Extensible YANG Model for Network Telemetry Messages

Introduction Nowadays network operators are using machine and human readable YANG to model their configurations and obtain YANG modelled operational data from their networks. Network operators organize their data in a Data Mesh where a message broker such as Apache Kafka or RabbitMQ facilitates the exchange of messages among data processing components. Today, subscribing to a YANG datastore, publishing a YANG modeled notifications message from the network and viewing the data in a time series database, manual labor is needed to perform data transformation to make a message broker and its data processing components with YANG notifications interoperable. Even though YANG is intented to ease data management, this promise has not yet been fulfilled for Network Telemetry. An Architecture for YANG-Push to Message Broker Integration defined an architecture for integrating YANG-Push with message brokers for a Data Mesh architecture. How the notification messages at a YANG-Push receiver is being transformed to the message broker is being described in Section , however the produced message format left unspecified. The message could be published as it was received from the network to their organization's message broker. However, this approach is insufficient for correct human and automated understanding of the data generated by the network. This insufficiency stems from not presenting a holistic picture along with the data generated by the network. In particular, when a data consumer in the data mesh consumes a YANG message from their organization's message broker, they cannot answer simple questions such as:

Which network operating system collected the data?
To which network platform belongs the network node?
What is the subscribed xpath, sub-tree filter and its schema reference?
When did the data collection received the data?
What additional metadata is necessary for a consumer to make sense of the data?

This document defines a standard YANG envelope message to carry with the collected Network Telemetry notifications the provenance and metadata information for a YANG data exchanged in message brokers for a Data Mesh architecture.

Requirements Language 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. The terms "subscriber", "publisher", and "receiver" are used as defined in . In addition, this document reuses the terms defined in for the use in message broker enviroment: Notification Metadata: Additional data describing the context of a notification that is sent in each message, e.g. which node generated the messsage or at which time the notification was published. Notification Envelope: YANG structure encapsulating the payload of a notification, allowing the inclusion of metadata.

YANG Module The extensible YANG module for Network Telemetry messages defines an envelope message schema which adds four metadata categories to the collected Network Telemetry notifications.

Network Node Provenance:: The "network-node-manifest" container in "ietf-telemetry-message" contains the provenance information about the network node that published YANG notifications to the receiver. This category adds metadata such as the node name, address, and software version to the message.

Data Collection Provenance:: The "data-collection-metadata" container in "ietf-telemetry-message" contains the provenance information about the data collection. The data type is the same as the first category but specific to the collector node.

Data Collection Protocol Provenance:: The "session-protocol" container in "ietf-telemetry-message" contains the session information about the session between the collector and the network node. This category adds fields such as the session protocol and the time the event was generated in the network node. Moreover, this document defines an extension specific to YANG-Push that includes YANG-Push subscription information.

Network Operator Provenance:: The optional labels list in the "data-collection-metadata" container in "ietf-telemetry-message" contains the operator specific metadata. Some operators enrich the collected data with specific information. For instance: type of the network node (provider or provider edge node) or which operational unit the node is operated by. For this purpose the document defines a generic metadata map with key/values that can be used freely by the network operator.

+--ro payload? ]]>

Thomas Graf "; description "This YANG modules defines a model for a telemetry collector to send collected YANG data from the network. Copyright (c) 2025 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; see the RFC itself for full legal notices."; revision 2025-04-17 { description "Initial revision."; reference "RFC XXXX"; } identity session-protocol { description "Base identity to represent session protocols."; } identity yp-push { base session-protocol; description "YANG-Push in RFC 8640 or RFC 8641 or RFC 8650."; reference "RFC 8640, RFC 8641, RFC 8650: YANG-Push Events and Notifications for Datastores."; } identity netconf { base session-protocol; description "NETCONF RPC as described in RFC 6241."; reference "RFC 6241: NETCONF RPC."; } identity restconf { base session-protocol; description "RESTCONF HTTP as described in RFC 8040."; reference "RFC 8040."; } typedef telemetry-notification-event-type { type enumeration { enum log { description "Collector is reporting the event as it arrived from the network element."; } enum update { description "Collector has updated an entry inside its local cache. This could be triggered by an event from the network for instance interface operational status changed or an internal event in the collector, such as a timer triggered to referesh old enteries."; } enum delete { description "Collector has deleted an entry from its local cache."; } } description "Type of event reported by the collector."; } typedef telemetry-session-protocol-type { type identityref { base session-protocol; } description "Notification protocol used to deliver the notification to the data collection."; } container message { config false; description "Telemetry message used in Data Mesh"; leaf timestamp { type yang:date-and-time; mandatory true; description "Timestamp when the data collection collected the payload from the network element or an update or delete event is triggered."; } leaf session-protocol { type telemetry-session-protocol-type; mandatory true; description "Session protocol used to collect the payload of this message from the network"; } container network-node-manifest { description "Address of network element from which the payload is collected."; uses p-mf:platform-details; } container data-collection-manifest { description "Address of the telemetry data collection."; uses p-mf:platform-details; } container telemetry-message-metadata { description "Extensible message and protocol specific metadata"; leaf event-time { type yang:date-and-time; description "NETCONF eventTime. Redefined in here since NETCONF header is XML not YANG."; } } container data-collection-metadata { description "Metadata added by data collection."; leaf remote-address { type inet:host; mandatory true; description "Network node IP address."; } leaf remote-port { type inet:port-number; description "Network node transport port number."; } leaf local-address { type inet:host; description "Data collection IP address."; } leaf local-port { type inet:port-number; description "Data collection transport port number."; } list labels { key "name"; description "Arbiterary labels assinged by the data collection."; leaf name { type string { length "1..max"; } description "Label name."; } choice value { mandatory true; description "label value"; choice string-choice { description "String value"; leaf string-value { type string; description "String value"; } } choice anydata-choice { description "YANG anydata value"; anydata anydata-values { description "anydata yang"; } } } } } anydata payload { description "Message or notification received from network element."; } } } ]]>

Thomas Graf "; description "Augments the ietf-telemetry-message with YANG Push specific fields. 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 (RFC 2119) (RFC 8174) when, and only when, they appear in all capitals, as shown here. Copyright (c) 2025 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; see the RFC itself for full legal notices."; revision 2025-04-17 { description "Initial revision."; reference "RFC XXXX"; } augment "/tm:message/tm:telemetry-message-metadata" { description "Augments telemetry-message-metadata with YANG-Push specific metadata"; container yang-push-subscription { config false; description "YANG-Push specific metadata"; leaf id { type sn:subscription-id; description "This references the affected subscription."; } choice filter-spec { description "The content filter specification for this request."; anydata subtree-filter { description "Event stream evaluation criteria or the parameter identifies the port of the target datastore encoded in the syntax of a subtree filter as defined in RFC 6241, Section 6."; reference "RFC 6241: Network Configuration Protocol (NETCONF), Section 6."; } leaf xpath-filter { type yang:xpath1.0; description "Event stream evaluation criteria or porting of the target datastore encoded in the syntax of an XPath 1.0 expression"; reference "XML Path Language (XPath) Version 1.0 (https://www.w3.org/TR/1999/REC-xpath-19991116) RFC 7950: The YANG 1.1 Data Modeling Language, Section 10"; } } choice target { description "Identifies the source of information against which a subscription is being applied as well as specifics on the subset of information desired from that source."; case stream { leaf stream { type string; description "Indicates the event stream to be considered for this subscription."; } } case datastore { leaf datastore { type identityref { base ds:datastore; } description "Datastore from which to retrieve data."; } } } leaf transport { type sn:transport; description "For a configured subscription, this leaf specifies the transport used to deliver messages destined for all receivers of that subscription."; } leaf encoding { type sn:encoding; description "The type of encoding for notification messages. For a dynamic subscription, if not included as part of an 'establish-subscription' RPC, the encoding will be populated with the encoding used by that RPC. For a configured subscription, if not explicitly configured, the encoding will be the default encoding for an underlying transport."; } leaf purpose { type string; description "Open text allowing a configuring entity to embed the originator or other specifics of this subscription."; } choice update-trigger { description "Defines necessary conditions for sending an event record to the subscriber."; case periodic { container periodic { presence "indicates a periodic subscription"; description "The publisher is requested to notify periodically the current values of the datastore as defined by the selection filter."; leaf period { type yp:centiseconds; description "Duration of time which should occur between periodic push updates, in one hundredths of a second."; } leaf anchor-time { type yang:date-and-time; description "Designates a timestamp before or after which a series of periodic push updates are determined. The next update will take place at a whole multiple interval from the anchor time. For example, for an anchor time is set for the top of a particular minute and a period interval of a minute, updates will be sent at the top of every minute this subscription is active."; } } } case on-change { container on-change { presence "indicates an on-change subscription"; description "The publisher is requested to notify changes in values in the datastore subset as defined by a selection filter."; leaf dampening-period { type yp:centiseconds; default "0"; description "Specifies the minimum interval between the assembly of successive update records for a single receiver of a subscription. Whenever subscribed objects change, and a dampening period interval (which may be zero) has elapsed since the previous update record creation for a receiver, then any subscribed objects and properties which have changed since the previous update record will have their current values marshalled and placed into a new update record."; } leaf sync-on-start { type boolean; default "true"; description "When this object is set to false, it restricts an on-change subscription from sending push-update notifications. When false, pushing a full selection per the terms of the selection filter MUST NOT be done for this subscription. Only updates about changes, i.e. only push-change-update notifications are sent. When true (default behavior), in order to facilitate a receiver's synchronization, a full update is sent when the subscription starts using a push-update notification. After that, push-change-update notifications are exclusively sent unless the publisher chooses to resync the subscription via a new push-update notification."; } } } } list module-version { key "module-name"; config false; description "List of yang-push-module-version grouping. The revision is not configurable."; leaf module-name { type yang:yang-identifier; config false; description "This references the YANG module name."; } leaf revision { type rev:revision-date; config false; description "This references the YANG module revision of the sent notification message."; } leaf revision-label { type ysver:version; description "This references the YANG module semantic version of the sent notification message."; } } leaf yang-library-content-id { type string; config false; description "Contains the YANG library content identifier RFC 8525 information."; } } } } ]]>