above Layer 1 (L1),
Layer 2 (L2), and Layer 3 (L3). This service topology has the
generic topology elements of node, link, and terminating point. One
typical example of a service topology is described in Figure 3 of
[RFC8345]: two VPN service topologies instantiated over a common L3
topology. Each VPN service topology is mapped onto a subset of nodes
from the common L3 topology.
Wu, et al. Expires January 7, 2022 [Page 5]
Internet-Draft Network and VPN Service PM YANG July 2021
Figure 3 illustrates an example of a topology that maps between the
VPN service topology and an underlying network:
VPN 1 VPN 2
+-----------------------+ +---------------------+
/S1C-[VN3]... / /S2A S2B /
/ / \ ::::: / / -[VN1]______[VN3]- /
/ / \ : / / : : /
/ / \ S1A :: : : : : : : /
/S1B-[VN2]____[VN1]-- / / : : : /
+--------:-------:------+ +---:----:----------:-+
: : :: : : : :
: : : : :
Site-1A : +-------:--: ----- -------- : -------:-----+ Site-1C
[CE1]___: /__ ___ [N1]__________________ [N2]__ :___ /__[CE3]
:/ / / \ _____/ / : /
[CE5]___ : ___ / / \ _____/ / :: /
Site-2A /: / \ / / : /
/ : [N5] / : /
/ : / __/ \__ / : /
/ : / ___/ \__ / : /
Site-1B / : / ___/ \ / : / Site-2B
[CE2]-/------- [N4]_________________ [N3]:::-----/----[CE4]
+------------------------------------------+
Legend: N:node VN:VPN-Node
Figure 3: Example of Topology Mapping Between VPN Service Topology
and Underlying Network
As shown in Figure 3, two VPN services topologies are both built on
top of one common underlying physical network:
VPN 1: This service topology supports hub-spoke communications for
'customer 1' connecting the customer's access at three sites:
'Site-1A', 'Site-1B', and 'Site-1C'. These sites are connected to
nodes that are mapped to node 1 (N1), node 2 (N2), and node 4 (N4)
in the underlying physical network. 'Site-1A' plays the role of
hub while 'Site-1B' and 'Site-1C' are configured as spoke.
VPN 2: This service supports any-to-any communications for
'customer 2' connecting the customer's access at two sites: 'Site-
2A' and 'Site-2B'. These sites are connected to nodes that are
mapped to nodes 1 (N1) and node 3 (N3)5 in the underlying physical
network. 'Site-2A' and 'Site-2B' have 'any-to-any' role.
Wu, et al. Expires January 7, 2022 [Page 6]
Internet-Draft Network and VPN Service PM YANG July 2021
4.2. Network Level
For network performance monitoring, the container of "networks" in
[RFC8345] do not need to be extended.
For VPN service performance monitoring, the container "service-type"
is defined to indicate the VPN type, e.g., L3VPN or Virtual Private
LAN Service (VPLS). The values are taken from
[I-D.ietf-opsawg-vpn-common]. When a network topology instance
contains the L3VPN or other L2VPN network type, it represents a VPN
instance that can perform performance monitoring.
This model defines the following set of network level attributes:
"vpn-id": Refers to an identifier of VPN service defined in
[I-D.ietf-opsawg-vpn-common]). This identifier is used to
correlate the performance status with the network service
configuration.
"vpn-service-topology": Indicates the type of VPN topology. This
model supports "any-to-any", "Hub and Spoke" (where Hubs can
exchange traffic), and "Hub and Spoke disjoint" (where Hubs cannot
exchange traffic) that are taken from
[I-D.ietf-opsawg-vpn-common]. These VPN topology types can be
used to describe how VPN sites communicate with each other.
module: ietf-network-vpn-pm
augment /nw:networks/nw:network/nw:network-types:
+--rw service-type!
+--rw service-type? identityref
augment /nw:networks/nw:network:
+--rw vpn-pm-attributes
+--rw vpn-id? vpn-common:vpn-id
+--rw vpn-service-topology? identityref
Figure 4: Network Level View of the Hierarchies
4.3. Node Level
For network performance monitoring, a container of "pm-attributes" is
augmented to the list of "node" that are defined in [RFC8345]. And
the leaf of "node-type" indicates the device type of Provider Edge
(PE), Provider (P) device, or Autonomous System Border Router (ASBR),
so that the performance metric between any two nodes each with
specific node type can be reported.
For VPN service performance monitoring, this model defines only the
following minimal set of node level network topology attributes:
Wu, et al. Expires January 7, 2022 [Page 7]
Internet-Draft Network and VPN Service PM YANG July 2021
"role": Defines the role in a particular VPN service topology. The
roles are taken from [I-D.ietf-opsawg-vpn-common] (e.g., any-to-
any-role, spoke-role, hub-role).
"vpn-summary-statistics": Lists a set of IPv4 statistics, IPv6
statistics, and MAC statistics. These statistics are specified
separately.
augment /nw:networks/nw:network/nw:node:
+--rw pm-attributes
+--rw node-type? identityref
+--rw role? identityref
+--ro vpn-summary-statistics
+--ro ipv4
| +--ro maximum-routes? uint32
| +--ro total-active-routes? uint32
+--ro ipv6
| +--ro maximum-routes? uint32
| +--ro total-active-routes? uint32
+--ro mac-num
+--ro mac-num-limit? uint32
+--ro total-active-mac-num? uint32
Figure 5: Node Level View of the Hierarchies
4.4. Link and Termination Point Level
The 'links' are classified into two types: topology link defined in
[RFC8345] and abstract link of a VPN between PEs.
The performance data of a link is a collection of counters that
report the performance status.
Wu, et al. Expires January 7, 2022 [Page 8]
Internet-Draft Network and VPN Service PM YANG July 2021
augment /nw:networks/nw:network/nt:link:
+--rw pm-attributes
+--rw low-percentile? percentile
+--rw middle-percentile? percentile
+--rw high-percentile? percentile
+--ro pm-source? string
+--ro reference-time? yang:date-and-time
+--ro measurement-interval? uint32
+--ro pm-statistics
| +--ro loss-statistics
| | +--ro packet-loss-count? yang:counter64
| | +--ro packet-reorder-count? yang:counter64
| | +--ro packets-out-of-seq-count? yang:counter64
| | +--ro packets-dup-count? yang:counter64
| | +--ro loss-ratio? percentage
| +--ro delay-statistics
| | +--ro direction? identityref
| | +--ro unit-value? identityref
| | +--ro min-delay-value? yang:gauge64
| | +--ro max-delay-value? yang:gauge64
| | +--ro low-delay-percentile? yang:gauge64
| | +--ro middle-delay-percentile? yang:gauge64
| | +--ro high-delay-percentile? yang:gauge64
| +--ro jitter-statistics
| +--ro unit-value? identityref
| +--ro min-jitter-value? yang:gauge32
| +--ro max-jitter-value? yang:gauge32
| +--ro low-jitter-percentile? yang:gauge32
| +--ro middle-jitter-percentile? yang:gauge32
| +--ro high-jitter-percentile? yang:gauge32
+--ro protocol-type? identityref
augment /nw:networks/nw:network/nw:node/nt:termination-point:
+--ro pm-statistics
+--ro inbound-octets? yang:counter64
+--ro inbound-unicast? yang:counter64
+--ro inbound-nunicast? yang:counter64
+--ro inbound-discards? yang:counter32
+--ro inbound-errors? yang:counter64
+--ro inbound-unknown-protocol? yang:counter64
+--ro outbound-octets? yang:counter64
+--ro outbound-unicast? yang:counter64
+--ro outbound-nunicast? yang:counter64
+--ro outbound-discards? yang:counter64
+--ro outbound-errors? yang:counter64
Figure 6: Link and Termination point Level View of the hierarchies
Wu, et al. Expires January 7, 2022 [Page 9]
Internet-Draft Network and VPN Service PM YANG July 2021
For the data nodes of 'link' depicted in Figure 6, the YANG module
defines the following minimal set of link-level performance
attributes:
Percentile parameters: The module supports reporting delay and
jitter metric by percentile values. By default, low percentile
(10th percentile), mid percentile (50th percentile), high
percentile (90th percentile) are used. Setting a percentile into
0.00 indicates the client is not interested in receiving
particular percentile. If all percentile nodes are set to 0.00,
this represents that no percentile related nodes will be reported
for a given performance metric (e.g. one-way delay, one-way delay
variation) and only peak/min values will be reported. For
example, a client can inform the server that it is interested in
receiving only high percentiles. Then for a given link, at a
given "reference-time" "measurement-interval", the 'high-delay-
percentile' and 'high-jitter-percentile' will be reported. An
example to illustrate the use of percentiles is provided in
Appendix A.3.
"pm-source": Indicates the performance monitoring source. The data
for the topology link can be based, e.g., on BGP-LS [RFC8571].
The statistics of the VPN abstract links can be collected based
upon VPN OAM mechanisms, e.g., OAM mechanisms specified in
[I-D.ietf-opsawg-l3sm-l3nm], or Ethernet service OAM specified in
[I-D.ietf-opsawg-l2nm]. Alternatively, the data can be based upon
the underlay technology OAM mechanisms, for example, GRE tunnel
OAM.
Loss Statistics: A set of loss statistics attributes that are used
to measure end to end loss between VPN sites or between any two
network nodes. The exact loss value or the loss percentage can be
reported.
Delay Statistics: A set of delay statistics attributes that are used
to measure end to end latency between VPN sites or between any two
network nodes. The peak/min values or percentile values can be
reported.
Jitter Statistics: A set of IP Packet Delay Variation [RFC3393]
statistics attributes that are used to measure end to end jitter
between VPN sites or between any two network nodes. The peak/min
values or percentile values can be reported.
"protocol-type": Indicates the abstract link protocol-type of a VPN,
such as GRE or IP-in-IP. The leaf refers to an identifier of the
"underlay-transport" defined in [I-D.ietf-opsawg-vpn-common],
Wu, et al. Expires January 7, 2022 [Page 10]
Internet-Draft Network and VPN Service PM YANG July 2021
which describes the transport technology to carry the traffic of
the VPN service.
For the data nodes of 'termination-point' depicted in Figure 6, the
module defines the following minimal set of statistics:
Inbound statistics: A set of inbound statistics attributes that are
used to measure the inbound statistics of the termination point,
such as received packets, received packets with errors, etc.
Outbound statistics: A set of outbound statistics attributes that
are used to measure the outbound statistics of the termination
point, such as sent packets, packets that could not be sent due to
errors, etc.
5. Network and VPN Service Performance Monitoring YANG Module
The "ietf-network-vpn-pm" module uses types defined in [RFC8345],
[RFC6991], and [RFC8532].
<CODE BEGINS> file "ietf-network-vpn-pm@2021-07-06.yang"
module ietf-network-vpn-pm {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm";
prefix nvp;
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Types";
}
import ietf-vpn-common {
prefix vpn-common;
reference
"RFC CCCC: A Layer 2/3 VPN Common YANG Model";
}
import ietf-network {
prefix nw;
reference
"RFC 8345: A YANG Data Model for Network
Topologies, Section 6.1";
}
import ietf-network-topology {
prefix nt;
reference
"RFC 8345: A YANG Data Model for Network
Topologies, Section 6.2";
}
Wu, et al. Expires January 7, 2022 [Page 11]
Internet-Draft Network and VPN Service PM YANG July 2021
import ietf-lime-time-types {
prefix lime;
reference
"RFC 8532: Generic YANG Data Model for the Management of
Operations, Administration, and Maintenance
(OAM) Protocols That Use Connectionless Communications";
}
organization
"IETF OPSAWG Working Group";
contact
"Editor: Qin Wu
<bill.wu@huawei.com>
Editor: Bo Wu
<lana.wubo@huawei.com>
Editor: Mohamed Boucadair
<mohamed.boucadair@orange.com>";
description
"This module defines a model for Network and VPN Service Performance
monitoring.
Copyright (c) 2021 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision 2021-07-06 {
description
"Initial revision.";
reference
"RFC XXXX: A YANG Model for Network and VPN Service Performance
Monitoring";
}
identity node-type {
description
"Base identity for node type";
}
identity pe {
Wu, et al. Expires January 7, 2022 [Page 12]
Internet-Draft Network and VPN Service PM YANG July 2021
base node-type;
description
"Identity for Provider Edge (PE) type.";
}
identity asbr {
base node-type;
description
"Identity for Autonomous System Border Router (ASBR) type.";
}
identity p {
base node-type;
description
"Identity for P type.";
}
identity direction {
description
"Base identity for measurement direction including
one-way measurement and two-way measurement.";
}
identity one-way {
base direction;
description
"Identity for one-way measurement.";
}
identity two-way {
base direction;
description
"Identity for two-way measurement.";
}
typedef percentage {
type decimal64 {
fraction-digits 5;
range "0..100";
}
description
"Percentage.";
}
typedef percentile {
type decimal64 {
fraction-digits 5;
}
Wu, et al. Expires January 7, 2022 [Page 13]
Internet-Draft Network and VPN Service PM YANG July 2021
description
"The percentile is a statistical value that indicates that a
certain percentage of a set of data falls below it.";
}
grouping vpn-summary-statistics {
description
"VPN Statistics grouping used for network topology
augmentation.";
container vpn-summary-statistics {
config false;
description
"Container for VPN summary statistics.";
container ipv4 {
leaf maximum-routes {
type uint32;
description
"Total routes for the VPN.";
}
leaf total-active-routes {
type uint32;
description
"Total active routes for the VPN.";
}
description
"IPv4-specific parameters.";
}
container ipv6 {
leaf maximum-routes {
type uint32;
description
"Total routes for the VPN.";
}
leaf total-active-routes {
type uint32;
description
"Total active routes for the VPN.";
}
description
"IPv6-specific parameters.";
}
container mac-num {
leaf mac-num-limit {
type uint32;
description
"Maximum number of MAC addresses.";
}
leaf total-active-mac-num {
Wu, et al. Expires January 7, 2022 [Page 14]
Internet-Draft Network and VPN Service PM YANG July 2021
type uint32;
description
"Total active MAC entries for the VPN.";
}
description
"MAC statistics.";
}
}
}
grouping link-error-statistics {
description
"Grouping for per link error statistics.";
container loss-statistics {
description
"Per link loss statistics.";
leaf packet-loss-count {
type yang:counter64;
description
"Total received packet drops count.";
}
leaf packet-reorder-count {
type yang:counter64;
description
"Total received packet reordered count.";
}
leaf packets-out-of-seq-count {
type yang:counter64;
description
"Total received out of sequence count.";
}
leaf packets-dup-count {
type yang:counter64;
description
"Total received packet duplicates count.";
}
leaf loss-ratio {
type percentage;
description
"Loss ratio of the packets. Express as percentage
of packets lost with respect to packets sent.";
}
}
}
grouping link-delay-statistics {
description
"Grouping for per link delay statistics";
Wu, et al. Expires January 7, 2022 [Page 15]
Internet-Draft Network and VPN Service PM YANG July 2021
container delay-statistics {
description
"Link delay summarised information. By default,
one way measurement protocol (e.g., OWAMP) is used
to measure delay.";
leaf direction {
type identityref {
base direction;
}
default "one-way";
description
"Define measurement direction including one way
measurement and two way measurement.";
}
leaf unit-value {
type identityref {
base lime:time-unit-type;
}
default "lime:milliseconds";
description
"Time units, where the options are s, ms, ns, etc.";
}
leaf min-delay-value {
type yang:gauge64;
description
"Minimum delay value observed.";
}
leaf max-delay-value {
type yang:gauge64;
description
"Maximum delay value observed.";
}
leaf low-delay-percentile {
type yang:gauge64;
description
"Low percentile of the delay observed with
specific measurement method.";
}
leaf middle-delay-percentile {
type yang:gauge64;
description
"Middle percentile of the delay observed with
specific measurement method.";
}
leaf high-delay-percentile {
type yang:gauge64;
description
"High percentile of the delay observed with
Wu, et al. Expires January 7, 2022 [Page 16]
Internet-Draft Network and VPN Service PM YANG July 2021
specific measurement method.";
}
}
}
grouping link-jitter-statistics {
description
"Grouping for per link jitter statistics";
container jitter-statistics {
description
"Link jitter summarised information. By default,
jitter is measured using IP Packet Delay Variation
(IPDV).";
leaf unit-value {
type identityref {
base lime:time-unit-type;
}
default "lime:milliseconds";
description
"Time units, where the options are s, ms, ns, etc.";
}
leaf min-jitter-value {
type yang:gauge32;
description
"Minimum jitter value observed.";
}
leaf max-jitter-value {
type yang:gauge32;
description
"Maximum jitter value observed.";
}
leaf low-jitter-percentile {
type yang:gauge32;
description
"Low percentile of the jitter observed.";
}
leaf middle-jitter-percentile {
type yang:gauge32;
description
"Middle percentile of the jitter observed.";
}
leaf high-jitter-percentile {
type yang:gauge32;
description
"High percentile of the jitter observed.";
}
}
}
Wu, et al. Expires January 7, 2022 [Page 17]
Internet-Draft Network and VPN Service PM YANG July 2021
grouping tp-svc-telemetry {
leaf inbound-octets {
type yang:counter64;
description
"The total number of octets received on the
interface, including framing characters.";
}
leaf inbound-unicast {
type yang:counter64;
description
"Inbound unicast packets were received, and delivered
to a higher layer during the last period.";
}
leaf inbound-nunicast {
type yang:counter64;
description
"The number of non-unicast (i.e., subnetwork-
broadcast or subnetwork-multicast) packets
delivered to a higher-layer protocol.";
}
leaf inbound-discards {
type yang:counter32;
description
"The number of inbound packets which were chosen
to be discarded even though no errors had been
detected to prevent their being deliverable to a
higher-layer protocol.";
}
leaf inbound-errors {
type yang:counter64;
description
"The number of inbound packets that contained
errors preventing them from being deliverable to a
higher-layer protocol.";
}
leaf inbound-unknown-protocol {
type yang:counter64;
description
"The number of packets received via the interface
which were discarded because of an unknown or
unsupported protocol.";
}
leaf outbound-octets {
type yang:counter64;
description
"The total number of octets transmitted out of the
interface, including framing characters.";
}
Wu, et al. Expires January 7, 2022 [Page 18]
Internet-Draft Network and VPN Service PM YANG July 2021
leaf outbound-unicast {
type yang:counter64;
description
"The total number of packets that higher-level
protocols requested be transmitted to a
subnetwork-unicast address, including those that
were discarded or not sent.";
}
leaf outbound-nunicast {
type yang:counter64;
description
"The total number of packets that higher-level
protocols requested be transmitted to a non-
unicast (i.e., a subnetwork-broadcast or
subnetwork-multicast) address, including those
that were discarded or not sent.";
}
leaf outbound-discards {
type yang:counter64;
description
"The number of outbound packets which were chosen
to be discarded even though no errors had been
detected to prevent their being transmitted. One
possible reason for discarding such a packet could
be to free up buffer space.";
}
leaf outbound-errors {
type yang:counter64;
description
"The number of outbound packets that contained
errors preventing them from being deliverable to a
higher-layer protocol.";
}
description
"Grouping for interface service telemetry.";
}
augment "/nw:networks/nw:network/nw:network-types" {
description
"Defines the service topologies types";
container service-type {
presence "Indicates Network service topology";
leaf service-type {
type identityref {
base vpn-common:service-type;
}
description
"The presence identifies the network service type,
Wu, et al. Expires January 7, 2022 [Page 19]
Internet-Draft Network and VPN Service PM YANG July 2021
e.g., L3VPN, VPLS, etc.";
}
description
"Container for VPN service type.";
}
}
augment "/nw:networks/nw:network" {
when 'nw:network-types/nvp:service-type' {
description
"Augment only for VPN Network topology.";
}
description
"Augment the network with service topology attributes";
container vpn-pm-attributes {
leaf vpn-id {
type vpn-common:vpn-id;
description
"VPN identifier.";
}
leaf vpn-service-topology {
type identityref {
base vpn-common:vpn-topology;
}
description
"VPN service topology, e.g., hub-spoke, any-to-any,
hub-spoke-disjoint";
}
description
"Container for vpn topology attributes.";
}
}
augment "/nw:networks/nw:network/nw:node" {
description
"Augment the network node with other general attributes";
container pm-attributes {
leaf node-type {
type identityref {
base node-type;
}
description
"Node type, e.g., PE, P, ASBR.";
}
description
"Container for node attributes.";
}
}
Wu, et al. Expires January 7, 2022 [Page 20]
Internet-Draft Network and VPN Service PM YANG July 2021
augment "/nw:networks/nw:network/nw:node/pm-attributes" {
when '../../nw:network-types/nvp:service-type' {
description
"Augment only for VPN node attributes.";
}
description
"Augment the network node with VPN specific attributes";
leaf role {
type identityref {
base vpn-common:role;
}
default "vpn-common:any-to-any-role";
description
"Role of the node in the VPN.";
}
uses vpn-summary-statistics;
}
augment "/nw:networks/nw:network/nt:link" {
description
"Augment the network topology link with performance monitoring
attributes";
container pm-attributes {
description
"Container for PM attributes.";
leaf low-percentile {
type percentile;
default "10.00";
description
"Low percentile to report. Setting low-percentile
into 0.00 indicates the client is not interested in receiving
low percentile.";
}
leaf middle-percentile {
type percentile;
default "50.00";
description
"Middle percentile to report. Setting middle-percentile
into 0.00 indicates the client is not interested in receiving
middle percentile.";
}
leaf high-percentile {
type percentile;
default "90.00";
description
"High percentile to report. Setting high-percentile
into 0.00 indicates the client is not interested in receiving
high percentile";
Wu, et al. Expires January 7, 2022 [Page 21]
Internet-Draft Network and VPN Service PM YANG July 2021
}
leaf pm-source {
type string;
config false;
description
"The OAM tool used to collect the PM data.";
}
leaf reference-time {
type yang:date-and-time;
config false;
description
"The time that the current Measurement Interval started.";
}
leaf measurement-interval {
type uint32;
units "seconds";
default "60";
config false;
description
"Interval to calculate performance metric.";
}
container pm-statistics {
config false;
uses link-error-statistics;
uses link-delay-statistics;
uses link-jitter-statistics;
description
"Container for service telemetry attributes.";
}
}
}
augment "/nw:networks/nw:network/nt:link/pm-attributes" {
when '../../nw:network-types/nvp:service-type' {
description
"Augment only for VPN Network topology.";
}
description
"Augment the network topology link with service performance
monitoring attributes";
leaf protocol-type {
type identityref {
base vpn-common:protocol-type;
}
config false;
description
"Underlay-transport type, e.g., GRE, LDP, etc.";
}
Wu, et al. Expires January 7, 2022 [Page 22]
Internet-Draft Network and VPN Service PM YANG July 2021
}
augment "/nw:networks/nw:network/nw:node/nt:termination-point" {
description
"Augment the network topology termination point with
performance monitoring attributes";
container pm-statistics {
config false;
uses tp-svc-telemetry;
description
"Container for termination point PM attributes.";
}
}
}
<CODE ENDS>
6. Security Considerations
The YANG modules defined in this document MAY be accessed via the
RESTCONF protocol [RFC8040] or NETCONF protocol [RFC6241]. The
lowest RESTCONF or NETCONF layer requires that the transport-layer
protocol provides both data integrity and confidentiality, see
Section 2 in [RFC8040] and [RFC6241]. The lowest NETCONF layer is
the secure transport layer, and the mandatory-to-implement secure
transport is Secure Shell (SSH)[RFC6242] . The lowest RESTCONF layer
is HTTPS, and the mandatory-to-implement secure transport is TLS
[RFC8446].
The NETCONF access control model [RFC8341] provides the means to
restrict access for particular NETCONF or RESTCONF users to a
preconfigured subset of all available NETCONF or RESTCONF protocol
operations and content.
There are a number of data nodes defined in this YANG module that are
writable/creatable/deletable (i.e., config true, which is the
default). These data nodes may be considered sensitive or vulnerable
in some network environments. Write operations (e.g., edit-config)
to these data nodes without proper protection can have a negative
effect on network operations. These are the subtrees and data nodes
and their sensitivity/vulnerability:
o /nw:networks/nw:network/svc-topo:svc-telemetry-attributes
o /nw:networks/nw:network/nw:node/svc-topo:node-attributes
Wu, et al. Expires January 7, 2022 [Page 23]
Internet-Draft Network and VPN Service PM YANG July 2021
7. IANA Considerations
This document requests IANA to register the following URI in the "ns"
subregistry within the "IETF XML Registry" [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
This document requests IANA to register the following YANG module in
the "YANG Module Names" subregistry [RFC6020] within the "YANG
Parameters" registry.
Name: ietf-network-vpn-pm
Namespace: urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm
Maintained by IANA: N
Prefix: nvp
Reference: RFC XXXX
8. Acknowledgements
Thanks to Joe Clarke, Adrian Farrel, Greg Mirsky, Roque Gagliano,
Erez Segev, and Dhruv Dhody for reviewing and providing important
input to this document.
9. Contributors
Michale Wang
Huawei
Email:wangzitao@huawei.com
Roni Even
Huawei
Email: ron.even.tlv@gmail.com
10. References
10.1. Normative References
[I-D.ietf-opsawg-vpn-common]
Barguil, S., Dios, O. G. D., Boucadair, M., and Q. Wu, "A
Layer 2/3 VPN Common YANG Model", draft-ietf-opsawg-vpn-
common-07 (work in progress), April 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>.
Wu, et al. Expires January 7, 2022 [Page 24]
Internet-Draft Network and VPN Service PM YANG July 2021
[RFC3393] Demichelis, C. and P. Chimento, "IP Packet Delay Variation
Metric for IP Performance Metrics (IPPM)", RFC 3393,
DOI 10.17487/RFC3393, November 2002,
<https://www.rfc-editor.org/info/rfc3393>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay
Measurement for MPLS Networks", RFC 6374,
DOI 10.17487/RFC6374, September 2011,
<https://www.rfc-editor.org/info/rfc6374>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
[RFC8345] Clemm, A., Medved, J., Varga, R., Bahadur, N.,
Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
2018, <https://www.rfc-editor.org/info/rfc8345>.
Wu, et al. Expires January 7, 2022 [Page 25]
Internet-Draft Network and VPN Service PM YANG July 2021
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[RFC8532] Kumar, D., Wang, Z., Wu, Q., Ed., Rahman, R., and S.
Raghavan, "Generic YANG Data Model for the Management of
Operations, Administration, and Maintenance (OAM)
Protocols That Use Connectionless Communications",
RFC 8532, DOI 10.17487/RFC8532, April 2019,
<https://www.rfc-editor.org/info/rfc8532>.
[RFC8641] Clemm, A. and E. Voit, "Subscription to YANG Notifications
for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641,
September 2019, <https://www.rfc-editor.org/info/rfc8641>.
10.2. Informative References
[I-D.ietf-opsawg-l2nm]
Barguil, S., Dios, O. G. D., Boucadair, M., and L. A.
Munoz, "A Layer 2 VPN Network YANG Model", draft-ietf-
opsawg-l2nm-02 (work in progress), April 2021.
[I-D.ietf-opsawg-l3sm-l3nm]
Barguil, S., Dios, O. G. D., Boucadair, M., Munoz, L. A.,
and A. Aguado, "A Layer 3 VPN Network YANG Model", draft-
ietf-opsawg-l3sm-l3nm-08 (work in progress), April 2021.
[RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
RFC 5357, DOI 10.17487/RFC5357, October 2008,
<https://www.rfc-editor.org/info/rfc5357>.
[RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S.
Previdi, "OSPF Traffic Engineering (TE) Metric
Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015,
<https://www.rfc-editor.org/info/rfc7471>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[RFC8194] Schoenwaelder, J. and V. Bajpai, "A YANG Data Model for
LMAP Measurement Agents", RFC 8194, DOI 10.17487/RFC8194,
August 2017, <https://www.rfc-editor.org/info/rfc8194>.
[RFC8309] Wu, Q., Liu, W., and A. Farrel, "Service Models
Explained", RFC 8309, DOI 10.17487/RFC8309, January 2018,
<https://www.rfc-editor.org/info/rfc8309>.
Wu, et al. Expires January 7, 2022 [Page 26]
Internet-Draft Network and VPN Service PM YANG July 2021
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
[RFC8570] Ginsberg, L., Ed., Previdi, S., Ed., Giacalone, S., Ward,
D., Drake, J., and Q. Wu, "IS-IS Traffic Engineering (TE)
Metric Extensions", RFC 8570, DOI 10.17487/RFC8570, March
2019, <https://www.rfc-editor.org/info/rfc8570>.
[RFC8571] Ginsberg, L., Ed., Previdi, S., Wu, Q., Tantsura, J., and
C. Filsfils, "BGP - Link State (BGP-LS) Advertisement of
IGP Traffic Engineering Performance Metric Extensions",
RFC 8571, DOI 10.17487/RFC8571, March 2019,
<https://www.rfc-editor.org/info/rfc8571>.
[RFC8969] Wu, Q., Ed., Boucadair, M., Ed., Lopez, D., Xie, C., and
L. Geng, "A Framework for Automating Service and Network
Management with YANG", RFC 8969, DOI 10.17487/RFC8969,
January 2021, <https://www.rfc-editor.org/info/rfc8969>.
Appendix A. Illustrating Examples
A.1. Example of Pub/Sub Retrieval
The example shown in Figure 7 illustrates how a client subscribes to
the performance monitoring information between nodes ('node-id') A
and B in the L3 network topology. The performance monitoring
parameter that the client is interested in is end-to-end loss.
<rpc netconf:message-id="101"
xmlns:netconf="urn:ietf:params:xml:ns:netconf:base:1.0">
<establish-subscription
xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications">
<stream-subtree-filter>
<networks
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topo">
<network>
<network-id>l3-network</network-id>
<service-type
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
L3VPN
</service-type>
<node>
<node-id>A</node-id>
<pm-attributes>
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
<node-type>pe</node-type>
Wu, et al. Expires January 7, 2022 [Page 27]
Internet-Draft Network and VPN Service PM YANG July 2021
</pm-attributes>
<termination-point
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topology">
<tp-id>1-0-1</tp-id>
<pm-statistics
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
<inbound-octets>150</inbound-octets>
<outbound-octets>100</outbound-octets>
</pm-statistics>
</termination-point>
</node>
<node>
<node-id>B</node-id>
<pm-attributes>
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
<node-type>pe</node-type>
</pm-attributes>
<termination-point
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topology">
<tp-id>2-0-1</tp-id>
<pm-statistics
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
<inbound-octets>150</inbound-octets>
<outbound-octets>100</outbound-octets>
</pm-statistics>
</termination-point>
</node>
<link
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topology">
<link-id>A-B</link-id>
<source>
<source-node>A</source-node>
</source>
<destination>
<dest-node>B</dest-node>
</destination>
<protocol-type>mpls-te</protocol-type>
<pm-attributes
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
<loss-statistics>
<packet-loss-count>100</packet-loss-count>
</loss-statistics>
</pm-attributes>
</link>
</network>
</networks>
</stream-subtree-filter>
<period
Wu, et al. Expires January 7, 2022 [Page 28]
Internet-Draft Network and VPN Service PM YANG July 2021
xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-push:1.0">
500
</period>
</establish-subscription>
</rpc>
Figure 7: Pub/Siub Retrieval
A.2. Example of RPC-based Retrieval
This example, depicted in Figure 8, illustrates how a the client can
use the RPC model to fetch performance data on demand. For example,
the client requests "packet-loss-count" between 'source-node' A and
'dest-node' B that belong to the same VPN ('VPN1').
<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
message-id="1">
<report
xmlns="urn:ietf:params:xml:ns:yang:example-service-pm-report">
<networks xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topo">
<network>
<network-id>vpn1</network-id>
<node>
<node-id>A</node-id>
<pm-attributes
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
<node-type>pe</node-type>
</pm-attribtues>
<termination-point
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topology">
<tp-id>1-0-1</tp-id>
<pm-statistics
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
<inbound-octets>100</inbound-octets>
<outbound-octets>150</outbound-octets>
</pm-statistics>
</termination-point>
</node>
<node>
<node-id>B</node-id>
<pm-attributes
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
<node-type>pe</node-type>
</pm-attribtues>
<termination-point
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-topology">
<tp-id>2-0-1</tp-id>
<pm-statistics
Wu, et al. Expires January 7, 2022 [Page 29]
Internet-Draft Network and VPN Service PM YANG July 2021
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm">
<inbound-octets>150</inbound-octets>
<outbound-octets>100</outbound-octets>
</pm-statistics>
</termination-point>
</node>
<link>
<link-id>A-B</link-id>
<source>
<source-node>A</source-node>
</source>
<destination>
<dest-node>B</dest-node>
</destination>
<-type>mpls-te</link-type>
<pm-attributes
xmlns="urn:ietf:params:xml:ns:yang:ietf-network-pm">
<loss-statistics>
<packet-loss-count>120</packet-loss-count>
</loss-statistics>
</pm-attributes>
</link>
</network>
</report>
</rpc>
Figure 8
A.3. Example of Percentile Monitoring
The following shows an example of a percentile measurement for a VPN
link.
Wu, et al. Expires January 7, 2022 [Page 30]
Internet-Draft Network and VPN Service PM YANG July 2021
{
"ietf-network-topology:link":[
{
"link-id":"vpn1-link1",
"source":{
"source-node":"vpn-node1"
},
"destination":{
"dest-node":"vpn-node3"
},
"ietf-network-vpn-pm:protocol-type":"gre",
"ietf-network-vpn-pm:pm-attributes":{
"low-percentile":"20.00",
"middle-percentile":"50.00",
"high-percentile":"90.00",
"pm-statistics:delay-statistics":{
"direction":"one-way",
"unit-values":"milliseconds",
"min-delay-value":"43",
"max-delay-value":"99",
"low-delay-percentile":"64",
"middle-delay-percentile":"77",
"high-delay-percentile":"98"
}
}
}
]
}
Authors' Addresses
Bo Wu (editor)
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: lana.wubo@huawei.com
Qin Wu (editor)
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: bill.wu@huawei.com
Wu, et al. Expires January 7, 2022 [Page 31]
Internet-Draft Network and VPN Service PM YANG July 2021
Mohamed Boucadair (editor)
Orange
Rennes 35000
France
Email: mohamed.boucadair@orange.com
Oscar Gonzalez de Dios
Telefonica
Madrid
ES
Email: oscar.gonzalezdedios@telefonica.com
Bin Wen
Comcast
Email: bin_wen@comcast.com
Change Liu
China Unicom
Email: liuc131@chinaunicom.cn
Honglei Xu
China Telecom
Email: xuhl.bri@chinatelecom.cn
Wu, et al. Expires January 7, 2022 [Page 32]
