IPPM G. Fioccola Internet-Draft T. Zhou Intended status: Standards Track Huawei Expires: 13 December 2026 Y. Zhu W. Zhang China Telecom K. Zhu Huawei Technologies 11 June 2026 On-Path Telemetry YANG Data Model draft-ietf-ippm-on-path-telemetry-yang-03 Abstract This document proposes a YANG data model for monitoring On-Path network performance information to be published in YANG notifications. The Alternate-Marking Method and In-situ Operations, Administration, and Maintenance (IOAM) are the On-Path hybrid measurement methods considered in this document. 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." This Internet-Draft will expire on 13 December 2026. Copyright Notice Copyright (c) 2026 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 Fioccola, et al. Expires 13 December 2026 [Page 1] Internet-Draft yang-on-path-telemetry June 2026 and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.2. Conventions . . . . . . . . . . . . . . . . . . . . . . . 3 2. Use Case . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. On-Path Telemetry Tree Diagram . . . . . . . . . . . . . . . 4 4. On-Path Telemetry Data . . . . . . . . . . . . . . . . . . . 5 5. On-Path Telemetry YANG Data Model . . . . . . . . . . . . . . 7 6. Operational Considerations . . . . . . . . . . . . . . . . . 22 7. Security Considerations . . . . . . . . . . . . . . . . . . . 22 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 23 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 23 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 24 11.1. Normative References . . . . . . . . . . . . . . . . . . 24 11.2. Informative References . . . . . . . . . . . . . . . . . 26 Appendix A. Example . . . . . . . . . . . . . . . . . . . . . . 27 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 28 1. Introduction Alternate-Marking Method [RFC9341] [RFC9342] (AltMark) is a technique used to perform packet loss, delay, and jitter measurements on in- flight packets. In-situ Operations, Administration, and Maintenance (IOAM) is a method to produce operational and telemetry information that may be exported using the in-band or out-of-band method. The data types and data formats for IOAM data records have been defined in [RFC9197] [RFC9326]. This document defines a YANG data model for monitoring On-Path telemetry information of Alternate Marking Method and IOAM. It provides YANG data models with performance monitoring parameters that can be subscribed to for monitoring and telemetry via YANG-Push specified in [RFC8639], [RFC8640] and [RFC8641]. This document uses the existing mechanisms of [RFC9341], [RFC9342], [RFC9197], [RFC9326] to monitor the performance of the network and connectivity services. Section 3 includes the tree diagram, while Section 5 includes the data model. Also, an example is reported in Appendix A. Fioccola, et al. Expires 13 December 2026 [Page 2] Internet-Draft yang-on-path-telemetry June 2026 1.1. 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 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 1.2. Conventions The following terms are defined in [RFC7950] and are used in this specification: * augment * data model * data node The terminology for describing YANG data models is found in [RFC7950]. 2. Use Case Some applications may use the subscription model specified in [RFC8641] to subscribe to the On-Path telemetry network performance data. For example, Network Telemetry [RFC9232] updates may be subscribed to YANG-Push on-change notifications [RFC8641] for state changes. YANG-Push periodic notifications [RFC8641] can be subscribed to obtain real-time performance data. There is a need for real-time traffic monitoring of the network to optimize the network performance. The next figure shows an example of a high-level workflow for dynamic network control based on traffic monitoring that could use the mechanism described in this document. +---------------------------------------------------+ | Orchestrator/Controller | +---------------------------------------------------+ | /|\ | /|\ Monitor | | Monitor | | Request | | Result Possible | | | | Optimization | | Optimization \|/ | \|/ | Result +---------------------------------------------------+ | Network | +---------------------------------------------------+ Fioccola, et al. Expires 13 December 2026 [Page 3] Internet-Draft yang-on-path-telemetry June 2026 Figure 1: Workflow for dynamic network control based on traffic monitoring The Controller sends a Monitor Request and receive Monitor Result. Because of this Closed-Loop approach, the controller can take Optimization actions, that can be related to forwarding path modification or performance measurements variation ([I-D.ietf-ippm-alt-mark-yang]), as also described in [RFC9342] with regard to the flexible and adaptive performance measurements. 3. On-Path Telemetry Tree Diagram Tree diagrams used in this document follow the notation defined in [RFC8340]. The On-Path Telemetry model is organized as shown in the following figure. This model complements the AltMark model in [I-D.ietf-ippm-alt-mark-yang] and the IOAM model in [RFC9617]. module: on-path-telemetry +--ro on-path-telemetry-data +--ro on-path-telemetry-info | +--ro timestamp-type? +--ro available-interface* [if-name] +--ro if-name if:interface-ref +--ro filter | +--ro filter-type? telemetry-filter-type | +--ro ace-name? -> /acl:acls/acl/aces/ace/name +--rw direction flow-direction +--ro protocol-type? telemetry-protocol-type +--ro profiles +--rw altmark-profile* [altmark-profile-name] | +--ro altmark-profile-name string | +--ro flow-mon-id? uint32 | +--ro measurement-period-number? uint64 | +--ro altmark-loss-measurement? | | +--ro loss-flag bits | | +--ro in-traffic-pkts? yang:counter64 | | +--ro out-traffic-pkts? yang:counter64 | | +--ro in-traffic-bytes? uint64 | | +--ro out-traffic-bytes? uint64 | +--ro altmark-delay-measurement? | +--ro delay-flag bits | +--ro in-pkts-timestamps? | | +--ro in-pkt-timestamp? yang:date-and-time | | +--ro in-pkt-seq-num? yang:counter32 | +--ro out-pkts-timestamps? Fioccola, et al. Expires 13 December 2026 [Page 4] Internet-Draft yang-on-path-telemetry June 2026 | +--ro out-pkt-timestamp? yang:date-and-time | +--ro out-pkt-seq-num? yang:counter32 +--ro path-delay-profile* [path-delay-profile-name] | +--ro path-delay-profile-name string | +--ro path-delay-mean uint32 | +--ro path-delay-min uint32 | +--ro path-delay-max uint32 | +--ro path-delay-sum uint64 +--rw ioam-profile* [ioam-profile-name] +--ro ioam-profile-name string +--ro ioam-incremental-tracing? | +--ro incremental-tracing* ioam-trace-data +--ro ioam-preallocated-tracing? | +--ro preallocated-tracing* ioam-trace-data +--ro ioam-direct-export? | +--ro direct-export* ioam-trace-data +--ro ioam-proof-of-transit? | +--ro proof-of-transit* ioam-pot-data +--ro ioam-edge-to-edge? +--ro edge-to-edge* ioam-e2e-data 4. On-Path Telemetry Data The "on-path-telemetry-data" contains detailed information for the AltMark telemetry data and IOAM telemetry data. The information includes: * available-interface: indicates the list of interface where the On- Path Telemetry is applied. The "available-interface" contains the detailed information for each interface. The information includes: * if-name: is the interface name * filter: is used to identify the monitored flow * direction: is used to identify the direction of the flow * protocol-type: is used to indicate the protocol where the On-path telemetry is applied * profiles: is the list of the telemetry profiles. The "altmark-profile" contains the detailed information for the AltMark profile. The information includes: Fioccola, et al. Expires 13 December 2026 [Page 5] Internet-Draft yang-on-path-telemetry June 2026 * altmark-profile-name: is the unique identifier for each profile * flow-mon-id: is used to identify the monitored flow and to correlate the exported data of the same flow from multiple nodes and from multiple packets. It is defined in [RFC9343] for IPv6, in [RFC9947] for SRH and in [RFC9714] for MPLS. Note that it corresponds to the altmarkFlowMonID parameter defined in [I-D.ietf-opsawg-ipfix-alt-mark]. * measurement-period-number: indicates the period number and it is defined in [I-D.ietf-ippm-alt-mark-deployment]. Note that it corresponds to the altmarkPeriodNumber parameter defined in [I-D.ietf-opsawg-ipfix-alt-mark]. * altmark-loss-measurement: indicates loss counters. * altmark-delay-measurement: indicates packet timestamps. The "altmark-loss-measurement" contains: * loss-flag: indicates the loss flag. It is defined in [RFC9343] for IPv6, in [RFC9947] for SRH and in [RFC9714] for MPLS. Note that it corresponds to the altmarkLossFlag parameter defined in [I-D.ietf-opsawg-ipfix-alt-mark]. * in-traffic-pkts: indicates the inbound packets of the period. * out-traffic-pkts: indicates the outbound packets of the period. * in-traffic-bytes: indicates the inbound bytes of the period. * out-traffic-bytes: indicates the outbound bytes of the period. The "altmark-delay-measurement" contains: * delay-flag: indicates the delay flag. It is defined in [RFC9343] for IPv6, in [RFC9947] for SRH and in [RFC9714] for MPLS. Note that it corresponds to the altmarkDelayFlag parameter defined in [I-D.ietf-opsawg-ipfix-alt-mark]. * pkts-timestamps: indicates the list of packet timestamps for delay measurement in the period (pkt-timestamp) and the corresponding sequence numbers (pkt-seq-num). The "path-delay" is introduced in [RFC9951] and contains: * path-delay-mean: indicates the mean path delay between the encapsulation/marking node and the local node. Fioccola, et al. Expires 13 December 2026 [Page 6] Internet-Draft yang-on-path-telemetry June 2026 * path-delay-min: indicates the lowest path delay between the encapsulation/marking node and the local node. * path-delay-max: indicates the highest path delay between the encapsulation/marking node and the local node. * path-delay-sum: indicates the sum of the path delay between the encapsulation/marking node and the local node. The "ioam-profile" contains the information for the IOAM profile. The information includes: * The "ioam-incremental-tracing" contains: * - incremental-tracing: indicates the list of incremental tracing data. * The "ioam-preallocated-tracing" contains: * - preallocated-tracing: indicates the list of preallocated tracing data. * The "ioam-direct-export" contains: * - direct-export: indicates the list of direct export data. * The "ioam-proof-of-transit" contains: * - proof-of-transit: indicates the list of proof of transit data. * The "ioam-edge-to-edge" contains: * - edge-to-edge: indicates the list of edge to edge data. 5. On-Path Telemetry YANG Data Model file "ietf-on-path-telemetry@2026-06-11.yang" module ietf-on-path-telemetry { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-on-path-telemetry"; prefix "on-path-telemetry"; import ietf-access-control-list { prefix acl; reference "RFC 8519: YANG Data Model for Network Access Control Lists (ACLs)"; } Fioccola, et al. Expires 13 December 2026 [Page 7] Internet-Draft yang-on-path-telemetry June 2026 import ietf-interfaces { prefix if; reference "RFC 8343: A YANG Data Model for Interface Management"; } import ietf-yang-types { prefix yang; reference "Section 3 of RFC 6991"; } 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"; } import ietf-ioam { prefix ioam; reference "RFC 9617"; } import ietf-altmark { prefix altmark; reference "draft-ietf-ippm-alt-mark-yang"; } organization "IETF IPPM (IP Performance Metrics) Working Group"; contact "WG Web: WG List: Author: giuseppe.fioccola@huawei.com Author: zhoutianran@huawei.com Author: zhuyq8@chinatelecom.cn Author: zhangwq@chinatelecom.cn Author: zhukeyi@huawei.com"; description "This YANG module specifies a vendor-independent data model for On-Path Telemetry. Fioccola, et al. Expires 13 December 2026 [Page 8] Internet-Draft yang-on-path-telemetry June 2026 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) 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 2026-06-11 { description "First revision."; reference "RFC XXXX: A YANG Data Model for On-path Telemetry"; } /* * FEATURES */ feature altmark { description "This feature indicated that the Alternate-Marking Method is supported."; reference "RFC 9341: Alternate-Marking Method; RFC 9342: Clustered Alternate-Marking Method RFC 9343: IPv6 Application of the Alternate-Marking Method RFC 9714: Application of the Alternate Marking Method to the MPLS Label Stack RFC 9947: Application of the Alternate Marking Method to the Segment Routing Header"; } feature pathdelay { description "This feature indicated that the Path Delay is supported."; reference Fioccola, et al. Expires 13 December 2026 [Page 9] Internet-Draft yang-on-path-telemetry June 2026 "RFC 9951: Export of Delay Performance Metrics in IPFIX"; } feature ioam { description "This feature indicated that the Alternate-Marking Method is supported."; reference "RFC 9197: Data Fields for In-situ OAM"; } feature incremental-trace { description "This feature indicated that the incremental tracing option is supported."; reference "RFC 9197: Data Fields for In-situ OAM"; } feature preallocated-trace { description "This feature indicated that the preallocated tracing option is supported."; reference "RFC 9197: Data Fields for In-situ OAM"; } feature direct-export { description "This feature indicated that the direct export option is supported."; reference "RFC 9326: In-situ OAM Direct Exporting"; } feature proof-of-transit { description "This feature indicated that the proof of transit option is supported"; reference "RFC 9197: Data Fields for In-situ OAM"; } feature edge-to-edge { description "This feature indicated that the edge-to-edge option is supported."; reference "RFC 9197: Data Fields for In-situ OAM"; } /* * IDENTITIES Fioccola, et al. Expires 13 December 2026 [Page 10] Internet-Draft yang-on-path-telemetry June 2026 */ identity filter { description "Base identity to represent a filter. A filter is used to specify the flow to which the On-Path Telemetry method is applied."; } identity acl-filter { base filter; description "Apply ACL rules to specify the flow."; } identity protocol { description "Base identity to represent the protocol. It's used to indicate the protocol for the application of the On-Path Telemetry method."; } identity ipv6 { base protocol; description "The On-Path Telemetry method is applied to IPv6 protocol."; reference "RFC 9343: IPv6 Application of the Alternate-Marking Method, RFC 9486: In-situ OAM IPv6 Options"; } identity srh { base protocol; description "The On-Path Telemetry method is applied to SRH."; reference "RFC 9947: Application of the Alternate Marking Method to the Segment Routing Header"; } identity mpls { base protocol; description "The On-Path Telemetry method is applied to MPLS."; reference "RFC 9714: Application of the Alternate Marking Method to the MPLS Label Stack"; } Fioccola, et al. Expires 13 December 2026 [Page 11] Internet-Draft yang-on-path-telemetry June 2026 identity nsh { base protocol; description "The described IOAM data is embedded in NSH."; reference "RFC 9452: Network Service Header (NSH) Encapsulation for In-situ OAM (IOAM) Data"; } /* * TYPE DEFINITIONS */ typedef telemetry-filter-type { type identityref { base filter; } description "It specifies a known type of filter."; } typedef telemetry-protocol-type { type identityref { base protocol; } description "It specifies a known type of carrier protocol for the On-path Telemetry data."; } typedef flow-direction { type enumeration { enum "ingress" { value 1; description "Ingress of an AltMark flow."; } enum "transit" { value 2; description "Transit of an AltMark flow."; } enum "egress" { value 3; description "Egress of an AltMark flow."; } } Fioccola, et al. Expires 13 December 2026 [Page 12] Internet-Draft yang-on-path-telemetry June 2026 description "Flow direction."; } typedef ioam-trace-data { type identityref { base ioam:trace-type; } description "It specifies the trace data."; } typedef ioam-pot-data { type identityref { base ioam:pot-type; } description "It specifies the pot data."; } typedef ioam-e2e-data { type identityref { base ioam:e2e-type; } description "It specifies the edge-to-edge data."; } /* * GROUP DEFINITIONS */ grouping telemetry-filter { description "A grouping for On-path Telemetry filter definition"; leaf filter-type { type telemetry-filter-type; description "filter type"; } leaf ace-name { when "derived-from-or-self(../filter-type, 'on-path-telemetry:acl-filter')"; type leafref { path "/acl:acls/acl:acl/acl:aces/acl:ace/acl:name"; } description Fioccola, et al. Expires 13 December 2026 [Page 13] Internet-Draft yang-on-path-telemetry June 2026 "The Access Control Entry name is used to refer to an ACL specification."; } } grouping telemetry-dir-prot { description "A grouping for On-path Telemetry information."; leaf direction { type flow-direction; description "Specify the flow direction."; } leaf protocol-type { type telemetry-protocol-type; description "This item is used to indicate the carrier protocol where the On-path Telemetry is applied."; } } grouping altmark-telemetry { description "A grouping for On-path Telemetry profile."; leaf flow-mon-id { type altmark:flow-id; description "It specifies the 20-bit FlowMonID, as defined in RFC 9343 and RFC 9714. Note that it corresponds to the altmarkFlowMonID parameter defined in draft-ietf-opsawg-ipfix-alt-mark."; } leaf measurement-period-number { type uint64; description "It specifies the On-path Telemetry period number."; } } grouping loss-counters { description "The set of counters for RFC 9341 and RFC 9342 loss calculation."; Fioccola, et al. Expires 13 December 2026 [Page 14] Internet-Draft yang-on-path-telemetry June 2026 leaf loss-flag { type bits { bit l-flag { position 0; description "It indicates the loss-flag value"; } } description "The loss-flag value is defined in RFC 9343 and RFC 9714. Note that it corresponds to the altmarkLossFlag parameter defined in draft-ietf-opsawg-ipfix-alt-mark."; } leaf in-traffic-pkts { type yang:counter64; description "Total inbound packets of the period according to RFC 9341 and RFC9342"; } leaf out-traffic-pkts { type yang:counter64; description "Total outbound packets of the period according to RFC 9341 and RFC9342"; } leaf in-traffic-bytes { type uint64; description "Total inbound bytes of the period according to RFC 9341 and RFC9342"; } leaf out-traffic-bytes { type uint64; description "Total outbound bytes of the period according to RFC 9341 and RFC9342"; } } grouping delay-timestamps { description "It indicates the set of timestamps for RFC 9341 and RFC 9342 delay calculation."; Fioccola, et al. Expires 13 December 2026 [Page 15] Internet-Draft yang-on-path-telemetry June 2026 leaf delay-flag { type bits { bit d-flag { position 0; description "It indicates the delay-flag value."; } } description "The delay-flag value is defined in RFC 9343 and RFC 9714. Note that it corresponds to the altmarkDelayFlag parameter defined in draft-ietf-opsawg-ipfix-alt-mark."; } container in-pkts-timestamps { description "The list of timestamps of the period according to RFC 9341 and RFC9342"; leaf in-pkt-timestamp { type yang:date-and-time; description "To specify the timestamp of the delay packet for delay measurements"; } leaf in-pkt-seq-num { type yang:counter32; description "To specify the sequence number of the delay packet for delay measurements"; } } container out-pkts-timestamps { description "The list of timestamps of the period according to RFC 9341 and RFC9342"; leaf out-pkt-timestamp { type yang:date-and-time; description "To specify the timestamp of the delay packet for delay measurements"; } leaf out-pkt-seq-num { type yang:counter32; Fioccola, et al. Expires 13 December 2026 [Page 16] Internet-Draft yang-on-path-telemetry June 2026 description "To specify the sequence number of the delay packet for delay measurements"; } } } grouping path-delay-metrics { description "It indicates the path delay measurements."; leaf path-delay-mean { type uint32; description "mean path delay as per RFC 9951"; } leaf path-delay-min { type uint32; description "min path delay as per RFC 9951"; } leaf path-delay-max { type uint32; description "max path delay as per RFC 9951"; } leaf path-delay-sum { type uint64; description "sum of the path delay as per RFC 9951"; } } grouping ioam-incremental-tracing-data-list { description "A grouping for incremental tracing data."; leaf-list incremental-tracing { type ioam-trace-data; description "This object indicates the incremental tracing data."; } } grouping ioam-preallocated-tracing-data-list { description Fioccola, et al. Expires 13 December 2026 [Page 17] Internet-Draft yang-on-path-telemetry June 2026 "A grouping for the list of pre-allocated tracing data."; leaf-list preallocated-tracing { type ioam-trace-data; description "This object indicates the preallocated tracing data."; } } grouping ioam-direct-export-tracing-data-list { description "A grouping for the list of direct export data."; leaf-list direct-export { type ioam-trace-data; description "This object indicates the direct export data."; } } grouping ioam-proof-of-transit-data-list { description "A grouping for the list of proof of transit data."; leaf-list proof-of-transit { type ioam-pot-data; description "This object indicates the proof of transit data."; } } grouping ioam-edge-to-edge-data-list { description "A grouping for the list of edge-to-edge data."; leaf-list edge-to-edge { type ioam-e2e-data; description "This object indicates the edge to edge data."; } } /* * DATA NODES */ container on-path-telemetry-data { config false; Fioccola, et al. Expires 13 December 2026 [Page 18] Internet-Draft yang-on-path-telemetry June 2026 description "On-path Telemetry top level container"; container on-path-telemetry-info { config false; description "Describes information such as units or timestamp format that assists monitoring systems in the interpretation of the on-path-telemetry data."; leaf timestamp-type { type identityref { base lime:timestamp-type; } description "Type of timestamp, such as Truncated PTP or NTP."; } } list available-interface { key "if-name"; description "It contains the list of the interfaces activated for Telemetry"; leaf if-name { type if:interface-ref; description "This is a reference to the Interface name."; } container filter { uses telemetry-filter; description "The filter which is used to indicate the flow where the On-path Telemetry is applied."; } uses telemetry-dir-prot; container profiles { description "Contains On-path Telemetry profiles."; list altmark-profile { if-feature altmark; key "altmark-profile-name"; description "It describes the list of the AltMark profiles configured on the node"; leaf altmark-profile-name { Fioccola, et al. Expires 13 December 2026 [Page 19] Internet-Draft yang-on-path-telemetry June 2026 type string{ length "1..300"; } description "Unique identifier for each AltMark profile."; } uses altmark-telemetry; container altmark-loss-measurement { description "It reports the loss measurement data."; uses loss-counters; } container altmark-delay-measurement { description "It reports the delay measurement data."; uses delay-timestamps; } } list path-delay-profile { if-feature pathdelay; key "path-delay-profile-name"; description "It describes the list of the path delay profiles configured on the node"; leaf path-delay-profile-name { type string { length "1..300"; } description "Unique identifier for each path delay profile."; } uses path-delay-metrics; } list ioam-profile { if-feature ioam; key "ioam-profile-name"; description "It describes the list of the path delay profiles configured on the node"; Fioccola, et al. Expires 13 December 2026 [Page 20] Internet-Draft yang-on-path-telemetry June 2026 leaf ioam-profile-name { type string{ length "1..300"; } description "Unique identifier for each path delay profile."; } container ioam-incremental-tracing { if-feature incremental-trace; presence "Enables incremental tracing option."; description "It reports the incremental tracing option data."; uses ioam-incremental-tracing-data-list; } container ioam-preallocated-tracing { if-feature preallocated-trace; presence "Enables preallocated tracing option."; description "It reports the preallocated tracing option data."; uses ioam-preallocated-tracing-data-list; } container ioam-direct-export { if-feature direct-export; presence "Enables direct-export option."; description "It reports the direct-export option data"; uses ioam-direct-export-tracing-data-list; } container ioam-proof-of-transit { if-feature proof-of-transit; presence "Enables Proof of Transit option."; description "It reports the PoT option data."; uses ioam-proof-of-transit-data-list; } container ioam-edge-to-edge { if-feature edge-to-edge; presence "Enables edge-to-edge option."; description Fioccola, et al. Expires 13 December 2026 [Page 21] Internet-Draft yang-on-path-telemetry June 2026 "It reports the edge-to-edge option data."; uses ioam-edge-to-edge-data-list; } } } } } } 6. Operational Considerations The operational and management considerations for the Alternate Marking Method are covered in [I-D.ietf-ippm-alt-mark-deployment], Alternate Marking [RFC9341] and Multipoint Alternate Marking [RFC9342]. Further details about the method operation are specified for the different extensions: IPv6 [RFC9343], SRH [RFC9947], and MPLS [RFC9714]. 7. Security Considerations The "ietf-altmark" YANG module defines a data model that is designed to be accessed via YANG-based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. These YANG-based management protocols (1) have to use a secure transport layer (e.g., Secure Shell (SSH) [RFC4252], TLS [RFC8446], and QUIC [RFC9000]) and (2) have to use mutual authentication. The Network Configuration Access Control Model (NACM) [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 but they are only readable. However, these data nodes may be considered sensitive or vulnerable in some network environments. These are the subtrees and data nodes and their sensitivity/vulnerability: * /on-path-telemetry-data/available-interface Fioccola, et al. Expires 13 December 2026 [Page 22] Internet-Draft yang-on-path-telemetry June 2026 The entries in the container above include the AltMark, path delay and IOAM profile telemetry data which can be considered sensitive or vulnerable in some network environments. It is important to control read access (e.g., via get, get-config, or notification) to the readable data nodes. The top level administrative configurations related to the AltMark and IOAM functionalities are already reported in [I-D.ietf-ippm-alt-mark-yang] and [RFC9617]. Unexpected changes to those items could lead to the AltMark and IOAM function disruption and/ or misbehavior of the AltMark. IOAM [RFC9197], Alternate Marking [RFC9341] and Multipoint Alternate Marking [RFC9342] analyze different security concerns and related solutions. These aspects are valid and applicable also to this document. In particular the fundamental security requirement is that Alternate Marking MUST only be applied in a specific limited domain, as also mentioned in [RFC8799]. 8. IANA Considerations IANA is requested to register the following URI in the "ns" registry within the IETF XML Registry [RFC3688]: URI: urn:ietf:params:xml:ns:yang:ietf-on-path-telemetry Registrant Contact: The IESG XML: N/A; the requested URI is an XML namespace. IANA is requested to register the following YANG module in the "YANG Module Names" registry [RFC6020] within the "YANG Parameters" registry group: Name: ietf-on-path-telemetry Maintained by IANA? N Namespace: urn:ietf:params:xml:ns:yang:ietf-on-path-telemetry Prefix: on-path-telemetry Reference: RFC XXXX 9. Acknowledgements The authors would like to thank Martin Bjorklund, Alex Huang Feng, Benoit Claise for the precious comments and suggestions. 10. Contributors Xiaoming He China Telecom Email: hexm4@chinatelecom.cn Fioccola, et al. Expires 13 December 2026 [Page 23] Internet-Draft yang-on-path-telemetry June 2026 11. References 11.1. Normative References [I-D.ietf-ippm-alt-mark-yang] Graf, T., Wang, M., Fioccola, G., Zhou, T., and X. Min, "A YANG Data Model for the Alternate Marking Method", Work in Progress, Internet-Draft, draft-ietf-ippm-alt-mark-yang- 02, 2 January 2026, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [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, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8639] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard, E., and A. Tripathy, "Subscription to YANG Notifications", RFC 8639, DOI 10.17487/RFC8639, September 2019, . Fioccola, et al. Expires 13 December 2026 [Page 24] Internet-Draft yang-on-path-telemetry June 2026 [RFC8640] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard, E., and A. Tripathy, "Dynamic Subscription to YANG Events and Datastores over NETCONF", RFC 8640, DOI 10.17487/RFC8640, September 2019, . [RFC8641] Clemm, A. and E. Voit, "Subscription to YANG Notifications for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641, September 2019, . [RFC9197] Brockners, F., Ed., Bhandari, S., Ed., and T. Mizrahi, Ed., "Data Fields for In Situ Operations, Administration, and Maintenance (IOAM)", RFC 9197, DOI 10.17487/RFC9197, May 2022, . [RFC9326] Song, H., Gafni, B., Brockners, F., Bhandari, S., and T. Mizrahi, "In Situ Operations, Administration, and Maintenance (IOAM) Direct Exporting", RFC 9326, DOI 10.17487/RFC9326, November 2022, . [RFC9341] Fioccola, G., Ed., Cociglio, M., Mirsky, G., Mizrahi, T., and T. Zhou, "Alternate-Marking Method", RFC 9341, DOI 10.17487/RFC9341, December 2022, . [RFC9342] Fioccola, G., Ed., Cociglio, M., Sapio, A., Sisto, R., and T. Zhou, "Clustered Alternate-Marking Method", RFC 9342, DOI 10.17487/RFC9342, December 2022, . [RFC9343] Fioccola, G., Zhou, T., Cociglio, M., Qin, F., and R. Pang, "IPv6 Application of the Alternate-Marking Method", RFC 9343, DOI 10.17487/RFC9343, December 2022, . [RFC9617] Zhou, T., Ed., Guichard, J., Brockners, F., and S. Raghavan, "A YANG Data Model for In Situ Operations, Administration, and Maintenance (IOAM)", RFC 9617, DOI 10.17487/RFC9617, August 2024, . [RFC9714] Cheng, W., Ed., Min, X., Ed., Zhou, T., Dai, J., and Y. Peleg, "Encapsulation for MPLS Performance Measurement with the Alternate-Marking Method", RFC 9714, DOI 10.17487/RFC9714, February 2025, . Fioccola, et al. Expires 13 December 2026 [Page 25] Internet-Draft yang-on-path-telemetry June 2026 11.2. Informative References [I-D.ietf-ippm-alt-mark-deployment] Fioccola, G., Zhu, K., Graf, T., Zhang, L., and M. Nilo, "Alternate Marking Deployment Framework", Work in Progress, Internet-Draft, draft-ietf-ippm-alt-mark- deployment-05, 25 February 2026, . [I-D.ietf-opsawg-ipfix-alt-mark] Graf, T., Fioccola, G., Zhou, T., and Y. Zhu, "IP Flow Information Export (IPFIX) Alternate-Marking Information Elements", Work in Progress, Internet-Draft, draft-ietf- opsawg-ipfix-alt-mark-05, 27 February 2026, . [RFC4252] Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH) Authentication Protocol", RFC 4252, DOI 10.17487/RFC4252, January 2006, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC8799] Carpenter, B. and B. Liu, "Limited Domains and Internet Protocols", RFC 8799, DOI 10.17487/RFC8799, July 2020, . [RFC9000] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based Multiplexed and Secure Transport", RFC 9000, DOI 10.17487/RFC9000, May 2021, . [RFC9232] Song, H., Qin, F., Martinez-Julia, P., Ciavaglia, L., and A. Wang, "Network Telemetry Framework", RFC 9232, DOI 10.17487/RFC9232, May 2022, . Fioccola, et al. Expires 13 December 2026 [Page 26] Internet-Draft yang-on-path-telemetry June 2026 [RFC9947] Fioccola, G., Zhou, T., Mishra, G., Wang, X., Zhang, G., and M. Cociglio, "Application of the Alternate-Marking Method to the Segment Routing Header", RFC 9947, DOI 10.17487/RFC9947, March 2026, . [RFC9951] Graf, T., Claise, B., and A. Huang-Feng, "Export of Delay Performance Metrics in IP Flow Information Export (IPFIX)", RFC 9951, DOI 10.17487/RFC9951, April 2026, . Appendix A. Example An example of the way for a client to subscribe to the telemetry information is reported in the following figure. The telemetry parameters that the client is interested are Alternate-Marking, path delay and IOAM. Fioccola, et al. Expires 13 December 2026 [Page 27] Internet-Draft yang-on-path-telemetry June 2026 10 encode-xml Authors' Addresses Giuseppe Fioccola Huawei Viale Martesana, 12 20055 Vimodrone (Milan) Italy Email: giuseppe.fioccola@huawei.com Fioccola, et al. Expires 13 December 2026 [Page 28] Internet-Draft yang-on-path-telemetry June 2026 Tianran Zhou Huawei 156 Beiqing Rd. Beijing 100095 China Email: zhoutianran@huawei.com Yongqing Zhu China Telecom Guangzhou China Email: zhuyq8@chinatelecom.cn Wenqiang Zhang China Telecom Beijing China Email: zhangwq@chinatelecom.cn Keyi Zhu Huawei Technologies Email: zhukeyi@huawei.com Fioccola, et al. Expires 13 December 2026 [Page 29]