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draft-tgraf-netconf-notif-sequencing-05.xml
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<?xml version="1.0" encoding="US-ASCII"?>
<?rfc toc="yes"?>
<?rfc tocompact="yes"?>
<?rfc tocdepth="2"?>
<?rfc tocindent="yes"?>
<?rfc symrefs="yes"?>
<?rfc sortrefs="yes"?>
<?rfc comments="yes"?>
<?rfc inline="yes"?>
<?rfc compact="yes"?>
<?rfc subcompact="no"?>
<rfc category="std" consensus="true"
docName="draft-tgraf-netconf-notif-sequencing-05" ipr="trust200902"
submissionType="IETF">
<front>
<title abbrev="YANG Notifications Sequencing">Support of Hostname and
Sequencing in YANG Notifications</title>
<author fullname="Thomas Graf" initials="T" surname="Graf">
<organization>Swisscom</organization>
<address>
<postal>
<street>Binzring 17</street>
<city>Zurich</city>
<code>8045</code>
<country>Switzerland</country>
</postal>
<email>[email protected]</email>
</address>
</author>
<author fullname="Jean Quilbeuf" initials="J" surname="Quilbeuf">
<organization>Huawei</organization>
<address>
<email>[email protected]</email>
</address>
</author>
<author fullname="Alex Huang Feng" initials="A." surname="Huang Feng">
<organization>INSA-Lyon</organization>
<address>
<postal>
<street/>
<city>Lyon</city>
<region/>
<code/>
<country>France</country>
</postal>
<phone/>
<facsimile/>
<email>[email protected]</email>
<uri/>
</address>
</author>
<date day="30" month="June" year="2024"/>
<abstract>
<t>This document specifies a new YANG module that augments the NETCONF
Event Notification header to support the hostname and sequence number to
identify from which network node and at which time the message was
published. This allows the collector to recognize loss, delay and
reordering between the publisher and the downstream system storing the
messages.</t>
</abstract>
</front>
<middle>
<section anchor="Introduction" title="Introduction">
<t>NETCONF Event Notifications <xref target="RFC5277"/> and YANG-Push
<xref target="RFC8641"/> allow NETCONF <xref target="RFC6241"/> servers
and YANG-Push publishers to send notifications to a data collection. In
the metadata of the event notification header, only the eventTime is
present indicating at which time the notification message was published.
For YANG-Push notifications, the subscription ID is added to the
"push-update" and "push-change-update" notification messages allowing
the YANG-Push receiver to map and recognize which Xpath or subtree is
bound to the subscription.</t>
<t>When the NETCONF event notification message is forwarded from the
receiver to another system, such as a messaging system or a time series
database, the transport context is lost since it is not part of the
NETCONF event notification message metadata. Therefore, the downstream
system is unable to associate the message to the publishing process (the
exporting router), nor able to detect message loss or reordering.</t>
<t>To correlate network data among different Network Telemetry planes as
described in <xref section="3.1" target="RFC9232"/> or among different
YANG-Push subscription types as defined in <xref section="3.1"
target="RFC8641"/>, a reference to the node streaming the data is
needed. This is essential for understanding the timely relationship
among these different planes and YANG-Push subscription types.</t>
<t>Today, network operators work around this impediment by preserving
the transport source IP address and sequence numbers of the publishing
process. However, this implies encoding this information in the NETCONF
event notification message which impacts the semantic readability of the
message in the downstream system.</t>
<t>On top of that, the transport source IP address might not represent
the management IP address by which the YANG-Push publisher should be
known. In other terms, the source-host <xref target="RFC6470"/>, which
is the "Address of the remote host for the session" might not be the
management IP address.</t>
<t>To overcome these issues, this document proposes extending the YANG
notification header with a sysName, the node's fully-qualified domain
name, and a sequence number as described in <xref target="RFC9187"/>.
This allows the downstream system to not only be able to identify from
which network node, subscription, and time the message was published but
also, the order of the published messages.</t>
</section>
<section anchor="Streaming-Update"
title="Extend the YANG Notification Header">
<t>NETCONF Event Notifications <xref target="RFC5277"/> and YANG-Push
<xref target="RFC8641"/> uses the same notification header that is
described in <xref section="2.2.1" target="RFC5277"/>. <xref
target="I-D.ahuang-netconf-notif-yang"/> defines how these notifications
should be encoded in JSON and CBOR.</t>
<t>Besides the eventTime described in <xref section="2.2.1"
target="RFC5277"/> the following metadata objects are part of a
notification message.</t>
<dl>
<dt>sysName:</dt>
<dd>Describes the node's fully-qualified domain name according to the
'sysName' object definition in <xref target="RFC1213"/> from where the
message was published from. This value is usually configured on the
node by the administrator to uniquely identify the node in the
network.</dd>
</dl>
<dl>
<dt>sequenceNumber:</dt>
<dd>Generates a unique sequence number for each published message by
the publisher process. The number counts up at every published
notification message as described in <xref target="RFC9187"/>.</dd>
</dl>
<section title="Extension for NETCONF Event Notifications">
<t>The Notification of NETCONF Event Notifications <xref
target="RFC5277"/> uses a XML structure that is defined in <xref
section="2.2.1" target="RFC5277"/>. <xref target="RFC5277"/> also
defines the capability
"urn:ietf:params:netconf:capability:notification:1.0" allowing a
NETCONF client to know that the NETCONF server supports sending
notifications.</t>
<section title="Notification header">
<t>An implementation supporting this document extends the
notification defined in <xref section="2.2.1" target="RFC5277"/>
adding a sysName and a sequenceNumber. Two more child nodes within
the "notification" container are expected, representing the sysName
and the sequenceNumber.</t>
<t>An example showing this extension in XML is provided in <xref
target="netconf_notification_message_example_xml_fig"/>:</t>
<figure anchor="netconf_notification_message_example_xml_fig"
title="NETCONF Event Notification message">
<artwork><![CDATA[ <notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0"> <eventTime>2007-07-08T00:10:00Z</eventTime> <sysName xmlns="urn:ietf:params:xml:ns:yang:ietf-notification-sequencing"> example-router </sysName> <sequenceNumber xmlns="urn:ietf:params:xml:ns:yang:ietf-notification-sequencing"> 187653 </sequenceNumber> <event xmlns="http://example.com/event/1.0"> <eventClass>state</eventClass> <reportingEntity> <card>Ethernet0</card> </reportingEntity> <operState>enabled</operState> </event> </notification> ]]></artwork>
</figure>
</section>
<section title="Capability exchange">
<t>This document also adds a new capability to NETCONF so that the
NETCONF server can notify the support of the sysName and
sequenceNumber to the NETCONF client.</t>
<t>When the NETCONF server supports this document, the following
capability is advertised:</t>
<artwork align="left"><![CDATA[ urn:ietf:params:netconf:capability:notification-sysname-sequence:1.0 ]]></artwork>
<t>The capability identifier is requested to IANA in <xref
target="iana"/>.</t>
<t>In the capability exchange between the NETCONF client and server,
the server will announce this capability along with the supported
capabilities by the server as shown in the example in <xref
target="capab_exchange"/>.</t>
<figure anchor="capab_exchange"
title="Example of a capability exchange.">
<artwork><![CDATA[ <hello xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"> <capabilities> <capability> urn:ietf:params:xml:ns:netconf:base:1.0 </capability> <capability> urn:ietf:params:netconf:capability:startup:1.0 </capability> <capability> urn:ietf:params:netconf:capability:notification:1.0 </capability> <capability> urn:ietf:params:netconf:capability:notification-sysname-sequence:1.0 </capability> </capabilities> <session-id>4</session-id> </hello> ]]></artwork>
</figure>
</section>
</section>
<section title="Extension for YANG-Push">
<t>YANG-Push <xref target="RFC8641"/> uses the same structure defined
in <xref target="RFC5277"/>. <xref target="RFC5277"/> defines the
structure using XML encoding. For other YANG encodings, <xref
target="I-D.ahuang-netconf-notif-yang"/> describes how notifications
should be encoded in JSON and CBOR.</t>
<section title="YANG-Push Notification header">
<t>An implementation supporting this document extends the
notification defined in <xref section="4"
target="I-D.ahuang-netconf-notif-yang"/> adding a sysName and a
sequenceNumber. Two more child nodes within the "notification" root
container are expected, representing the sysName and the
sequenceNumber.</t>
<t><xref target="notification_message_example_xml_fig"/> provides an
example of a "push-update" notification with the sysName and
sequenceNumber. This examples is encoded in XML <xref
target="W3C.REC-xml-20081126"/>.</t>
<figure anchor="notification_message_example_xml_fig"
title="YANG-Push Notification example encoded in XML">
<sourcecode type="xml"><notification
xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
<eventTime>2023-02-04T16:30:11.22Z</eventTime>
<sysName
xmlns="urn:ietf:params:xml:ns:yang:ietf-notification-sequencing">
example-router </sysName> <sequenceNumber
xmlns="urn:ietf:params:xml:ns:yang:ietf-notification-sequencing">
187653 </sequenceNumber> <push-update
xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-push">
<id>1011</id> <datastore-contents>
<interfaces
xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
<interface> <name>eth0</name>
<oper-status>up</oper-status> </interface>
</interfaces> </datastore-contents>
</push-update> </notification></sourcecode>
</figure>
<t>When the notifcation is encoded using JSON <xref
target="RFC7951"/>, the sysName and the sequenceNumber are encoded
at root container. An example is shown in <xref
target="yang_push_json"/>.</t>
<figure anchor="yang_push_json"
title="YANG-Push Notification example encoded in JSON">
<sourcecode type="json">{ "ietf-notification:notification": {
"eventTime": "2023-02-10T08:00:11.22Z",
"ietf-notification-sequencing:sysName":"example-router",
"ietf-notification-sequencing:sequenceNumber": 187653,
"ietf-yang-push:push-update": { "id": 1011, "datastore-contents":
{ "ietf-interfaces:interfaces": [ { "interface": { "name": "eth0",
"oper-status": "up" } } ] } } } }</sourcecode>
</figure>
<t>When the notification is encoded in CBOR <xref
target="RFC9254"/>, the sysName and the sequenceNumber are encoded
at root container. An example is shown in <xref
target="yang_push_cbor"/> using CBOR diagnostic notation from <xref
section="3.1" target="RFC9254"/>.</t>
<figure anchor="yang_push_cbor"
title="YANG-Push Notification example in CBOR diagnostic notation.">
<sourcecode type="cbor-diag">{ "ietf-notification:notification": {
"eventTime": "2023-02-10T08:00:11.22Z",
"ietf-notification-sequencing:sysName":"example-router",
"ietf-notification-sequencing:sequenceNumber": 187653,
"ietf-yang-push:push-update": { "id": 1011, "datastore-contents":
{ "ietf-interfaces:interfaces": [ { "interface": { "name": "eth0",
"oper-status": "up" } } ] } } } }</sourcecode>
</figure>
</section>
<section title="YANG-Push capabilities">
<t>YANG-related system capabilites can be discovered by subscribing
to the datastore defined in <xref target="RFC9196"/>. This document
augments the "ietf-notification-capabilities" defined in <xref
section="5" target="RFC9196"/> so that the YANG-Push receiver can
learn the capabilities defined in this documents throught the
datastore.</t>
<t>The definition of this YANG augmentation is specified in <xref
target="yang-model"/>.</t>
</section>
</section>
</section>
<section anchor="yang-model" title="YANG Module for Event Notifications">
<section anchor="yang-tree" title="YANG Tree Diagram">
<t>This "ietf-notification-sequencing" YANG module augments the
"ietf-notification" YANG module specified in Section 5 of <xref
target="I-D.ahuang-netconf-notif-yang"/> adding the sysName and the
sequenceNumber leaves and augments "ietf-notification-capabilities"
defined in <xref target="RFC9196"/> to add a system level
capability.</t>
<t>
<figure>
<artwork align="left"><![CDATA[ module: ietf-notification-sequencing augment /sysc:system-capabilities/notc:subscription-capabilities: +--ro sysname-sequence-supported? notification-support {sysname-sequence}? augment-structure /inotif:notification: +-- sysName inet:host +-- sequenceNumber yang:counter32 ]]></artwork>
</figure>
</t>
</section>
<section anchor="yang-full-tree" title="Full Tree View">
<t>The following is the YANG tree diagram <xref target="RFC8340"/> for
the "ietf-notification" structure:</t>
<figure>
<artwork align="left"><![CDATA[ module: ietf-notification structure notification: +-- eventTime yang:date-and-time +-- inotifseq:sysName inet:host +-- inotifseq:sequenceNumber yang:counter32 ]]></artwork>
</figure>
<t>The following YANG tree diagram <xref target="RFC8340"/> is the
full tree of the "ietf-notification-capabilities" YANG model:</t>
<figure>
<artwork align="left"><![CDATA[ module: ietf-system-capabilities +--ro system-capabilities +--ro datastore-capabilities* [datastore] | +--ro datastore | | -> /yanglib:yang-library/datastore/name | +--ro per-node-capabilities* [] | +--ro (node-selection)? | | +--:(node-selector) | | +--ro node-selector? | | nacm:node-instance-identifier | +--ro notc:subscription-capabilities | +--ro notc:max-nodes-per-update? uint32 | +--ro notc:periodic-notifications-supported? | | notification-support | +--ro (notc:update-period)? | | +--:(notc:minimum-update-period) | | | +--ro notc:minimum-update-period? uint32 | | +--:(notc:supported-update-period) | | +--ro notc:supported-update-period* uint32 | +--ro notc:on-change-supported? | | notification-support {yp:on-change}? | +--ro notc:minimum-dampening-period? uint32 | | {yp:on-change}? | +--ro notc:supported-excluded-change-type* union | {yp:on-change}? +--ro notc:subscription-capabilities +--ro notc:max-nodes-per-update? uint32 +--ro notc:periodic-notifications-supported? | notification-support +--ro (notc:update-period)? | +--:(notc:minimum-update-period) | | +--ro notc:minimum-update-period? uint32 | +--:(notc:supported-update-period) | +--ro notc:supported-update-period* uint32 +--ro notc:on-change-supported? | notification-support {yp:on-change}? +--ro notc:minimum-dampening-period? uint32 | {yp:on-change}? +--ro notc:supported-excluded-change-type* union | {yp:on-change}? +--ro inotifseq:sysname-sequence-supported? notification-support {sysname-sequence}? ]]></artwork>
</figure>
</section>
<section anchor="yang-module" title="YANG Module">
<t>The "ietf-notification-sequencing" augments the "ietf-notification"
and "ietf-notification-capabilities" YANG modules.</t>
<figure>
<artwork align="left"><![CDATA[ <CODE BEGINS> file "[email protected]" module ietf-notification-sequencing { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-notification-sequencing"; prefix inotifseq; import ietf-inet-types { prefix inet; reference "RFC 6991: Common YANG Data Types"; } import ietf-yang-types { prefix yang; reference "RFC 6991: Common YANG Data Types"; } import ietf-notification { prefix inotif; reference "draft-ahuang-netconf-notif-yang: NETCONF Event Notification YANG"; } import ietf-system-capabilities { prefix sysc; reference "RFC 9196: YANG Modules Describing Capabilities for Systems and Datastore Update Notifications"; } import ietf-notification-capabilities { prefix notc; reference "RFC 9196: YANG Modules Describing Capabilities for Systems and Datastore Update Notifications"; } import ietf-yang-structure-ext { prefix sx; reference "RFC 8791: YANG Data Structure Extensions"; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: <http:/tools.ietf.org/wg/netconf/> WG List: <mailto:[email protected]> Authors: Thomas Graf <mailto:[email protected]> Jean Quilbeuf <mailto:[email protected]> Alex Huang Feng <mailto:[email protected]>"; description "Defines NETCONF Event Notification structure with the sysName and the sequenceNumber. Copyright (c) 2024 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 2023-06-30 { description "First revision"; reference "RFC XXXX: YANG Notifications Sequencing"; } feature sysname-sequence { description "This feature indicates that sysName and sequenceNumber are supported in notifications."; } typedef notification-support { type bits { bit config-changes { description "The publisher is capable of sending notifications for 'config true' nodes for the relevant scope and subscription type."; } bit state-changes { description "The publisher is capable of sending notifications for 'config false' nodes for the relevant scope and subscription type."; } } description "Redefition of the type 'notification-support' from 'ietf-notification-capabilities' module to be reusable in other YANG modules. Type for defining whether 'on-change' or 'periodic' notifications are supported for all data nodes, 'config false' data nodes, 'config true' data nodes, or no data nodes. The bits config-changes or state-changes have no effect when they are set for a datastore or for a set of nodes that does not contain nodes with the indicated config value. In those cases, the effect is the same as if no support was declared. One example of this is indicating support for state-changes for a candidate datastore that has no effect."; reference "RFC XXXX: YANG Notifications Sequencing RFC 9196: YANG Modules Describing Capabilities for Systems and Datastore Update Notifications"; } sx:augment-structure "/inotif:notification" { leaf sysName { type inet:host; mandatory true; description "Fully-qualified domain name of the node according to [RFC1213]. This value is usually configured on the node by the administrator to uniquely identify the node in the network."; } leaf sequenceNumber { type yang:counter32; mandatory true; description "Generates a unique sequence number for each published message by the publisher process. The number counts up at every published notification message as described [RFC9187]."; } } augment "/sysc:system-capabilities/notc:subscription-capabilities" { description "Add system level capabilities"; leaf sysname-sequence-supported { if-feature "sysname-sequence"; type notification-support; description "Specifies whether the publisher supports exporting a sysName and a sequenceNumber in notifications."; reference "RFC XXXX: YANG Notifications Sequencing"; } } } <CODE ENDS>]]></artwork>
</figure>
</section>
</section>
<section anchor="Implementation" title="Implementation Status">
<t>Note to the RFC-Editor: Please remove this section before
publishing.</t>
<section anchor="SIXWIND" title="6WIND VSR">
<t>6WIND implemented this document for a YANG-Push publisher on <xref
target="I-D.ietf-netconf-udp-notif"> UDP-based Transport for
Configured Subscriptions</xref> in their VSR platform.</t>
</section>
</section>
<section anchor="Security" title="Security Considerations">
<t>The security considerations for the NETCONF Event notifications are
described in <xref target="RFC5277"/>. This documents adds no additional
security considerations.</t>
</section>
<section anchor="iana" title="IANA Considerations">
<section title="IETF XML Registry">
<t>This document registers the following URIs in the "IETF XML
Registry" <xref target="RFC3688"/>:</t>
<t>
<figure>
<artwork align="left"><![CDATA[ URI: urn:ietf:params:xml:ns:yang:ietf-notification-sequencing Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace.]]></artwork>
</figure>
</t>
</section>
<section title="YANG Module Name">
<t>This document registers the following YANG modules in the "YANG
Module Names" registry <xref target="RFC6020"/>:</t>
<figure>
<artwork align="left"><![CDATA[ name: ietf-notification-sequencing namespace: urn:ietf:params:xml:ns:yang:ietf-notification-sequencing prefix: inotifseq reference: RFC XXXX]]></artwork>
</figure>
</section>
<section title="NETCONF Capability URNs Registry">
<t>This document registers the following NETCONF capability in the
"Network Configuration Protocol (NETCONF) Capability URNs"
registry:</t>
<figure>
<artwork align="left"><![CDATA[ Capability: :notification-sysname-sequence:1.0 Capability Identifier: urn:ietf:params:netconf:capability:notification-sysname-sequence:1.0 Reference: RFC XXXX]]></artwork>
</figure>
</section>
</section>
<section anchor="Operational" title="Operational Considerations">
<section anchor="operational_sysname_correlation"
title="SysName Correlation">
<t>In order to allow data correlation among BGP Monitoring Protocol
(BMP) <xref target="RFC7854"/> and YANG-Push, the same hostname value
should be used as described in <xref section="4.4" target="RFC7854"/>
for the information TLV in the init BMP message type.</t>
</section>
</section>
<section anchor="Acknowledgements" title="Acknowledgements">
<t>The authors would like to thank Rob Wilton, Nick Corran, Pierre
Francois, Benoit Claise, Ahmed Elhassany and Ignacio Dominguez
Martinez-Casanueva for their review and valuable comments.</t>
</section>
</middle>
<back>
<references title="Normative References">
<?rfc include='https://xml.resource.org/public/rfc/bibxml/reference.RFC.1213.xml'?>
<?rfc include='https://xml.resource.org/public/rfc/bibxml/reference.RFC.3688.xml'?>
<?rfc include='https://xml.resource.org/public/rfc/bibxml/reference.RFC.5277.xml'?>
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<?rfc include='https://xml.resource.org/public/rfc/bibxml/reference.RFC.6241.xml'?>
<?rfc include='https://xml.resource.org/public/rfc/bibxml/reference.RFC.7951.xml'?>
<?rfc include='https://xml.resource.org/public/rfc/bibxml/reference.RFC.8340.xml'?>
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<?rfc include='https://xml.resource.org/public/rfc/bibxml/reference.RFC.9196.xml'?>
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<?rfc include='https://xml.resource.org/public/rfc/bibxml/reference.RFC.9254.xml'?>
<?rfc include='https://xml.resource.org/public/rfc/bibxml-ids/reference.I-D.ahuang-netconf-notif-yang.xml'?>
<reference anchor="W3C.REC-xml-20081126"
derivedAnchor="W3C.REC-xml-20081126" quoteTitle="true"
target="https://www.w3.org/TR/2008/REC-xml-20081126">
<front>
<title>Extensible Markup Language (XML) 1.0 (Fifth Edition)</title>
<author fullname="Tim Bray" initials="T." surname="Bray">
<organization showOnFrontPage="true"/>
</author>
<author fullname="Jean Paoli" initials="J." surname="Paoli">
<organization showOnFrontPage="true"/>
</author>
<author fullname="Michael Sperberg-McQueen" initials="M."
surname="Sperberg-McQueen">
<organization showOnFrontPage="true"/>
</author>
<author fullname="Eve Maler" initials="E." surname="Maler">
<organization showOnFrontPage="true"/>
</author>
<author fullname="Francois Yergeau" initials="F." surname="Yergeau">
<organization showOnFrontPage="true"/>
</author>
<date month="November" year="2008"/>
</front>
<refcontent>World Wide Web Consortium Recommendation
REC-xml-20081126</refcontent>
</reference>
</references>
<references title="Informative References">
<?rfc include='https://xml.resource.org/public/rfc/bibxml/reference.RFC.6470.xml'?>
<?rfc include='https://xml.resource.org/public/rfc/bibxml/reference.RFC.7854.xml'?>
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<?rfc include="https://xml.resource.org/public/rfc/bibxml-ids/reference.I-D.ietf-netconf-udp-notif.xml"?>
</references>
</back>
</rfc>