]> ETRI

byyun@etri.re.kr

woori-net

young@woori-net.com

Routing CCAMP Working Group performance monitoring streaming transport YANG This document applies the core Performance Monitoring (PM) collection and interval-capabilities YANG data models to common transport equipment. It defines a YANG module of transport performance parameter identities, derived from the base identity of the PM collection model; it specifies the three transport parameter profiles of ITU-T G.7710 normatively; and it gives end-to-end examples that show capability discovery followed by YANG-Push subscription, notification, and threshold reporting for a transport profile. The latest revision of this draft can be found at . Status information for this document may be found at . Discussion of this document takes place on the Common Control and Measurement Plane Working Group mailing list (), which is archived at . Subscribe at . Source for this draft and an issue tracker can be found at . Please replace "RFC XXXX" with the RFC number assigned to this document, and "RFC YYYY" with the RFC number assigned to , throughout this document and in the YANG module, and remove this note.

Introduction Performance Monitoring (PM) data generated by a transport Network Element (NE) is processed into summarized statistics and delivered to external clients. The continuous, push-based delivery of that data is referred to in this document as PM streaming. This document depends on two core documents that define the technology-neutral models used here. The PM collection data model defines the performance parameter structure, the sampling and collection interval hierarchy, the three collection types (counts, snapshot, and tidemarks), and the threshold-event notification. The interval-capabilities model lets a server advertise which intervals, measurement methods, and collection types it supports. Both models are generic and neutral to the transport technology. This document specifies how those generic models are applied to common transport equipment. It defines a YANG module of the transport performance parameters as identities, specifies the three transport profiles of ITU-T G.7710 normatively, and gives end-to-end examples of capability discovery, subscription, notification, and threshold reporting. This document does not define any new subscription or notification mechanism; the collected data and events are carried using the YANG-Push framework .

Terminology The term "client" refers to any consumer of the PM streaming interface of a transport NE, such as an operations system (OS), a Physical Network Controller (PNC), a network digital twin (NDT), or an AI-driven application. The term "transport" is used in the sense of and covers technologies such as OTN, MPLS-TP, and transport Ethernet. The tree diagrams in this document use the notation defined in . 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 when, and only when, they appear in all capitals, as shown here.

Relationship to the Core Documents This document is a technology-specific document that depends on the two core documents, as shown in . Other technology-specific documents can depend on the core documents in the same way.

The documents play distinct, layered roles: (1) The PM collection model (module ietf-pm-collection) is the generic, transport-neutral core: the performance parameter structure and the "performance-parameter" base identity, the sampling and collection interval hierarchy, the three collection types (counts, snapshot, and tidemarks), and the threshold-event notification. (2) The PM interval-capabilities model (module ietf-pm-interval-capabilities) imports the profile-names type and the performance-parameter identity from (1) and augments the "ietf-system-capabilities" module of , so that a server can advertise which sampling and collection intervals, measurement methods, and collection types it supports at the standard capability discovery anchor. (3) This document (module ietf-pm-parameters) defines the transport-specific PM parameter identities, derived from the "performance-parameter" base identity of (1); specifies the transport profiles (see ); and shows how the three modules are used together when PM data is streamed from common transport equipment. This document's YANG module imports module (1) for the "performance-parameter" base identity; it does not import module (2). A "pm-parameter" entry of (1) identifies its parameter by one of the identities defined here, so that the parameter values collected under (1), and the capabilities advertised under (2), are interpreted using these identities. The normative collection and capability semantics remain in and ; this document adds the transport-specific parameter module (see ), the normative definition of the transport profiles, and the applicability guidance.

Placement in the Transport Network Element The generic models are implemented within the Equipment Management Function (EMF) of a transport NE, as defined in ITU-T G.7710 . The PM collection model provides the data structures, the interval-capabilities model advertises the supported intervals, and the transport parameter module defined in this document (see ) identifies the transport parameters that the profiles refer to. The data is exposed at the NE management interface and consumed by remote clients, as illustrated in .

Transport Common PM Parameters and Profiles Metric values of PM parameters are measured for maintenance and QoS monitoring over transport networks. Quality of Service (QoS) parameters assess the network's long-term ability to deliver agreed-upon service quality. They verify performance against contractual obligations defined in service-level agreements (SLAs) over longer intervals (24 hours, monthly periods). By simultaneously measuring both directions of a bidirectional connection, QoS parameters provide a holistic view of the sustained quality experienced by users. Maintenance parameters focus on short-term monitoring and detailed analysis for operational reliability. Over intervals such as 15 minutes or 24 hours, they enable swift responses to intermittent faults, bursts of errors, and subtle performance changes. Maintenance parameters typically involve unidirectional analysis, where each direction of transmission is monitored independently. This approach helps operators precisely pinpoint faults, troubleshoot intermittent issues, and perform preventive maintenance effectively.

Transport PM Parameters The PM parameters of common transport equipment defined in are listed below, together with the identity by which each is referred to in the "pm-parameter" list of . Additional parameters may be needed for packet networks and can be defined in the same way by deriving further identities from "performance-parameter". Parameter Identity Description ES pm-pa:es Errored Seconds SES pm-pa:ses Severely Errored Seconds BBE pm-pa:bbe Background Block Errors BBC pm-pa:bbc Background Block Count UAS pm-pa:uas Unavailable Seconds SEP pm-pa:sep Severely Errored Period PJE pm-pa:pje Pointer Justification Events All of the transport PM parameters listed above are obtained by passive measurement in the sense of : they are derived from protocol counters and physical-layer signals already present on the monitored connection, without generating synthetic test traffic. When these parameters are configured through the PM collection model , the optional "measurement-method" leaf of each "pm-parameter" is therefore set to "passive". According to collection types, purposes, and time intervals, different parameters are used. The following three transport profiles, named using the profile-naming format of the PM collection model , provide comprehensive coverage for maintenance and QoS monitoring across different temporal resolutions. The "transport" network token indicates that a profile applies across multiple transport technologies (for example OTN, MPLS-TP, and transport Ethernet). The normative definition of the profiles is given in .

itu-transport-maintenance-15min Profile The "itu-transport-maintenance-15min" profile is designed for short-term operational monitoring and rapid fault detection. It uses all three collection types (counts, snapshot, and tidemarks) over 15-minute intervals. The profile includes core maintenance parameters: ES, SES, BBE, BBC, and UAS. The 15-minute interval enables operators to quickly detect and respond to performance degradation, making it ideal for proactive maintenance and immediate troubleshooting. The combination of counts (for cumulative event tracking), snapshot (for instantaneous state capture), and tidemarks (for extreme value monitoring) provides a comprehensive view of network behaviour within each collection interval. This profile is particularly valuable for network operations centres (NOCs) requiring real-time visibility into transport network health and for automated systems that need to trigger immediate responses to performance anomalies.

itu-transport-maintenance-24hr Profile The "itu-transport-maintenance-24hr" profile extends maintenance monitoring to longer-term analysis and trend identification. Like the 15-minute profile, it employs all three collection types (counts, snapshot, and tidemarks) but over 24-hour intervals. The parameter set includes ES, SES, BBE, BBC, UAS, and additionally PJE. The 24-hour interval allows for comprehensive daily performance analysis, enabling operators to identify patterns, trends, and recurring issues not apparent in shorter intervals. The inclusion of PJE provides additional insight into synchronisation-related performance issues that are more relevant over longer observation periods. This profile supports strategic maintenance planning, capacity management, and historical performance analysis. It complements the 15-minute profile by providing the broader context needed for long-term network optimisation and preventive maintenance strategies.

itu-transport-qos-24hr Profile The "itu-transport-qos-24hr" profile is designed for QoS monitoring and SLA compliance verification. Unlike the maintenance profiles, it focuses exclusively on the counts collection type over 24-hour intervals, emphasising sustained performance assessment rather than detailed operational monitoring. The parameter set includes ES, SES, BBE, BBC, SEP, and UAS. The exclusive use of counts reflects its focus on cumulative performance over extended periods, which is essential for SLA compliance and service quality reporting. The 24-hour interval aligns with typical SLA measurement periods and provides the statistical basis for service quality assessments. The inclusion of SEP is particularly relevant for QoS monitoring as it represents sustained periods of degraded performance that directly impact service quality commitments.

Profile Relationships and Operational Integration These three profiles work together to provide a comprehensive performance monitoring framework. The "itu-transport-maintenance-15min" profile serves as the primary operational tool for immediate network management, while the "itu-transport-maintenance-24hr" profile provides the analytical foundation for strategic planning and trend analysis. The "itu-transport-qos-24hr" profile ensures that service quality commitments are met and provides the data necessary for SLA reporting and customer assurance. The hierarchical relationship between these profiles enables operators to correlate short-term operational events with long-term performance trends and service quality metrics. For example, a spike in ES detected by the 15-minute maintenance profile can be correlated with daily trends from the 24-hour maintenance profile and assessed against SLA thresholds defined in the QoS profile. This integrated approach supports both reactive troubleshooting and proactive network optimisation while ensuring compliance with service quality commitments.

Transport Profile Definitions The three transport profiles are defined in , which follows . Each profile is an entry of the "parameter-profile" list of , keyed by the profile name, containing one "pm-parameter" entry for each listed parameter. Each "pm-parameter" entry has a "sampling-interval" entry and, within it, a "collection-interval" of the listed duration under which the listed collection types are enabled; its "measurement-method" is "passive". Profile Parameters Collection types Sampling interval (default) Collection interval itu-transport-maintenance-15min es, ses, bbe, bbc, uas counts 1 second 15 minutes itu-transport-maintenance-24hr es, ses, bbe, bbc, uas, pje counts 1 second 24 hours itu-transport-qos-24hr es, ses, bbe, bbc, uas, sep counts 1 second 24 hours Collection is always performed on sampled values, so every profile entry has a sampling interval. The sampling interval in is the default. A server MAY provide a transport profile entry as system-defined configuration, in which case it is present in the operational datastore with origin "system" without client configuration. A server MAY additionally support other collection intervals for the parameters of a profile, as advertised through ; the sampling and collection intervals in are the defaults of the transport profiles.

Transport Parameter Module The following module defines the transport performance parameters as identities derived from "pm-co:performance-parameter" of . The module defines no data nodes, so it has no tree diagram; its identities are summarised in . Statement Name Base / reference identity es, ses, bbe, bbc, uas, pje, sep pm-co:performance-parameter

Editor: Bin Yeong Yoon "; description "This YANG module defines the performance monitoring (PM) parameters of common transport equipment, based on ITU-T G.7710, as identities derived from the performance-parameter base identity of ietf-pm-collection. The three transport parameter profiles (itu-transport-maintenance-15min, itu-transport-maintenance-24hr, and itu-transport-qos-24hr) are instances of the parameter-profile list of ietf-pm-collection. Copyright (c) 2026 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 Revised BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices."; revision 2026-10-29 { description "Initial revision."; reference "RFC XXXX: A YANG Data Model for Performance Monitoring Streaming on Common Transport Equipment"; } /* * IDENTITIES: transport performance parameters */ identity es { base pm-co:performance-parameter; description "Errored Second (ES)."; reference "ITU-T G.7710"; } identity ses { base pm-co:performance-parameter; description "Severely Errored Second (SES)."; reference "ITU-T G.7710"; } identity bbe { base pm-co:performance-parameter; description "Background Block Error (BBE)."; reference "ITU-T G.7710"; } identity bbc { base pm-co:performance-parameter; description "Background Block Count (BBC)."; reference "ITU-T G.7710"; } identity uas { base pm-co:performance-parameter; description "Unavailable Second (UAS)."; reference "ITU-T G.7710"; } identity pje { base pm-co:performance-parameter; description "Pointer Justification Event (PJE)."; reference "ITU-T G.7710"; } identity sep { base pm-co:performance-parameter; description "Severely Errored Period (SEP)."; reference "ITU-T G.7710"; } } ]]>

Use Cases: Streaming a Transport Profile This section shows the end-to-end flow for a transport profile, from capability discovery to subscription, notification, and threshold reporting. The examples use the SES parameter ("pm-pa:ses") of the "itu-transport-maintenance-15min" profile.

Step 1: Discover Supported Intervals The client first reads the interval capabilities for the parameter, to learn which sampling and collection intervals, and which collection types, the transport NE supports. These capabilities are advertised by augmenting the "ietf-system-capabilities" container of , so the client retrieves them under "system-capabilities", the same anchor used for subscription and notification capabilities. The client uses a NETCONF <get-data> request on the operational datastore, as shown in ; the subtree filter selects the parameter by its list keys, so the whole entry is returned.

ds:operational itu-transport-maintenance-15min pm-pa:ses ]]>

shows the "pm-interval-capabilities" data returned within "system-capabilities" in the reply.

itu-transport-maintenance-15min pm-pa:ses counts 1s 1 1 second 1 second 1 collection-range 5 1440 minute 15 minute 5 1 ]]>

The reply shows that the NE supports 1-second sampling and a collection interval range of 5 to 1440 minutes with 5-minute granularity, defaulting to 15 minutes, and that it supports the counts collection type for the parameter, and that it retains the most recently completed collection interval. The client therefore selects a 1-second sampling interval, a 15-minute collection interval, and the counts collection type, which the NE supports.

Step 2: Subscribe to Periodic Collection Data Using the supported intervals, the client establishes a periodic YANG-Push subscription to the counts collection value in the operational datastore. The period is expressed in centiseconds and is set to 90000 (900 seconds), so that an update is sent once per 15-minute collection interval.

ds:operational /pm-co:pm-periodic-collection/ parameter-profile[name='itu-transport-maintenance-15min']/ pm-parameter[name='pm-pa:ses']/ sampling-interval[id='1s']/ collection-interval[id='15min']/ collection-types/counts/collection-value encode-xml 90000 2026-07-01T00:00:00Z ]]>

Step 3: Receive Periodic Updates Once per period the NE sends a "push-update" notification for the subscription, whose identifier returned by the NE is 39. The update contains the selected data only. The collected value of 5 is the total severely errored seconds in the period.

2026-07-01T00:15:00Z 39 itu-transport-maintenance-15min pm-pa:ses 1s 15min 5 ]]>

Step 4: Threshold Reporting The client can also subscribe to threshold events. Threshold events are YANG notifications, not datastore data, so the client subscribes to an event stream, here the "NETCONF" event stream, using subscribed notifications , without a datastore or a period. When the counts value crosses the configured transient threshold during the interval, a Threshold Report is delivered using the "pm-threshold-events" notification of the PM collection model. No transport-specific event mechanism is required.

NETCONF /pm-co:pm-threshold-events encode-xml ]]>

2026-07-01T00:09:00Z itu-transport-maintenance-15min pm-pa:ses 1s 15min Threshold-Crossed-Event true 2026-07-01T00:09:00Z ]]>

Streaming Considerations for Transport Equipment On transport equipment the following points apply. Collection intervals should align with the NE clock source so that interval boundaries are consistent across the network and snapshots taken at a uniform time can be correlated across NEs. A transport NE may serve many parameters across many monitored objects (links, tunnels, equipment sensors), so operators should consider the load of large numbers of concurrent subscriptions and choose profiles and intervals accordingly. Threshold events, both periodic and the non-periodic BUT, EUT, and CSES events, are carried in the notification defined by the PM collection model.

Open Issues This section is to be removed before publication. The representation of the transport profiles in YANG is left for discussion in the Working Group. The profile contents (parameters, collection types, and default intervals) are given in . What remains open is how a server indicates the profiles it supports, and how the applicability of each parameter to a given transport layer is expressed. Candidates, none of which requires changes to the core documents, include one YANG feature per profile advertised in the YANG library , the profiles published as YANG instance data , and the capability advertisement of .

Security Considerations The YANG module defined in this document defines only identities; it defines no data nodes, RPCs, actions, or notifications, and therefore introduces no new data that could be read, written, or delivered through network management protocols. The identities defined here are used as values of the "pm-parameter" name leaf of and of ; the security considerations of those documents apply to the data nodes in which these identities appear. Those data nodes are designed to be accessed via NETCONF or RESTCONF over a secure transport such as SSH, with access restricted using the Network Configuration Access Control Model (NACM) . The security considerations of the YANG-Push framework also apply. The exposed performance and capability data can reveal information about the transport network; operators may wish to restrict access accordingly.

IANA Considerations This document requests IANA to register the following URI in the "ns" subregistry within the "IETF XML Registry":

This document requests IANA to register the following YANG module in the "YANG Module Names" registry :

YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK] The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices. It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized as remote procedure calls (RPCs). This document obsoletes RFC 4741. [STANDARDS-TRACK] YANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols. This document describes the syntax and semantics of version 1.1 of the YANG language. YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification. There are a small number of backward incompatibilities from YANG version 1. This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF). This document captures the current syntax used in YANG module tree diagrams. The purpose of this document is to provide a single location for this definition. This syntax may be updated from time to time based on the evolution of the YANG language. The standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability. There is a need for standard mechanisms to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. This document defines such an access control model. This document obsoletes RFC 6536. This document defines a YANG data model and associated mechanisms enabling subscriber-specific subscriptions to a publisher's event streams. Applying these elements allows a subscriber to request and receive a continuous, customized feed of publisher-generated information. This document provides a Network Configuration Protocol (NETCONF) binding to the dynamic subscription capability of both subscribed notifications and YANG-Push. This document describes a mechanism that allows subscriber applications to request a continuous and customized stream of updates from a YANG datastore. Providing such visibility into updates enables new capabilities based on the remote mirroring and monitoring of configuration and operational state. ETRI woori-net This document specifies a YANG data model for Collection Measurement based on the Performance Management (PM) Collection function requirements defined in ITU-T G.7710. The model processes raw performance data sampled at a network node and produces structured data that can be retrieved by clients via pull-based mechanisms or delivered via push-based mechanisms such as YANG-Push. This document does not define new performance metrics; the base metrics are those of the IPPM framework, and the model specifies the collection and exposure of the operationally important subset identified by ITU-T G.7710. ETRI woori-net This document defines a YANG data model, "ietf-pm-interval- capabilities", that enables a server to advertise which collection intervals it can support. A client reads this capability information before configuring performance measurements, so that it selects only sampling and collection intervals that the server can honour. The capabilities are advertised by augmenting the "ietf-system- capabilities" module defined in [RFC9196], so that a client discovers them at the same well-known location used for subscription and notification capabilities. The model imports the "profile-names" type from the companion collection measurement model defined in [I-D.yoon-ippm-collection-measure] and mirrors its profile-and- parameter structure, ensuring direct alignment between capability discovery and measurement configuration. The model does not define measurement data structures or any delivery mechanism; those are defined in the companion document. ITU-T In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. This memo provides clear definitions for Active and Passive performance assessment. The construction of Metrics and Methods can be described as either "Active" or "Passive". Some methods may use a subset of both Active and Passive attributes, and we refer to these as "Hybrid Methods". This memo also describes multiple dimensions to help evaluate new methods as they emerge. This document describes a YANG library that provides information about the YANG modules, datastores, and datastore schemas used by a network management server. Simple caching mechanisms are provided to allow clients to minimize retrieval of this information. This version of the YANG library supports the Network Management Datastore Architecture (NMDA) by listing all datastores supported by a network management server and the schema that is used by each of these datastores. This document extends the Network Configuration Protocol (NETCONF) defined in RFC 6241 in order to support the Network Management Datastore Architecture (NMDA) defined in RFC 8342. This document updates RFCs 6241 and 7950. The update to RFC 6241 adds new and operations and augments existing,, and operations. The update to RFC 7950 requires the usage of the YANG library (described in RFC 8525) by NETCONF servers implementing the NMDA. Datastores are a fundamental concept binding the data models written in the YANG data modeling language to network management protocols such as the Network Configuration Protocol (NETCONF) and RESTCONF. This document defines an architectural framework for datastores based on the experience gained with the initial simpler model, addressing requirements that were not well supported in the initial model. This document updates RFC 7950. This document defines two YANG modules, "ietf-system-capabilities" and "ietf-notification-capabilities". The module "ietf-system-capabilities" provides a placeholder structure that can be used to discover YANG-related system capabilities for servers. The module can be used to report capability information from the server at runtime or at implementation time by making use of the YANG instance data file format. The module "ietf-notification-capabilities" augments "ietf-system-capabilities" to specify capabilities related to "Subscription to YANG Notifications for Datastore Updates" (RFC 8641). There is a need to document data defined in YANG models at design time, implementation time, or when a live server is unavailable. This document specifies a standard file format for YANG instance data, which follows the syntax and semantics of existing YANG models and annotates it with metadata.

Contributors KT

kwangkoog.lee@kt.com

SK Telecom

jongyoon.shin@sk.com

LGU+

sy.nam@lguplus.co.kr