NETCONF Working Group Q. Wu Internet-Draft Q. Ma Intended status: Standards Track Huawei Expires: January 13, 2022 P. Liu China Mobile W. Wang China Telecom July 12, 2021 Telemetry Data Export capability draft-tao-netconf-data-export-capabilities-05 Abstract This document proposes a YANG module for telemetry data export capabilities which augments system Capabilities model and provides additional telemetry data export attributes associated with system capabilities for transport specific Notification. This YANG module can be used by the client to learn capability information from the server at run-time or implementation- time, per the YANG Instance Data File Format. 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 January 13, 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 Wu, et al. Expires January 13, 2022 [Page 1] Internet-Draft Data Export Capability July 2021 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 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. Data Export capability . . . . . . . . . . . . . . . . . . . 3 2.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 4 3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 4.1. Updates to the IETF XML Registry . . . . . . . . . . . . 10 4.2. Updates to the YANG Module Names Registry . . . . . . . . 10 5. Security Considerations . . . . . . . . . . . . . . . . . . . 10 6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 11 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 7.1. Normative References . . . . . . . . . . . . . . . . . . 12 7.2. Informative References . . . . . . . . . . . . . . . . . 13 Appendix A. Usage Example of interaction with UDP Notif and HTTP Notif for Configured Subscription . . . . . . . . . 14 Appendix B. Usage Example of interaction with Adaptive Subscription . . . . . . . . . . . . . . . . . . . . 15 Appendix C. Changes between Revisions . . . . . . . . . . . . . 18 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 1. Introduction Notification capabilities model defined in [I-D.netconf-notification- capabilities] allows a client to discover a set of capabilities supported by the server (e.g., basic system capabilities and YANG- Push related capabilities) both at implementation-time and run-time. These capabilities allow the client adjust its behavior to take advantage of the features exposed by the device. However the client and the server may still support various different transport specific parameters (e.g., transport protocol, encoding format, encryption). As described in section 3.1 of [RFC8641], a simple negotiation (i.e., inserting hints into error responses to a failed RPC request) between subscribers and publishers for subscription parameters increases the likelihood of success for subsequent RPC requests, but not guaranteed, which may cause unexpected failure or additional message exchange between client and server. Wu, et al. Expires January 13, 2022 [Page 2] Internet-Draft Data Export Capability July 2021 This document defines a corresponding solution that is built on top of [I-D.netconf-notification-capabilities]. Supplementing that work are YANG data model augmentations for transport specific notification. The module can be used by the client to discover capability information from the server at run-time or implementation- time, per the YANG Instance Data File Format. 1.1. 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. 2. Data Export capability The YANG module ietf-notification-capabilities defined in [I- D.netconf-notification-capabilities] specify the following server capabilities related to YANG Push: o A set of capabilities related to the amount of notifications the server can send out o Specification of which data nodes support on-change notifications. o Capability values can be specified on server level, datastore level or on specific data nodes (and their contained sub-tree) of a specific datastore. Capability values on a smaller, more specific part of the server's data always override more generic values. o On-change capability is not specified on a server level as different datastores usually have different on-change capabilities. On a datastore level on-change capability for configuration and state data can be specified separately. These server capabilities are transport independent, session level capabilities. They can be provided either at the implementation time or reported at the run time. This document augments system Capabilities model and provides additional data export attributes associated with system capabilities: o Specification of transport protocol the client can use to establish a transport connection; Wu, et al. Expires January 13, 2022 [Page 3] Internet-Draft Data Export Capability July 2021 o Specification of the encoding selection used (e.g., XML or JSON, Binary) for Data Modeled with YANG; o Specification of secure transport mechanisms that are needed by the client to communicate with the server; o Specification of the type of data compression algorithm (e.g., lossless data compression) the client can use for file compression and decompression o Specification of the notification message encapsulation type, either one notification per message or multiple notifications per message. o Specification of the update trigger type such as adaptive interval trigger, timer event based trigger, count threshold trigger, redundant suppression. 2.1. Tree Diagram The following tree diagram [RFC8340] provides an overview of the data model. module: ietf-data-export-capabilities augment /sysc:system-capabilities: +--ro data-export-capabilities* [] +--ro transport-protocol? identityref +--ro encoding-format*? identityref +--ro security-protocol? identityref +--ro compression-mode*? identityref +--ro message-bundling-support? empty augment /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-node-capabilities: +--ro data-export-capabilities +--ro adaptive-interval-support? empty +--ro timer-event-support? empty +--ro counter-threshold-support? empty +--ro suppress-redundant? empty 3. YANG Module file "ietf-data-export-capabilities.yang" module ietf-data-export-capabilities { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-data-export-capabilities"; prefix dec; import ietf-system-capabilities { Wu, et al. Expires January 13, 2022 [Page 4] Internet-Draft Data Export Capability July 2021 prefix sysc; } import ietf-notification-capabilities { prefix inc; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: Editor: Qin Wu Editor: Qiufang Ma Editor: Peng Liu Editor: Wei Wang "; description "This module defines an extension to System Capability and YANG Push Notification Capabilities model and provides additional data export attributes for transport specific notification. Copyright (c) 2019 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 2020-07-03 { description "Initial revision."; reference "RFC XXXX: Telemetry Data Export capability"; } identity transport-protocol { description "Base identity for transport protocol type."; } identity tcp { base transport-protocol; description "Identity for tcp as transport protocol."; Wu, et al. Expires January 13, 2022 [Page 5] Internet-Draft Data Export Capability July 2021 } identity udp-notif { base transport-protocol; description "Identity for udp notif as transport protocol."; reference "draft-ietf-netconf-udp-notif:UDP-based Transport for Configured Subscriptions"; } identity http-notif { base transport-protocol; description "Identity for http notif as transport protocol."; reference "draft-ietf-netconf-https-notif: An HTTPS-based Transport for Configured Subscriptions"; } identity grpc { base transport-protocol; description "Identity for grpc as transport protocol."; } identity security-protocol { description "Base identity for security protocol type."; } identity tls { base security-protocol; description "Identity for tls security protocol."; } identity ssh { base security-protocol; description "Identity for ssh transport protocol."; } identity encoding-format { description "Base identity for encoding format type."; } Wu, et al. Expires January 13, 2022 [Page 6] Internet-Draft Data Export Capability July 2021 identity xml { base encoding-format; description "Identity for xml encoding format."; } identity json { base encoding-format; description "Identity for json encoding format."; } identity binary { base encoding-format; description "Identity for binary encoding format."; } identity gpb { base binary; description "Identity for gpb encoding format."; } identity cbor { base binary; description "Identity for cbor encoding format."; } identity compression-mode { description "Base identity for compression mode."; } identity gzip { base compression-mode; description "Identity for gzip compression mode."; } identity deflate { base compression-mode; description "Identity for deflate compression mode."; } identity subscription-mode { Wu, et al. Expires January 13, 2022 [Page 7] Internet-Draft Data Export Capability July 2021 description "Base identity for subscription mode."; } identity periodic { base subscription-mode; description "Identity for periodic subscription mode."; } identity on-change { base subscription-mode; description "Identity for on change subscription mode."; } identity event { base subscription-mode; description "Identity for event based subscription mode."; } typedef centiseconds { type uint32; description "A period of time, measured in units of 0.01 seconds."; } augment "/sysc:system-capabilities" { description "Add system level capability."; list data-export-capabilities { description "Capabilities related to telemetry data export capabilities negotiation."; leaf transport-protocol { type identityref { base transport-protocol; } description "Type of transport protocol."; } leaf-list encoding-format { type identityref { base encoding-format; } description "Type of encoding format."; } Wu, et al. Expires January 13, 2022 [Page 8] Internet-Draft Data Export Capability July 2021 leaf security-protocol { type identityref { base security-protocol; } description "Type of secure transport."; } leaf-list compression-mode { type identityref { base compression-mode; } description "Type of compression mode."; } leaf message-bundling-support { type empty; description "Enables message bundling support."; } } } augment "/sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-node-capabilities" { description "Add datastore and node level capability."; container data-export-capabilities { description "Capabilities related to telemetry data export capability negotiation."; leaf adaptive-interval-support { type empty; description "Present if one event stream supports multiple period intervals and allows period interval switching. Absent if the event stream doesn't support period interval switching."; } leaf timer-event-support { type empty; description "Present if timer event is supported, i.e.,, schedule a specific event periodically with specified start time, duration, repeat option, repeat interval."; } leaf counter-threshold-support { type empty; description "Present if the subscription mode is counter based trigger is support (i.e., named counter crosses a specified threshold). Absent if coutner based Wu, et al. Expires January 13, 2022 [Page 9] Internet-Draft Data Export Capability July 2021 trigger mode is not supported. "; } leaf suppress-redundant { type empty; description "Suppress dupplicated data objects to be sent during each update interval."; } } } } 4. IANA Considerations 4.1. Updates to the IETF XML Registry This document registers a URI in the "IETF XML Registry" [RFC3688]. Following the format in [RFC3688], the following registration has been made: URI: urn:ietf:params:xml:ns:yang:ietf-data-export-capabilities Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. 4.2. Updates to the YANG Module Names Registry This document registers one YANG module in the "YANG Module Names" registry [RFC6020]. Following the format in [RFC6020], the following registration has been made: name: ietf-data-export-capabilities namespace: urn:ietf:params:xml:ns:yang:ietf-data-export-capabilities prefix: dec reference: RFC XXXX (RFC Ed.: replace XXX with actual RFC number and remove this note.) 5. Security Considerations The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer Wu, et al. Expires January 13, 2022 [Page 10] Internet-Draft Data Export Capability July 2021 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 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 that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive 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 /sysc:system-capabilities/dec:transport-protocol o /sysc:system-capabilities/dec:encoding-format o /sysc:system-capabilities/dec:security-protocol o /sysc:system-capabilities/dec:compression-mode o /sysc:system-capabilities/inc:subscription-capabilities/ dec:message-bundling-support 6. Contributors Wu, et al. Expires January 13, 2022 [Page 11] Internet-Draft Data Export Capability July 2021 Ran Tao Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: taoran20@huawei.com Liang Geng China Mobile 32 Xuanwumen West St, Xicheng District Beijing 10053 Email: gengliang@chinamobile.com Thomas Graf Swisscom Binzring 17 Zuerich 8045 Switzerland Email: thomas.graf@swisscom.com 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [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, . [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, . Wu, et al. Expires January 13, 2022 [Page 12] Internet-Draft Data Export Capability July 2021 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, . [RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 8407, DOI 10.17487/RFC8407, October 2018, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . 7.2. Informative References [I-D.ietf-netconf-https-notif] Jethanandani, M. and K. Watsen, "An HTTPS-based Transport for YANG Notifications", draft-ietf-netconf-https-notif-08 (work in progress), February 2021. [I-D.ietf-netconf-udp-notif] Zheng, G., Zhou, T., Graf, T., Francois, P., and P. Lucente, "UDP-based Transport for Configured Subscriptions", draft-ietf-netconf-udp-notif-01 (work in progress), November 2020. [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . Wu, et al. Expires January 13, 2022 [Page 13] Internet-Draft Data Export Capability July 2021 [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . Appendix A. Usage Example of interaction with UDP Notif and HTTP Notif for Configured Subscription The following instance-data example describes the Data Export Notification capabilities of a hypothetical "acme-router". acme-router-notification-capabilities ietf-system-capabilities@2020-03-23 ietf-notification-capabilities@2020-03-23 ietf-data-export-capabilities@2020-03-23 Server Capability Discovery http-notif json xml udp-notif binary In addition, the client could also query data export capability from the server. For example, the client sends request message to the the server to query data export capability from the server. Wu, et al. Expires January 13, 2022 [Page 14] Internet-Draft Data Export Capability July 2021 The server returns server data export capability using as follows: http-notif json udp-notif binary Appendix B. Usage Example of interaction with Adaptive Subscription The following instance-data example describes the Data Export Notification capabilities of a hypothetical "acme-router". The router implements the running, and operational datastores. Every change can be reported on-change from running, but only config = true nodes and some config = false data from operational. Interface statistics are reported only when both adaptive-interval-support and count-threshold-support are present. acme-router-notification-capabilities ietf-system-capabilities@2020-03-23 ietf-notification-capabilities@2020-03-23 ietf-data-export-capabilities@2020-03-23 Wu, et al. Expires January 13, 2022 [Page 15] Internet-Draft Data Export Capability July 2021 Defines the notification capabilities of an acme-router. The router only has running, and operational datastores. Every change can be reported on-change from running, but only config=true nodes and some config=false data from operational. Statistics are not reported based on timer based trigger and counter threshold based trigger. ds:operational /if:interfaces/if:interface/if:statistics 5 state-changes /if:interfaces/if:interface/if:statistics/if:out-octets /if:interfaces/if:interface/if:statistics/if:in-errors Wu, et al. Expires January 13, 2022 [Page 16] Internet-Draft Data Export Capability July 2021 The client configures adaptive subscription parameters on the server. The adaptive subscription configuration parameters require the server to scan all interface of specific type every 5 seconds if the value of interface in-errors is greater than 1000; If the interface in- errors value is less than 1000, switch to 60 seconds period value, and then scan all client every 60 seconds. ds:running /if:ietf-interfaces /if:interfaces/if:interface/if:statistics in-errors in-errors > 1000 1000 5 in-errors < 1000 1000 60 Wu, et al. Expires January 13, 2022 [Page 17] Internet-Draft Data Export Capability July 2021 Appendix C. Changes between Revisions v04 - v05 o Change per-node-capabilities related parameters into empty type. o Revise abstract and introduction section to only focus on capability fetching mechanism from the client to the server. o Update Usage Example of interaction with HTTP-Notif and UDP-Notif for Configured Subscription. v03 - v04 o Add interface namespace in the Adaptive Subscription usage example. o subtrees and data nodes changes in the security section. o Two compression mode related identities change. o Move message-bundling-support parameer to system capabilities level. o Add an example to discuss report reciever capability from the client per yang instance file format. o Change encoding format from leaf to leaf-list and support multiple encoding formats for the same transport specific notif. v02 - v03 o Change 'data-export-capabilities' into list type to support multiple transport protocol, encoding on the server. o Add Usage Example of interaction with UDP based Transport for Configured Subscription. o Add Thomas Graf as a contributor; o Update motivation in the introduction to clarify why this work is needed. o Support udp notif and http notif as two optional transport in the YANG data model. Wu, et al. Expires January 13, 2022 [Page 18] Internet-Draft Data Export Capability July 2021 Authors' Addresses Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: bill.wu@huawei.com Qiufang Ma Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: maqiufang1@huawei.com Peng Liu China Mobile Beiqijia Town, Changping District Beijing 10053 Email: liupengyjy@chinamobile.com Wei Wang China Telecom 32 Xuanwumen West St, Xicheng District Beijing 102209 Email: wangw36@chinatelecom.cn Wu, et al. Expires January 13, 2022 [Page 19]