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]. 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 Editor: Bo Wu Editor: Mohamed Boucadair "; 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."; } } } 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, . 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, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [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, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay Measurement for MPLS Networks", RFC 6374, DOI 10.17487/RFC6374, September 2011, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [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, . 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, . [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, . [RFC8641] Clemm, A. and E. Voit, "Subscription to YANG Notifications for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641, September 2019, . 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, . [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, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8194] Schoenwaelder, J. and V. Bajpai, "A YANG Data Model for LMAP Measurement Agents", RFC 8194, DOI 10.17487/RFC8194, August 2017, . [RFC8309] Wu, Q., Liu, W., and A. Farrel, "Service Models Explained", RFC 8309, DOI 10.17487/RFC8309, January 2018, . 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, . [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, . [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, . [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, . 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. l3-network L3VPN A xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm"> pe Wu, et al. Expires January 7, 2022 [Page 27] Internet-Draft Network and VPN Service PM YANG July 2021 1-0-1 150 100 B xmlns="urn:ietf:params:xml:ns:yang:ietf-network-vpn-pm"> pe 2-0-1 150 100 A-B A B mpls-te 100 500 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'). vpn1 A pe 1-0-1 100 150 B pe 2-0-1 150 100 A-B A B <-type>mpls-te 120 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]