< draft-ietf-netconf-yang-push-21.txt		draft-ietf-netconf-yang-push-22.txt >
	NETCONF A. Clemm		NETCONF A. Clemm
	Internet-Draft Huawei USA		Internet-Draft Huawei USA
	Intended status: Standards Track E. Voit		Intended status: Standards Track E. Voit
	Expires: August 2, 2019 Cisco Systems		Expires: August 8, 2019 Cisco Systems
	A. Gonzalez Prieto		A. Gonzalez Prieto
	Microsoft		Microsoft
	A. Tripathy		A. Tripathy
	E. Nilsen-Nygaard		E. Nilsen-Nygaard
	Cisco Systems		Cisco Systems
	A. Bierman		A. Bierman
	YumaWorks		YumaWorks
	B. Lengyel		B. Lengyel
	Ericsson		Ericsson
	January 29, 2019		February 4, 2019
	Subscription to YANG Datastores		Subscription to YANG Datastores
	draft-ietf-netconf-yang-push-21		draft-ietf-netconf-yang-push-22
	Abstract		Abstract
	Via the mechanism described in this document, subscriber applications		Via the mechanism described in this document, subscriber applications
	may request a continuous, customized stream of updates from a YANG		may request a continuous, customized stream of updates from a YANG
	datastore. Providing such visibility into updates enables new		datastore. Providing such visibility into updates enables new
	capabilities based on the remote mirroring and monitoring of		capabilities based on the remote mirroring and monitoring of
	configuration and operational state.		configuration and operational state.
	Status of This Memo		Status of This Memo
	skipping to change at page 1, line 44 ¶		skipping to change at page 1, line 44 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at https://datatracker.ietf.org/drafts/current/.		Drafts is at https://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on August 2, 2019.		This Internet-Draft will expire on August 8, 2019.
	Copyright Notice		Copyright Notice
	Copyright (c) 2019 IETF Trust and the persons identified as the		Copyright (c) 2019 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 2, line 51 ¶		skipping to change at page 2, line 51 ¶
	3.5. Data Encodings . . . . . . . . . . . . . . . . . . . . . 9		3.5. Data Encodings . . . . . . . . . . . . . . . . . . . . . 9
	3.6. Defining the Selection with a Datastore . . . . . . . . . 10		3.6. Defining the Selection with a Datastore . . . . . . . . . 10
	3.7. Streaming Updates . . . . . . . . . . . . . . . . . . . . 11		3.7. Streaming Updates . . . . . . . . . . . . . . . . . . . . 11
	3.8. Subscription Management . . . . . . . . . . . . . . . . . 13		3.8. Subscription Management . . . . . . . . . . . . . . . . . 13
	3.9. Receiver Authorization . . . . . . . . . . . . . . . . . 15		3.9. Receiver Authorization . . . . . . . . . . . . . . . . . 15
	3.10. On-Change Notifiable Datastore Nodes . . . . . . . . . . 16		3.10. On-Change Notifiable Datastore Nodes . . . . . . . . . . 16
	3.11. Other Considerations . . . . . . . . . . . . . . . . . . 17		3.11. Other Considerations . . . . . . . . . . . . . . . . . . 17
	4. A YANG Data Model for Management of Datastore Push		4. A YANG Data Model for Management of Datastore Push
	Subscriptions . . . . . . . . . . . . . . . . . . . . . . . . 18		Subscriptions . . . . . . . . . . . . . . . . . . . . . . . . 18
	4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 18		4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 18
	4.2. Subscription Configuration . . . . . . . . . . . . . . . 23		4.2. Subscription Configuration . . . . . . . . . . . . . . . 24
	4.3. YANG Notifications . . . . . . . . . . . . . . . . . . . 24		4.3. YANG Notifications . . . . . . . . . . . . . . . . . . . 25
	4.4. YANG RPCs . . . . . . . . . . . . . . . . . . . . . . . . 25		4.4. YANG RPCs . . . . . . . . . . . . . . . . . . . . . . . . 26
	5. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 30		5. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 31
	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 46		6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 48
	7. Security Considerations . . . . . . . . . . . . . . . . . . . 46		7. Security Considerations . . . . . . . . . . . . . . . . . . . 48
	8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 48		8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 49
	9. References . . . . . . . . . . . . . . . . . . . . . . . . . 48		9. References . . . . . . . . . . . . . . . . . . . . . . . . . 50
	9.1. Normative References . . . . . . . . . . . . . . . . . . 48		9.1. Normative References . . . . . . . . . . . . . . . . . . 50
	9.2. Informative References . . . . . . . . . . . . . . . . . 49		9.2. Informative References . . . . . . . . . . . . . . . . . 51
	Appendix A. Appendix A: Subscription Errors . . . . . . . . . . 50		Appendix A. Appendix A: Subscription Errors . . . . . . . . . . 51
	A.1. RPC Failures . . . . . . . . . . . . . . . . . . . . . . 50		A.1. RPC Failures . . . . . . . . . . . . . . . . . . . . . . 52
	A.2. Notifications of Failure . . . . . . . . . . . . . . . . 51		A.2. Notifications of Failure . . . . . . . . . . . . . . . . 53
	Appendix B. Changes Between Revisions . . . . . . . . . . . . . 51		Appendix B. Changes Between Revisions . . . . . . . . . . . . . 53
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 55		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 57
	1. Introduction		1. Introduction
	Traditional approaches to providing visibility into managed entities		Traditional approaches to providing visibility into managed entities
	from remote have been built on polling. With polling, data is		from remote have been built on polling. With polling, data is
	periodically requested and retrieved by a client from a server to		periodically requested and retrieved by a client from a server to
	stay up-to-date. However, there are issues associated with polling-		stay up-to-date. However, there are issues associated with polling-
	based management:		based management:
	o Polling incurs significant latency. This latency prohibits many		o Polling incurs significant latency. This latency prohibits many
	skipping to change at page 4, line 13 ¶		skipping to change at page 4, line 13 ¶
	of "Custom Subscription to Event Streams"		of "Custom Subscription to Event Streams"
	[I-D.draft-ietf-netconf-subscribed-notifications]. Supplementing		[I-D.draft-ietf-netconf-subscribed-notifications]. Supplementing
	that work are YANG data model augmentations, extended RPCs, and new		that work are YANG data model augmentations, extended RPCs, and new
	datastore specific update notifications. Transport options for		datastore specific update notifications. Transport options for
	[I-D.draft-ietf-netconf-subscribed-notifications] will work		[I-D.draft-ietf-netconf-subscribed-notifications] will work
	seamlessly with this solution.		seamlessly with this solution.
	2. Definitions and Acronyms		2. Definitions and Acronyms
			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.
	This document uses the terminology defined in [RFC7950], [RFC8341],		This document uses the terminology defined in [RFC7950], [RFC8341],
	[RFC8342], and [I-D.draft-ietf-netconf-subscribed-notifications]. In		[RFC8342], and [I-D.draft-ietf-netconf-subscribed-notifications]. In
	addition, the following terms are introduced:		addition, the following terms are introduced:
	o Datastore node: A node in the instantiated YANG data tree		o Datastore node: A node in the instantiated YANG data tree
	associated with a datastore. In this document, datastore nodes		associated with a datastore. In this document, datastore nodes
	are often also simply referred to as "objects"		are often also simply referred to as "objects"
	o Datastore node update: A data item containing the current value of		o Datastore node update: A data item containing the current value of
	a datastore node at the time the datastore node update was		a datastore node at the time the datastore node update was
	skipping to change at page 13, line 5 ¶		skipping to change at page 13, line 5 ¶
	</interfaces>		</interfaces>
	</datastore-contents>		</datastore-contents>
	</push-update>		</push-update>
	</notification>		</notification>
	Figure 1: Push example		Figure 1: Push example
	The following is an example of an on-change notification message for		The following is an example of an on-change notification message for
	the same subscription.		the same subscription.
	<notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">		<notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
	<eventTime>2017-10-25T08:22:33.44Z</eventTime>		<eventTime>2017-10-25T08:22:33.44Z</eventTime>
	<push-change-update xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-push">		<push-change-update
	<id>89</id>		xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-push">
	<datastore-changes>		<id>89</id>
	<yang-patch>		<datastore-changes>
	<patch-id>0</patch-id>		<yang-patch>
	<edit>		<patch-id>0</patch-id>
	<edit-id>edit1</edit-id>		<edit>
	<operation>replace</operation>		<edit-id>edit1</edit-id>
	<target>/ietf-interfaces:interfaces</target>		<operation>replace</operation>
	<value>		<target>/ietf-interfaces:interfaces</target>
	<interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">		<value>
	<interface>		<interfaces
	<name>eth0</name>		xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
	<oper-status>down</oper-status>		<interface>
	</interface>		<name>eth0</name>
	</interfaces>		<oper-status>down</oper-status>
	</value>		</interface>
	</edit>		</interfaces>
	</yang-patch>		</value>
	</datastore-changes>		</edit>
	</push-change-update>		</yang-patch>
	</notification>		</datastore-changes>
			</push-change-update>
			</notification>
	Figure 2: Push example for on change		Figure 2: Push example for on change
	Of note in the above example is the 'patch-id' with a value of '0'.		Of note in the above example is the 'patch-id' with a value of '0'.
	Per [RFC8072], the 'patch-id' is an arbitrary string. With YANG		Per [RFC8072], the 'patch-id' is an arbitrary string. With YANG
	Push, the publisher SHOULD put into the 'patch-id' a counter starting		Push, the publisher SHOULD put into the 'patch-id' a counter starting
	at '0' which increments with every 'push-change-update' generated for		at '0' which increments with every 'push-change-update' generated for
	a subscription. If used as a counter, this counter MUST be reset to		a subscription. If used as a counter, this counter MUST be reset to
	'0' anytime a resynchronization occurs (i.e., with the sending of a		'0' anytime a resynchronization occurs (i.e., with the sending of a
	'push-update'). Also if used as a counter, the counter MUST be reset		'push-update'). Also if used as a counter, the counter MUST be reset
	skipping to change at page 14, line 30 ¶		skipping to change at page 14, line 32 ¶
	"establish-subscription-stream-error-info" that is inserted in case		"establish-subscription-stream-error-info" that is inserted in case
	of a stream subscription.		of a stream subscription.
	Below is a tree diagram for "establish-subscription-datastore-error-		Below is a tree diagram for "establish-subscription-datastore-error-
	info". All tree diagrams used in this document follow the notation		info". All tree diagrams used in this document follow the notation
	defined in [RFC8340]		defined in [RFC8340]
	yang-data establish-subscription-datastore-error-info		yang-data establish-subscription-datastore-error-info
	+--ro establish-subscription-datastore-error-info		+--ro establish-subscription-datastore-error-info
	+--ro reason? identityref		+--ro reason? identityref
	+--ro period-hint? yang:timeticks		+--ro period-hint? centiseconds
	+--ro filter-failure-hint? string		+--ro filter-failure-hint? string
	+--ro object-count-estimate? uint32		+--ro object-count-estimate? uint32
	+--ro object-count-limit? uint32		+--ro object-count-limit? uint32
	+--ro kilobytes-estimate? uint32		+--ro kilobytes-estimate? uint32
	+--ro kilobytes-limit? uint32		+--ro kilobytes-limit? uint32
	Figure 3: Tree diagram for establish-subscription-datastore-error-		Figure 3: Tree diagram for establish-subscription-datastore-error-
	info		info
	Similarly, in the case of a rejected request for modification of a		Similarly, in the case of a rejected request for modification of a
	skipping to change at page 15, line 8 ¶		skipping to change at page 15, line 8 ¶
	info" container inserted into the RPC error response, in lieu of the		info" container inserted into the RPC error response, in lieu of the
	"modify-subscription-stream-error-info" that is inserted in case of a		"modify-subscription-stream-error-info" that is inserted in case of a
	stream subscription.		stream subscription.
	Below is a tree diagram for "modify-subscription-datastore-error-		Below is a tree diagram for "modify-subscription-datastore-error-
	info".		info".
	yang-data modify-subscription-datastore-error-info		yang-data modify-subscription-datastore-error-info
	+--ro modify-subscription-datasore-error-info		+--ro modify-subscription-datasore-error-info
	+--ro reason? identityref		+--ro reason? identityref
	+--ro period-hint? yang:timeticks		+--ro period-hint? centiseconds
	+--ro filter-failure-hint? string		+--ro filter-failure-hint? string
	+--ro object-count-estimate? uint32		+--ro object-count-estimate? uint32
	+--ro object-count-limit? uint32		+--ro object-count-limit? uint32
	+--ro kilobytes-estimate? uint32		+--ro kilobytes-estimate? uint32
	+--ro kilobytes-limit? uint32		+--ro kilobytes-limit? uint32
	Figure 4: Tree diagram for modify-subscription-datastore-error-info		Figure 4: Tree diagram for modify-subscription-datastore-error-info
	3.9. Receiver Authorization		3.9. Receiver Authorization
	skipping to change at page 18, line 23 ¶		skipping to change at page 18, line 23 ¶
	changes (one second periods will consume more resources than one hour		changes (one second periods will consume more resources than one hour
	periods), the amount of data in the datastore subtree that is being		periods), the amount of data in the datastore subtree that is being
	subscribed to, and the number and combination of other subscriptions		subscribed to, and the number and combination of other subscriptions
	that are concurrently being serviced.		that are concurrently being serviced.
	4. A YANG Data Model for Management of Datastore Push Subscriptions		4. A YANG Data Model for Management of Datastore Push Subscriptions
	4.1. Overview		4.1. Overview
	The YANG data model for datastore push subscriptions is depicted in		The YANG data model for datastore push subscriptions is depicted in
	the following figure. The tree diagram follows the notation defined		the following figures. The tree diagram that is used follows the
	in [RFC8340]. New schema objects defined here (i.e., beyond those		notation defined in [RFC8340]. New schema objects defined here
	from [I-D.draft-ietf-netconf-subscribed-notifications]) are		(i.e., beyond those from
	identified with "yp". For the reader's convenience, in order to		[I-D.draft-ietf-netconf-subscribed-notifications]) are identified
	compact the tree representation, some nodes that are defined in ietf-		with "yp". For the reader's convenience, in order to compact the
	subscribed-notifications and that are not essential to the		tree representation, some nodes that are defined in ietf-subscribed-
	understanding of the data model defined here have been removed. This		notifications and that are not essential to the understanding of the
	is indicated by "..." in the diagram where applicable.		data model defined here have been removed. This is indicated by
			"..." in the diagram where applicable.
			Because the tree diagram is quite large, its depiction is broken up
			into several figures. The first figure depicts the augmentations
			that are introduced in module ietf-yang-push to subscription
			configuration specified in module ietf-subscribed-notifications.
	module: ietf-subscribed-notifications		module: ietf-subscribed-notifications
	...		...
	+--rw filters		+--rw filters
	| ...		| ...
	| +--rw yp:selection-filter* [filter-id]		| +--rw yp:selection-filter* [filter-id]
	| +--rw yp:filter-id string		| +--rw yp:filter-id string
	| +--rw (yp:filter-spec)?		| +--rw (yp:filter-spec)?
	| +--:(yp:datastore-subtree-filter)		| +--:(yp:datastore-subtree-filter)
	| | +--rw yp:datastore-subtree-filter? <anydata>		| | +--rw yp:datastore-subtree-filter? <anydata>
	skipping to change at page 19, line 20 ¶		skipping to change at page 19, line 42 ¶
	| +--:(yp:datastore-subtree-filter)		| +--:(yp:datastore-subtree-filter)
	| | +--rw yp:datastore-subtree-filter?		| | +--rw yp:datastore-subtree-filter?
	| | <anydata> {sn:subtree}?		| | <anydata> {sn:subtree}?
	| +--:(yp:datastore-xpath-filter)		| +--:(yp:datastore-xpath-filter)
	| +--rw yp:datastore-xpath-filter?		| +--rw yp:datastore-xpath-filter?
	| yang:xpath1.0 {sn:xpath}?		| yang:xpath1.0 {sn:xpath}?
	| ...		| ...
	+--rw (yp:update-trigger)		+--rw (yp:update-trigger)
	+--:(yp:periodic)		+--:(yp:periodic)
	| +--rw yp:periodic!		| +--rw yp:periodic!
	| +--rw yp:period yang:timeticks		| +--rw yp:period centiseconds
	| +--rw yp:anchor-time? yang:date-and-time		| +--rw yp:anchor-time? yang:date-and-time
	+--:(yp:on-change) {on-change}?		+--:(yp:on-change) {on-change}?
	+--rw yp:on-change!		+--rw yp:on-change!
	+--rw yp:dampening-period? yang:timeticks		+--rw yp:dampening-period? centiseconds
	+--rw yp:sync-on-start? boolean		+--rw yp:sync-on-start? boolean
	+--rw yp:excluded-change* change-type		+--rw yp:excluded-change* change-type
			Figure 6: Model structure: subscription configuration
			The next figure depicts the augmentations of module ietf-yang-push
			made to RPCs specified in module ietf-subscribed-notifications.
			Specifically, these augmentations concern the establish-subscription
			and modify-subscription RPCs, which are augmented with parameters
			that are needed to specify datastore push subscriptions.
	rpcs:		rpcs:
	+---x establish-subscription		+---x establish-subscription
	| +---w input		| +---w input
	| | ...		| | ...
	| | +---w (target)		| | +---w (target)
	| | | +--:(stream)		| | | +--:(stream)
	| | | | ...		| | | | ...
	| | | +--:(yp:datastore)		| | | +--:(yp:datastore)
	| | | +---w yp:datastore identityref		| | | +---w yp:datastore identityref
	| | | +---w (yp:selection-filter)?		| | | +---w (yp:selection-filter)?
	skipping to change at page 20, line 5 ¶		skipping to change at page 20, line 36 ¶
	| | | +--:(yp:datastore-subtree-filter)		| | | +--:(yp:datastore-subtree-filter)
	| | | | +---w yp:datastore-subtree-filter?		| | | | +---w yp:datastore-subtree-filter?
	| | | | <anydata> {sn:subtree}?		| | | | <anydata> {sn:subtree}?
	| | | +--:(yp:datastore-xpath-filter)		| | | +--:(yp:datastore-xpath-filter)
	| | | +---w yp:datastore-xpath-filter?		| | | +---w yp:datastore-xpath-filter?
	| | | yang:xpath1.0 {sn:xpath}?		| | | yang:xpath1.0 {sn:xpath}?
	| | | ...		| | | ...
	| | +---w (yp:update-trigger)		| | +---w (yp:update-trigger)
	| | +--:(yp:periodic)		| | +--:(yp:periodic)
	| | | +---w yp:periodic!		| | | +---w yp:periodic!
	| | | +---w yp:period yang:timeticks		| | | +---w yp:period centiseconds
	| | | +---w yp:anchor-time? yang:date-and-time		| | | +---w yp:anchor-time? yang:date-and-time
	| | +--:(yp:on-change) {on-change}?		| | +--:(yp:on-change) {on-change}?
	| | +---w yp:on-change!		| | +---w yp:on-change!
	| | +---w yp:dampening-period? yang:timeticks		| | +---w yp:dampening-period? centiseconds
	| | +---w yp:sync-on-start? boolean		| | +---w yp:sync-on-start? boolean
	| | +---w yp:excluded-change* change-type		| | +---w yp:excluded-change* change-type
	| +--ro output		| +--ro output
	| +--ro id subscription-id		| +--ro id subscription-id
	| +--ro replay-start-time-revision? yang:date-and-time		| +--ro replay-start-time-revision? yang:date-and-time
	| {replay}?		| {replay}?
	+---x modify-subscription		+---x modify-subscription
	| +---w input		| +---w input
	| ...		| ...
	| +---w (target)		| +---w (target)
	skipping to change at page 20, line 21 ¶		skipping to change at page 21, line 4 ¶
	| | +---w yp:excluded-change* change-type		| | +---w yp:excluded-change* change-type
	| +--ro output		| +--ro output
	| +--ro id subscription-id		| +--ro id subscription-id
	| +--ro replay-start-time-revision? yang:date-and-time		| +--ro replay-start-time-revision? yang:date-and-time
	| {replay}?		| {replay}?
	+---x modify-subscription		+---x modify-subscription
	| +---w input		| +---w input
	| ...		| ...
	| +---w (target)		| +---w (target)
	| | ...		| | ...
	| | +--:(yp:datastore)		| | +--:(yp:datastore)
	| | +---w yp:datastore identityref		| | +---w yp:datastore identityref
	| | +---w (yp:selection-filter)?		| | +---w (yp:selection-filter)?
	| | +--:(yp:by-reference)		| | +--:(yp:by-reference)
	| | | +---w yp:selection-filter-ref		| | | +---w yp:selection-filter-ref
	| | | selection-filter-ref		| | | selection-filter-ref
	| | +--:(yp:within-subscription)		| | +--:(yp:within-subscription)
	| | +---w (yp:filter-spec)?		| | +---w (yp:filter-spec)?
	| | +--:(yp:datastore-subtree-filter)		| | +--:(yp:datastore-subtree-filter)
	| | | +---w yp:datastore-subtree-filter?		| | | +---w yp:datastore-subtree-filter?
	| | | <anydata> {sn:subtree}?		| | | <anydata> {sn:subtree}?
	| | +--:(yp:datastore-xpath-filter)		| | +--:(yp:datastore-xpath-filter)
	| | +---w yp:datastore-xpath-filter?		| | +---w yp:datastore-xpath-filter?
	| | yang:xpath1.0 {sn:xpath}?		| | yang:xpath1.0 {sn:xpath}?
	| | ...		| | ...
	| +---w (yp:update-trigger)		| +---w (yp:update-trigger)
	| +--:(yp:periodic)		| +--:(yp:periodic)
	| | +---w yp:periodic!		| | +---w yp:periodic!
	| | +---w yp:period yang:timeticks		| | +---w yp:period centiseconds
	| | +---w yp:anchor-time? yang:date-and-time		| | +---w yp:anchor-time? yang:date-and-time
	| +--:(yp:on-change) {on-change}?		| +--:(yp:on-change) {on-change}?
	| +---w yp:on-change!		| +---w yp:on-change!
	| +---w yp:dampening-period? yang:timeticks		| +---w yp:dampening-period? centiseconds
	+---x delete-subscription		+---x delete-subscription
	| ...		| ...
	+---x kill-subscription		+---x kill-subscription
	...		...
	yang-data (for placement into rpc error responses)		yang-data (for placement into rpc error responses)
	...		...
			Figure 7: Model structure: RPCs
			The next figure depicts augmentations of module ietf-yang-push to the
			notifications that are specified in module ietf-subscribed-
			notifications. The augmentations allow to include subscription
			configuration parameters that are specific to datastore push
			subscriptions as part of subscription-started and subscription-
			modified notifications.
	notifications:		notifications:
	+---n replay-completed {replay}?		+---n replay-completed {replay}?
	| ...		| ...
	+---n subscription-completed		+---n subscription-completed
	| ...		| ...
	+---n subscription-started {configured}?		+---n subscription-started {configured}?
	| | ...		| | ...
	| +--ro (target)		| +--ro (target)
	| | ...		| | ...
	| | +--:(yp:datastore)		| | +--:(yp:datastore)
	skipping to change at page 21, line 32 ¶		skipping to change at page 22, line 23 ¶
	| | +--:(yp:datastore-subtree-filter)		| | +--:(yp:datastore-subtree-filter)
	| | | +--ro yp:datastore-subtree-filter?		| | | +--ro yp:datastore-subtree-filter?
	| | | <anydata> {sn:subtree}?		| | | <anydata> {sn:subtree}?
	| | +--:(yp:datastore-xpath-filter)		| | +--:(yp:datastore-xpath-filter)
	| | +--ro yp:datastore-xpath-filter?		| | +--ro yp:datastore-xpath-filter?
	| | yang:xpath1.0 {sn:xpath}?		| | yang:xpath1.0 {sn:xpath}?
	| ...		| ...
	| +--ro (yp:update-trigger)		| +--ro (yp:update-trigger)
	| +--:(yp:periodic)		| +--:(yp:periodic)
	| | +--ro yp:periodic!		| | +--ro yp:periodic!
	| | +--ro yp:period yang:timeticks		| | +--ro yp:period centiseconds
	| | +--ro yp:anchor-time? yang:date-and-time		| | +--ro yp:anchor-time? yang:date-and-time
	| +--:(yp:on-change) {on-change}?		| +--:(yp:on-change) {on-change}?
	| +--ro yp:on-change!		| +--ro yp:on-change!
	| +--ro yp:dampening-period? yang:timeticks		| +--ro yp:dampening-period? centiseconds
	| +--ro yp:sync-on-start? boolean		| +--ro yp:sync-on-start? boolean
	| +--ro yp:excluded-change* change-type		| +--ro yp:excluded-change* change-type
	+---n subscription-resumed		+---n subscription-resumed
	| ...		| ...
	+---n subscription-modified		+---n subscription-modified
	| ...		| ...
	| +--ro (target)		| +--ro (target)
	| | | ...		| | | ...
	| | +--:(yp:datastore)		| | +--:(yp:datastore)
	| | +--ro yp:datastore identityref		| | +--ro yp:datastore identityref
	skipping to change at page 22, line 14 ¶		skipping to change at page 23, line 6 ¶
	| | +--:(yp:datastore-subtree-filter)		| | +--:(yp:datastore-subtree-filter)
	| | | +--ro yp:datastore-subtree-filter?		| | | +--ro yp:datastore-subtree-filter?
	| | | <anydata> {sn:subtree}?		| | | <anydata> {sn:subtree}?
	| | +--:(yp:datastore-xpath-filter)		| | +--:(yp:datastore-xpath-filter)
	| | +--ro yp:datastore-xpath-filter?		| | +--ro yp:datastore-xpath-filter?
	| | yang:xpath1.0 {sn:xpath}?		| | yang:xpath1.0 {sn:xpath}?
	| ...		| ...
	| +--ro (yp:update-trigger)?		| +--ro (yp:update-trigger)?
	| +--:(yp:periodic)		| +--:(yp:periodic)
	| | +--ro yp:periodic!		| | +--ro yp:periodic!
	| | +--ro yp:period yang:timeticks		| | +--ro yp:period centiseconds
	| | +--ro yp:anchor-time? yang:date-and-time		| | +--ro yp:anchor-time? yang:date-and-time
	| +--:(yp:on-change) {on-change}?		| +--:(yp:on-change) {on-change}?
	| +--ro yp:on-change!		| +--ro yp:on-change!
	| +--ro yp:dampening-period? yang:timeticks		| +--ro yp:dampening-period? centiseconds
	| +--ro yp:sync-on-start? boolean		| +--ro yp:sync-on-start? boolean
	| +--ro yp:excluded-change* change-type		| +--ro yp:excluded-change* change-type
	+---n subscription-terminated		+---n subscription-terminated
	| ...		| ...
	+---n subscription-suspended		+---n subscription-suspended
	...		...
			Figure 8: Model structure: Notifications
			The final figure in this section depicts the parts of module ietf-
			yang-push that are not simply augmentations to another module, but
			that are newly introduced.
	module: ietf-yang-push		module: ietf-yang-push
	rpcs:		rpcs:
	+---x resync-subscription {on-change}?		+---x resync-subscription {on-change}?
	+---w input		+---w input
	+---w id sn:subscription-id		+---w id sn:subscription-id
	yang-data: (for placement into rpc error responses)		yang-data: (for placement into rpc error responses)
	+-- resync-subscription-error		+-- resync-subscription-error
	| +--ro reason? identityref		| +--ro reason? identityref
	| +--ro period-hint? timeticks		| +--ro period-hint? centiseconds
	| +--ro filter-failure-hint? string		| +--ro filter-failure-hint? string
	| +--ro object-count-estimate? uint32		| +--ro object-count-estimate? uint32
	| +--ro object-count-limit? uint32		| +--ro object-count-limit? uint32
	| +--ro kilobytes-estimate? uint32		| +--ro kilobytes-estimate? uint32
	| +--ro kilobytes-limit? uint32		| +--ro kilobytes-limit? uint32
	+-- establish-subscription-error-datastore		+-- establish-subscription-error-datastore
	| +--ro reason? identityref		| +--ro reason? identityref
	| +--ro period-hint? timeticks		| +--ro period-hint? centiseconds
	| +--ro filter-failure-hint? string		| +--ro filter-failure-hint? string
	| +--ro object-count-estimate? uint32		| +--ro object-count-estimate? uint32
	| +--ro object-count-limit? uint32		| +--ro object-count-limit? uint32
	| +--ro kilobytes-estimate? uint32		| +--ro kilobytes-estimate? uint32
	| +--ro kilobytes-limit? uint32		| +--ro kilobytes-limit? uint32
	+-- modify-subscription-error-datastore		+-- modify-subscription-error-datastore
	+--ro reason? identityref		+--ro reason? identityref
	+--ro period-hint? timeticks		+--ro period-hint? centiseconds
	+--ro filter-failure-hint? string		+--ro filter-failure-hint? string
	+--ro object-count-estimate? uint32		+--ro object-count-estimate? uint32
	+--ro object-count-limit? uint32		+--ro object-count-limit? uint32
	+--ro kilobytes-estimate? uint32		+--ro kilobytes-estimate? uint32
	+--ro kilobytes-limit? uint32		+--ro kilobytes-limit? uint32
	notifications:		notifications:
	+---n push-update		+---n push-update
	| +--ro id? sn:subscription-id		| +--ro id? sn:subscription-id
	| +--ro datastore-contents? <anydata>		| +--ro datastore-contents? <anydata>
	| +--ro incomplete-update? empty		| +--ro incomplete-update? empty
	+---n push-change-update {on-change}?		+---n push-change-update {on-change}?
	+--ro id? sn:subscription-id		+--ro id? sn:subscription-id
	+--ro datastore-changes?		+--ro datastore-changes
	| +--ro yang-patch		| +--ro yang-patch
	| +--ro patch-id string		| +--ro patch-id string
	| +--ro ypatch:comment? string		| +--ro comment? string
	| +--ro ypatch:edit* [edit-id]		| +--ro edit* [edit-id]
	| +--ro ypatch:edit-id string		| +--ro edit-id string
	| +--ro ypatch:operation enumeration		| +--ro operation enumeration
	| +--ro ypatch:target target-resource-offset		| +--ro target target-resource-offset
	| +--ro ypatch:point? target-resource-offset		| +--ro point? target-resource-offset
	| +--ro ypatch:where? enumeration		| +--ro where? enumeration
	| +--ro ypatch:value?		| +--ro value? <anydata>
	+--ro incomplete-update? empty		+--ro incomplete-update? empty
	Figure 6: Model structure		Figure 9: Model structure (non-augmentation portions
	Selected components of the model are summarized below.		Selected components of the model are summarized below.
	4.2. Subscription Configuration		4.2. Subscription Configuration
	Both configured and dynamic subscriptions are represented within the		Both configured and dynamic subscriptions are represented within the
	list "subscription". New parameters extending the basic subscription		list "subscription". New parameters extending the basic subscription
	data model in [I-D.draft-ietf-netconf-subscribed-notifications]		data model in [I-D.draft-ietf-netconf-subscribed-notifications]
	include:		include:
	skipping to change at page 26, line 5 ¶		skipping to change at page 27, line 5 ¶
	YANG-Push subscriptions are established, modified, and deleted using		YANG-Push subscriptions are established, modified, and deleted using
	RPCs augmented from		RPCs augmented from
	[I-D.draft-ietf-netconf-subscribed-notifications].		[I-D.draft-ietf-netconf-subscribed-notifications].
	4.4.1. Establish-subscription RPC		4.4.1. Establish-subscription RPC
	The subscriber sends an establish-subscription RPC with the		The subscriber sends an establish-subscription RPC with the
	parameters in section 3.1. An example might look like:		parameters in section 3.1. An example might look like:
	<netconf:rpc message-id="101"		<netconf:rpc message-id="101"
	xmlns:netconf="urn:ietf:params:xml:ns:netconf:base:1.0">		xmlns:netconf="urn:ietf:params:xml:ns:netconf:base:1.0">
	<establish-subscription		<establish-subscription
	xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications"		xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications"
	xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-yang-push">		xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-yang-push">
	<yp:datastore xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">		<yp:datastore
	ds:operational		xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
	</yp:datastore>		ds:operational
	<yp:datastore-xpath-filter		</yp:datastore>
	xmlns:ex="http://example.com/sample-data/1.0">		<yp:datastore-xpath-filter
	/ex:foo		xmlns:ex="http://example.com/sample-data/1.0">
	</yp:datastore-xpath-filter>		/ex:foo
	<yp:periodic>		</yp:datastore-xpath-filter>
	<yp:period>500</yp:period>		<yp:periodic>
	</yp:periodic>		<yp:period>500</yp:period>
	</establish-subscription>		</yp:periodic>
	</netconf:rpc>		</establish-subscription>
			</netconf:rpc>
	Figure 7: Establish-subscription RPC		Figure 10: Establish-subscription RPC
	A positive response includes the "id" of the accepted subscription.		A positive response includes the "id" of the accepted subscription.
	In that case a publisher may respond:		In that case a publisher may respond:
	<rpc-reply message-id="101"		<rpc-reply message-id="101"
	xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">		xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
	<id		<id
	xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications">		xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications">
	52		52
	</id>		</id>
	</rpc-reply>		</rpc-reply>
	Figure 8: Establish-subscription positive RPC response		Figure 11: Establish-subscription positive RPC response
	A subscription can be rejected for multiple reasons, including the		A subscription can be rejected for multiple reasons, including the
	lack of authorization to establish a subscription, no capacity to		lack of authorization to establish a subscription, no capacity to
	serve the subscription at the publisher, or the inability of the		serve the subscription at the publisher, or the inability of the
	publisher to select datastore content at the requested cadence.		publisher to select datastore content at the requested cadence.
	If a request is rejected because the publisher is not able to serve		If a request is rejected because the publisher is not able to serve
	it, the publisher SHOULD include in the returned error hints which		it, the publisher SHOULD include in the returned error hints which
	help a subscriber understand subscription parameters might have been		help a subscriber understand subscription parameters might have been
	accepted for the request. These hints would be included within the		accepted for the request. These hints would be included within the
	yang-data structure "establish-subscription-error-datastore".		yang-data structure "establish-subscription-error-datastore".
	However even with these hints, there are no guarantee that subsequent		However even with these hints, there are no guarantee that subsequent
	requests will in fact be accepted.		requests will in fact be accepted.
	The specific parameters to be returned as part of the RPC error		The specific parameters to be returned as part of the RPC error
	response depend on the specific transport that is used to manage the		response depend on the specific transport that is used to manage the
	subscription. For NETCONF, those parameters are defined in		subscription. For NETCONF, those parameters are defined in
	[I-D.draft-ietf-netconf-netconf-event-notifications]. For example,		[I-D.draft-ietf-netconf-netconf-event-notifications]. For example,
	for the following NETCONF request:		for the following NETCONF request:
	<netconf:rpc message-id="101"		<rpc message-id="101"
	xmlns:netconf="urn:ietf:params:xml:ns:netconf:base:1.0">		xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
	<establish-subscription		<establish-subscription
	xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications"		xmlns=
	xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-yang-push">		"urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications"
	<yp:datastore		xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-yang-push">
	xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">		<yp:datastore
	ds:operational		xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
	</yp:datastore>		ds:operational
	<yp:datastore-xpath-filter		</yp:datastore>
	xmlns:ex="http://example.com/sample-data/1.0">		<yp:datastore-xpath-filter
	/ex:foo		xmlns:ex="http://example.com/sample-data/1.0">
	</yp:datastore-xpath-filter>		/ex:foo
	<yp:on-change>		</yp:datastore-xpath-filter>
	<yp:dampening-period>100</yp:dampening-period>		<yp:on-change>
	</yp:on-change>		<yp:dampening-period>100</yp:dampening-period>
	</establish-subscription>		</yp:on-change>
	</netconf:rpc>		</establish-subscription>
			</rpc>
	Figure 9: Establish-subscription request example 2		Figure 12: Establish-subscription request example 2
	a publisher that cannot serve on-change updates but periodic updates		a publisher that cannot serve on-change updates but periodic updates
	might return the following NETCONF response:		might return the following NETCONF response:
	<rpc-reply message-id="101"		<rpc-reply message-id="101"
	xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"		xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
	xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications">		xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications">
	<rpc-error>		<rpc-error>
	<error-type>application</error-type>		<error-type>application</error-type>
	<error-tag>operation-failed</error-tag>		<error-tag>operation-failed</error-tag>
	<error-severity>error</error-severity>		<error-severity>error</error-severity>
	<error-path>/yp:periodic/yp:period</error-path>		<error-path>/yp:periodic/yp:period</error-path>
	<error-info>		<error-info>
	<yp:establish-subscription-error-datastore>		<yp:establish-subscription-error-datastore>
	<yp:reason>yp:on-change-unsupported</yp:reason>		<yp:reason>yp:on-change-unsupported</yp:reason>
	</yp:establish-subscription-error-datastore>		</yp:establish-subscription-error-datastore>
	</error-info>		</error-info>
	</rpc-error>		</rpc-error>
	</rpc-reply>		</rpc-reply>
	Figure 10: Establish-subscription error response example 2		Figure 13: Establish-subscription error response example 2
	4.4.2. Modify-subscription RPC		4.4.2. Modify-subscription RPC
	The subscriber MAY invoke the "modify-subscription" RPC for a		The subscriber MAY invoke the "modify-subscription" RPC for a
	subscription it previously established. The subscriber will include		subscription it previously established. The subscriber will include
	newly desired values in the "modify-subscription" RPC. Parameters		newly desired values in the "modify-subscription" RPC. Parameters
	not included MUST remain unmodified. Below is an example where a		not included MUST remain unmodified. Below is an example where a
	subscriber attempts to modify the period and datastore XPath filter		subscriber attempts to modify the period and datastore XPath filter
	of a subscription using NETCONF.		of a subscription using NETCONF.
	<netconf:rpc message-id="102"		<rpc message-id="102"
	xmlns:netconf="urn:ietf:params:xml:ns:netconf:base:1.0">		xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
	<modify-subscription		<modify-subscription
	xmlns="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications"		xmlns=
	xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-yang-push">		"urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications"
	<id>1011</id>		xmlns:yp="urn:ietf:params:xml:ns:yang:ietf-yang-push">
	<yp:datastore		<id>1011</id>
	xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">		<yp:datastore
	ds:operational		xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
	</yp:datastore>		ds:operational
	<yp:datastore-xpath-filter		</yp:datastore>
	xmlns:ex="http://example.com/sample-data/1.0">		<yp:datastore-xpath-filter
	/ex:bar		xmlns:ex="http://example.com/sample-data/1.0">
	</yp:datastore-xpath-filter>		/ex:bar
	<yp:periodic>		</yp:datastore-xpath-filter>
	<yp:period>250</yp:period>		<yp:periodic>
	</yp:periodic>		<yp:period>250</yp:period>
	</modify-subscription>		</yp:periodic>
	</netconf:rpc>		</modify-subscription>
			</rpc>
	Figure 11: Modify subscription request		Figure 14: Modify subscription request
	The publisher MUST respond to the subscription modification request.		The publisher MUST respond to the subscription modification request.
	If the request is rejected, the existing subscription is left		If the request is rejected, the existing subscription is left
	unchanged, and the publisher MUST send an RPC error response. This		unchanged, and the publisher MUST send an RPC error response. This
	response might have hints encapsulated within the yang-data structure		response might have hints encapsulated within the yang-data structure
	"modify-subscription-error-datastore". A subscription MAY be		"modify-subscription-error-datastore". A subscription MAY be
	modified multiple times.		modified multiple times.
	The specific parameters to be returned in as part of the RPC error		The specific parameters to be returned in as part of the RPC error
	response depend on the specific transport that is used to manage the		response depend on the specific transport that is used to manage the
	skipping to change at page 29, line 19 ¶		skipping to change at page 30, line 19 ¶
	"establish-subscription" RPC, a subscriber can send a "delete-		"establish-subscription" RPC, a subscriber can send a "delete-
	subscription" RPC, which takes as only input the subscription's "id".		subscription" RPC, which takes as only input the subscription's "id".
	This RPC is unmodified from		This RPC is unmodified from
	[I-D.draft-ietf-netconf-subscribed-notifications].		[I-D.draft-ietf-netconf-subscribed-notifications].
	4.4.4. Resync-subscription RPC		4.4.4. Resync-subscription RPC
	This RPC is supported only for on-change subscriptions previously		This RPC is supported only for on-change subscriptions previously
	established using an "establish-subscription" RPC. For example:		established using an "establish-subscription" RPC. For example:
	<netconf:rpc message-id="103"		<rpc message-id="103"
	xmlns:netconf="urn:ietf:params:xml:ns:netconf:base:1.0">		xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
	<resync-subscription		<resync-subscription
	xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-push"		xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-push"
	xmlns:sn="urn:ietf:params:xml:ns:yang:ietf-subscribed-notifications">		<id>1011</id>
	<id>1011</id>		</resync-subscription>
	</resync-subscription>		</netconf:rpc>
	</netconf:rpc>
	Resync subscription		Figure 15: Resync subscription
	On receipt, a publisher must either accept the request and quickly		On receipt, a publisher must either accept the request and quickly
	follow with a "push-update", or send an appropriate error within an		follow with a "push-update", or send an appropriate error within an
	rpc error response. Within an error response, the publisher MAY		rpc error response. Within an error response, the publisher MAY
	include supplemental information about the reasons within the yang-		include supplemental information about the reasons within the yang-
	data structure "resync-subscription-error".		data structure "resync-subscription-error".
	4.4.5. YANG Module Synchronization		4.4.5. YANG Module Synchronization
	To make subscription requests, the subscriber needs to know the YANG		To make subscription requests, the subscriber needs to know the YANG
	skipping to change at page 30, line 7 ¶		skipping to change at page 31, line 7 ¶
	run-time (if supported by the publisher implementation). For this		run-time (if supported by the publisher implementation). For this
	purpose, the YANG library provides a simple "yang-library-change"		purpose, the YANG library provides a simple "yang-library-change"
	notification that informs the subscriber that the library has		notification that informs the subscriber that the library has
	changed. In this case, a subscription may need to be updated to take		changed. In this case, a subscription may need to be updated to take
	the updates into account. The receiver may also need to be informed		the updates into account. The receiver may also need to be informed
	of module changes in order to process updates regarding datastore		of module changes in order to process updates regarding datastore
	nodes from changed modules correctly.		nodes from changed modules correctly.
	5. YANG Module		5. YANG Module
	<CODE BEGINS> file "ietf-yang-push@2019-01-29.yang"		This YANG module imports typedefs from [RFC6991], identities from
	module ietf-yang-push {		[RFC8342], the yang-data extension from [RFC8040], and the yang-patch
	yang-version 1.1;		grouping from [RFC8072]. In addition, it imports and augments many
	namespace "urn:ietf:params:xml:ns:yang:ietf-yang-push";		definitions from [I-D.draft-ietf-netconf-subscribed-notifications].
	prefix yp;
	import ietf-yang-types {		<CODE BEGINS> file "ietf-yang-push@2019-02-04.yang"
	prefix yang;		module ietf-yang-push {
	reference		yang-version 1.1;
	"RFC 6991: Common YANG Data Types";		namespace "urn:ietf:params:xml:ns:yang:ietf-yang-push";
	}		prefix yp;
	import ietf-subscribed-notifications {
	prefix sn;
	reference
	"draft-ietf-netconf-subscribed-notifications:
	Customized Subscriptions to a Publisher's Event Streams
	NOTE TO RFC Editor: Please replace above reference to
	draft-ietf-netconf-subscribed-notifications with RFC number
	when published (i.e. RFC xxxx).";
	}
	import ietf-datastores {
	prefix ds;
	reference
	"RFC 8342: Network Management Datastore Architecture (NMDA)";
	}
	import ietf-restconf {
	prefix rc;
	reference
	"RFC 8040: RESTCONF Protocol";
	}
	import ietf-yang-patch {		import ietf-yang-types {
	prefix ypatch;		prefix yang;
	reference		reference
	"RFC 8072: YANG Patch";		"RFC 6991: Common YANG Data Types";
	}		}
	organization "IETF";		import ietf-subscribed-notifications {
	contact		prefix sn;
	"WG Web: <http://tools.ietf.org/wg/netconf/>		reference
	WG List: <mailto:netconf@ietf.org>		"draft-ietf-netconf-subscribed-notifications:
	Editor: Alexander Clemm		Customized Subscriptions to a Publisher's Event Streams
	<mailto:ludwig@clemm.org>		NOTE TO RFC Editor: Please replace above reference to
	Editor: Eric Voit		draft-ietf-netconf-subscribed-notifications with RFC number
	<mailto:evoit@cisco.com>		when published (i.e. RFC xxxx).";
	Editor: Alberto Gonzalez Prieto		}
	<mailto:agonzalezpri@vmware.com>		import ietf-datastores {
			prefix ds;
			reference
			"RFC 8342: Network Management Datastore Architecture (NMDA)";
			}
			import ietf-restconf {
			prefix rc;
			reference
			"RFC 8040: RESTCONF Protocol";
			}
			import ietf-yang-patch {
			prefix ypatch;
			reference
			"RFC 8072: YANG Patch Media Type";
			}
	Editor: Ambika Prasad Tripathy		organization
	<mailto:ambtripa@cisco.com>		"IETF NETCONF Working Group";
	Editor: Einar Nilsen-Nygaard		contact
	<mailto:einarnn@cisco.com>		"WG Web: <http://tools.ietf.org/wg/netconf/>
	Editor: Andy Bierman		WG List: <mailto:netconf@ietf.org>
	<mailto:andy@yumaworks.com>
	Editor: Balazs Lengyel
	<mailto:balazs.lengyel@ericsson.com>";
	description		Editor: Alexander Clemm
	"This module contains YANG specifications for YANG push.		<mailto:ludwig@clemm.org>
	Copyright (c) 2019 IETF Trust and the persons identified as		Editor: Eric Voit
	authors of the code. All rights reserved.		<mailto:evoit@cisco.com>
	Redistribution and use in source and binary forms, with or		Editor: Alberto Gonzalez Prieto
	without modification, is permitted pursuant to, and subject to		<mailto:agonzalezpri@vmware.com>
	the license terms contained in, the Simplified BSD License set		Editor: Ambika Prasad Tripathy
	forth in Section 4.c of the IETF Trust's Legal Provisions		<mailto:ambtripa@cisco.com>
	Relating to IETF Documents		Editor: Einar Nilsen-Nygaard
	(https://trustee.ietf.org/license-info).		<mailto:einarnn@cisco.com>
	This version of this YANG module is part of		Editor: Andy Bierman
	draft-ietf-netconf-yang-push-21; see the RFC itself for full		<mailto:andy@yumaworks.com>
	legal notices.		Editor: Balazs Lengyel
	NOTE TO RFC EDITOR: Please replace above reference to		<mailto:balazs.lengyel@ericsson.com>";
	draft-ietf-netconf-yang-push-21 with RFC number when published		description
	(i.e. RFC xxxx).";		"This module contains YANG specifications for YANG push.
	revision 2019-01-29 {		The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
	description		NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
	"Initial revision.		'MAY', and 'OPTIONAL' in this document are to be interpreted as
	NOTE TO RFC EDITOR:		described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
	(1)Please replace the above revision date to		they appear in all capitals, as shown here.
	the date of RFC publication when published.
	(2) Please replace the date in the file name
	(ietf-yang-push@2019-01-29.yang) to the date of RFC
	publication.
	(3) Please replace the following reference to
	draft-ietf-netconf-yang-push-21 with RFC number when
	published (i.e. RFC xxxx).";
	reference
	"draft-ietf-netconf-yang-push-21";
	}
	/*		Copyright (c) 2019 IETF Trust and the persons identified as
	* FEATURES		authors of the code. All rights reserved.
	*/
	feature on-change {
	description
	"This feature indicates that on-change triggered
	subscriptions are supported.";
	}
	/*		Redistribution and use in source and binary forms, with or
	* IDENTITIES		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
			(https://trustee.ietf.org/license-info).
	/* Error type identities for datastore subscription */		This version of this YANG module is part of RFC XXXX;
			see the RFC itself for full legal notices.";
	identity resync-subscription-error {		// RFC Ed.: replace XXXX with actual RFC number and remove this
			// note.
			revision 2019-02-04 {
	description		description
	"Problem found while attempting to fulfill an		"Initial revision.
	'resync-subscription' RPC request.";		NOTE TO RFC EDITOR:
	}		(1)Please replace the above revision date to
			the date of RFC publication when published.
			(2) Please replace the date in the file name
			(ietf-yang-push@2019-02-04.yang) to the date of RFC
			publication.
			(3) Please replace the following reference to
			draft-ietf-netconf-yang-push-22 with RFC number when
			published (i.e. RFC xxxx).";
			reference
			"draft-ietf-netconf-yang-push-22";
			}
	identity cant-exclude {		/*
	base sn:establish-subscription-error;		* FEATURES
	description		*/
	"Unable to remove the set of 'excluded-changes'. This means
	the publisher is unable to restrict 'push-change-update's to
	just the change types requested for this subscription.";
	}
	identity datastore-not-subscribable {		feature on-change {
	base sn:establish-subscription-error;		description
	base sn:subscription-terminated-reason;		"This feature indicates that on-change triggered subscriptions
	description		are supported.";
	"This is not a subscribable datastore.";		}
	}
	identity no-such-subscription-resync {		/*
	base resync-subscription-error;		* IDENTITIES
	description		*/
	"Referenced subscription doesn't exist. This may be as a
	result of a non-existent subscription ID, an ID which
	belongs to another subscriber, or an ID for configured
	subscription.";
	}
	identity on-change-unsupported {		/* Error type identities for datastore subscription */
	base sn:establish-subscription-error;
	description
	"On-change is not supported for any objects which are
	selectable by this filter.";
	}
	identity on-change-sync-unsupported {
	base sn:establish-subscription-error;
	description
	"Neither sync on start nor resynchronization are supported
	for this subscription. This error will be used for two
	reasons. First if an 'establish-subscription' RPC includes
	'sync-on-start', yet the publisher can't support sending a
	'push-update' for this subscription for reasons other than
	'on-change-unsupported' or 'sync-too-big'. And second,
	if the 'resync-subscription' RPC is invoked either for an
	existing periodic subscription, or for an on-change
	subscription which can't support resynchronization.";
	}
	identity period-unsupported {		identity resync-subscription-error {
	base sn:establish-subscription-error;		description
	base sn:modify-subscription-error;		"Problem found while attempting to fulfill an
	base sn:subscription-suspended-reason;		'resync-subscription' RPC request.";
	description		}
	"Requested time period or dampening-period is too short. This
	can be for both periodic and on-change subscriptions (with or
	without dampening.) Hints suggesting alternative periods may
	be returned as supplemental information.";
	}
	identity update-too-big {		identity cant-exclude {
	base sn:establish-subscription-error;		base sn:establish-subscription-error;
	base sn:modify-subscription-error;		description
	base sn:subscription-suspended-reason;		"Unable to remove the set of 'excluded-changes'. This means
	description		the publisher is unable to restrict 'push-change-update's to
	"Periodic or on-change push update datatrees exceed a maximum		just the change types requested for this subscription.";
	size limit. Hints on estimated size of what was too big may		}
	be returned as supplemental information.";
	}
	identity sync-too-big {		identity datastore-not-subscribable {
	base sn:establish-subscription-error;		base sn:establish-subscription-error;
	base sn:modify-subscription-error;		base sn:subscription-terminated-reason;
	base resync-subscription-error;		description
	base sn:subscription-suspended-reason;		"This is not a subscribable datastore.";
	description		}
	"Sync-on-start or resynchronization datatree exceeds a
	maximum size limit. Hints on estimated size of what was too
	big may be returned as supplemental information.";
	}
	identity unchanging-selection {		identity no-such-subscription-resync {
	base sn:establish-subscription-error;		base resync-subscription-error;
	base sn:modify-subscription-error;		description
	base sn:subscription-terminated-reason;		"Referenced subscription doesn't exist. This may be as a result
	description		of a non-existent subscription ID, an ID which belongs to
	"Selection filter is unlikely to ever select datatree nodes.		another subscriber, or an ID for configured subscription.";
	This means that based on the subscriber's current access		}
	rights, the publisher recognizes that the selection filter is
	unlikely to ever select datatree nodes which change. Examples
	for this might be that node or subtree doesn't exist, read
	access is not permitted for a receiver, or static objects
	that only change at reboot have been chosen.";
	}
	/*		identity on-change-unsupported {
	* TYPE DEFINITIONS		base sn:establish-subscription-error;
	*/		description
			"On-change is not supported for any objects which are
			selectable by this filter.";
			}
	typedef change-type {		identity on-change-sync-unsupported {
	type enumeration {		base sn:establish-subscription-error;
	enum "create" {		description
	description		"Neither sync on start nor resynchronization are supported for
	"A change that refers to the creation of a new datastore		this subscription. This error will be used for two
	node.";		reasons. First if an 'establish-subscription' RPC includes
	}		'sync-on-start', yet the publisher can't support sending a
	enum "delete" {		'push-update' for this subscription for reasons other than
	description		'on-change-unsupported' or 'sync-too-big'. And second, if the
	"A change that refers to the deletion of a datastore		'resync-subscription' RPC is invoked either for an existing
	node.";		periodic subscription, or for an on-change subscription which
	}		can't support resynchronization.";
	enum "insert" {		}
	description
	"A change that refers to the insertion of a new
	user-ordered datastore node.";
	}
	enum "move" {
	description
	"A change that refers to a reordering of the target
	datastore node";
	}
	enum "replace" {
	description
	"A change that refers to a replacement of the target
	datastore node's value.";
	}
	}
	description
	"Specifies different types of datastore changes.";
	reference
	"RFC 8072 section 2.5, with a delta that it is valid for a
	receiver to process an update record which performs a create
	operation on a datastore node the receiver believes exists,
	or to process a delete on a datastore node the receiver
	believes is missing.";
	}
	typedef selection-filter-ref {		identity period-unsupported {
	type leafref {		base sn:establish-subscription-error;
	path "/sn:filters/yp:selection-filter/yp:filter-id";		base sn:modify-subscription-error;
	}		base sn:subscription-suspended-reason;
	description		description
	"This type is used to reference a selection filter.";		"Requested time period or dampening-period is too short. This
	}		can be for both periodic and on-change subscriptions (with or
			without dampening.) Hints suggesting alternative periods may
			be returned as supplemental information.";
			}
	/*		identity update-too-big {
	* GROUP DEFINITIONS		base sn:establish-subscription-error;
	*/		base sn:modify-subscription-error;
			base sn:subscription-suspended-reason;
			description
			"Periodic or on-change push update datatrees exceed a maximum
			size limit. Hints on estimated size of what was too big may
			be returned as supplemental information.";
			}
			identity sync-too-big {
			base sn:establish-subscription-error;
			base sn:modify-subscription-error;
			base resync-subscription-error;
			base sn:subscription-suspended-reason;
			description
			"Sync-on-start or resynchronization datatree exceeds a maximum
			size limit. Hints on estimated size of what was too big may
			be returned as supplemental information.";
			}
	grouping datastore-criteria {		identity unchanging-selection {
	description		base sn:establish-subscription-error;
	"A grouping to define criteria for which selected objects		base sn:modify-subscription-error;
	from a targeted datastore should be included in push		base sn:subscription-terminated-reason;
	updates.";		description
	leaf datastore {		"Selection filter is unlikely to ever select datatree nodes.
			This means that based on the subscriber's current access
			rights, the publisher recognizes that the selection filter is
			unlikely to ever select datatree nodes which change. Examples
			for this might be that node or subtree doesn't exist, read
			access is not permitted for a receiver, or static objects that
			only change at reboot have been chosen.";
			}
			/*
			* TYPE DEFINITIONS
			*/
			typedef change-type {
			type enumeration {
			enum create {
			description
			"A change that refers to the creation of a new datastore
			node.";
			}
			enum delete {
			description
			"A change that refers to the deletion of a datastore
			node.";
			}
			enum insert {
			description
			"A change that refers to the insertion of a new
			user-ordered datastore node.";
			}
			enum move {
			description
			"A change that refers to a reordering of the target
			datastore node.";
			}
			enum replace {
			description
			"A change that refers to a replacement of the target
			datastore node's value.";
			}
			}
			description
			"Specifies different types of datastore changes.
			This type is based on the edit operations defined for YANG
			Patch, with the difference that it is valid for a receiver to
			process an update record which performs a create operation on
			a datastore node the receiver believes exists, or to process a
			delete on a datastore node the receiver believes is missing.";
			reference
			"RFC 8072: YANG Patch Media Type, section 2.5";
			}
			typedef selection-filter-ref {
			type leafref {
			path "/sn:filters/yp:selection-filter/yp:filter-id";
			}
			description
			"This type is used to reference a selection filter.";
			}
			typedef centiseconds {
			type uint32;
			description
			"A period of time, measured in units of 0.01 seconds.";
			}
			/*
			* GROUP DEFINITIONS
			*/
			grouping datastore-criteria {
			description
			"A grouping to define criteria for which selected objects
			from a targeted datastore should be included in push
			updates.";
			leaf datastore {
	type identityref {		type identityref {
	base ds:datastore;		base ds:datastore;
	}		}
	mandatory true;		mandatory true;
	description		description
	"Datastore from which to retrieve data.";		"Datastore from which to retrieve data.";
	}		}
	uses selection-filter-objects;		uses selection-filter-objects;
	}		}
	grouping selection-filter-types {		grouping selection-filter-types {
	description		description
	"This grouping defines the types of selectors for objects		"This grouping defines the types of selectors for objects
	from a datastore.";		from a datastore.";
	choice filter-spec {		choice filter-spec {
	description		description
	"The content filter specification for this request.";		"The content filter specification for this request.";
	anydata datastore-subtree-filter {		anydata datastore-subtree-filter {
	if-feature "sn:subtree";		if-feature "sn:subtree";
	description		description
	"This parameter identifies the portions of the		"This parameter identifies the portions of the
	target datastore to retrieve.";		target datastore to retrieve.";
	reference		reference
	"RFC 6241: Network Configuration Protocol, Section 6.";		"RFC 6241: Network Configuration Protocol, Section 6.";
	}		}
	leaf datastore-xpath-filter {		leaf datastore-xpath-filter {
	if-feature "sn:xpath";		if-feature "sn:xpath";
	type yang:xpath1.0;		type yang:xpath1.0;
	description		description
	"This parameter contains an XPath expression identifying		"This parameter contains an XPath expression identifying
	the portions of the target datastore to retrieve.		the portions of the target datastore to retrieve.
	If the expression returns a node-set, all nodes in the
	node-set are selected by the filter. Otherwise, if the
	expression does not return a node-set, the filter
	doesn't select any nodes.
	The expression is evaluated in the following XPath
	context:
	o The set of namespace declarations are those in scope
	on the 'datastore-xpath-filter' leaf element.
	o The set of variable bindings is empty.
	o The function library is the core function library, and
	the XPath functions defined in section 10 in RFC 7950.
	o The context node is the root node of the target
	datastore.";
	}
	}
	}
	grouping selection-filter-objects {		If the expression returns a node-set, all nodes in the
	description		node-set are selected by the filter. Otherwise, if the
	"This grouping defines a selector for objects from a		expression does not return a node-set, the filter
	datastore.";		doesn't select any nodes.
	choice selection-filter {
	description
	"The source of the selection filter applied to the
	subscription. This will come either referenced from a
	global list, or be provided within the subscription
	itself.";
	case by-reference {
	description
	"Incorporate a filter that has been configured
	separately.";
	leaf selection-filter-ref {
	type selection-filter-ref;
	mandatory true;
	description
	"References an existing selection filter which is to be
	applied to the subscription.";
	}
	}
	case within-subscription {
	description
	"Local definition allows a filter to have the same
	lifecycle as the subscription.";
	uses selection-filter-types;
	}		The expression is evaluated in the following XPath
	}		context:
	}
	grouping update-policy-modifiable {		o The set of namespace declarations is the set of prefix
	description		and namespace pairs for all YANG modules implemented
	"This grouping describes the datastore specific subscription		by the server, where the prefix is the YANG module
	conditions that can be changed during the lifetime of the		name and the namespace is as defined by the
	subscription.";		'namespace' statement in the YANG module.
	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 yang:timeticks;
	mandatory true;
	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 {
	if-feature "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 yang:timeticks;
	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.";
	}
	}
	}
	}
	}
	grouping update-policy {		If the leaf is encoded in XML, all namespace
	description		declarations in scope on the 'stream-xpath-filter'
	"This grouping describes the datastore-specific subscription		leaf element are added to the set of namespace
	conditions of a subscription.";		declarations. If a prefix found in the XML is
	uses update-policy-modifiable {		already present in the set of namespace declarations,
	augment "update-trigger/on-change/on-change" {		the namespace in the XML is used.
	description
	"Includes objects not modifiable once subscription is
	established.";
	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.";
	}
	leaf-list excluded-change {
	type change-type;
	description
	"Use to restrict which changes trigger an update.
	For example, if modify is excluded, only creation and
	deletion of objects is reported.";
	}
	}
	}
	}
	grouping hints {		o The set of variable bindings is empty.
	description
	"Parameters associated with some error for a subscription
	made upon a datastore.";
	leaf period-hint {
	type yang:timeticks;
	description
	"Returned when the requested time period is too short. This
	hint can assert a viable period for either a periodic push
	cadence or an on-change dampening interval.";
	}
	leaf filter-failure-hint {
	type string;
	description
	"Information describing where and/or why a provided filter
	was unsupportable for a subscription.";
	}
	leaf object-count-estimate {
	type uint32;
	description
	"If there are too many objects which could potentially be
	returned by the selection filter, this identifies the
	estimate of the number of objects which the filter would
	potentially pass.";
	}
	leaf object-count-limit {
	type uint32;
	description
	"If there are too many objects which could be returned by
	the selection filter, this identifies the upper limit of
	the publisher's ability to service for this subscription.";
	}
	leaf kilobytes-estimate {
	type uint32;
	description
	"If the returned information could be beyond the capacity
	of the publisher, this would identify the data size which
	could result from this selection filter.";
	}
	leaf kilobytes-limit {
	type uint32;
	description
	"If the returned information would be beyond the capacity
	of the publisher, this identifies the upper limit of the
	publisher's ability to service for this subscription.";
	}
	}
	/*		o The function library is the core function library, and
	* RPCs		the XPath functions defined in section 10 in RFC 7950.
	*/
	rpc resync-subscription {		o The context node is the root node of the target
	if-feature "on-change";		datastore.";
	description		}
	"This RPC allows a subscriber of an active on-change		}
	subscription to request a full push of objects.		}
	A successful invocation results in a push-update of all
	datastore nodes that the subscriber is permitted to access.
	This RPC can only be invoked on the same session on which the
	subscription is currently active. In case of an error, a
	resync-subscription-error is sent as part of an error
	response.";
	input {
	leaf id {
	type sn:subscription-id;
	mandatory true;
	description
	"Identifier of the subscription that is to be resynced.";
	}
	}
	}
	rc:yang-data resync-subscription-error {		grouping selection-filter-objects {
	container resync-subscription-error {		description
	description		"This grouping defines a selector for objects from a
	"If a 'resync-subscription' RPC fails, the subscription is		datastore.";
	not resynced and the RPC error response MUST indicate the		choice selection-filter {
	reason for this failure. This yang-data MAY be inserted as		description
	structured data within a subscription's RPC error response		"The source of the selection filter applied to the
	to indicate the failure reason.";		subscription. This will come either referenced from a global
	leaf reason {		list, or be provided within the subscription itself.";
	type identityref {		case by-reference {
	base resync-subscription-error;		description
	}		"Incorporate a filter that has been configured
	mandatory true;		separately.";
	description		leaf selection-filter-ref {
	"Indicates the reason why the publisher has declined a		type selection-filter-ref;
	request for subscription resynchronization.";		mandatory true;
	}		description
	uses hints;		"References an existing selection filter which is to be
	}		applied to the subscription.";
	}		}
			}
			case within-subscription {
			description
			"Local definition allows a filter to have the same
			lifecycle as the subscription.";
			uses selection-filter-types;
			}
			}
			}
	augment "/sn:establish-subscription/sn:input" {		grouping update-policy-modifiable {
	description		description
	"This augmentation adds additional subscription parameters		"This grouping describes the datastore specific subscription
	that apply specifically to datastore updates to RPC input.";		conditions that can be changed during the lifetime of the
	uses update-policy;		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 centiseconds;
			mandatory true;
			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 {
			if-feature "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 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.";
			}
			}
			}
			}
			}
	augment "/sn:establish-subscription/sn:input/sn:target" {		grouping update-policy {
	description		description
	"This augmentation adds the datastore as a valid target		"This grouping describes the datastore-specific subscription
	for the subscription to RPC input.";		conditions of a subscription.";
	case datastore {		uses update-policy-modifiable {
	description		augment "update-trigger/on-change/on-change" {
	"Information specifying the parameters of an request for a		description
	datastore subscription.";		"Includes objects not modifiable once subscription is
	uses datastore-criteria;		established.";
	}		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.";
			}
			leaf-list excluded-change {
			type change-type;
			description
			"Use to restrict which changes trigger an update. For
			example, if modify is excluded, only creation and
			deletion of objects is reported.";
			}
			}
			}
			}
			grouping hints {
			description
			"Parameters associated with some error for a subscription
			made upon a datastore.";
			leaf period-hint {
			type centiseconds;
			description
			"Returned when the requested time period is too short. This
			hint can assert a viable period for either a periodic push
			cadence or an on-change dampening interval.";
			}
			leaf filter-failure-hint {
			type string;
			description
			"Information describing where and/or why a provided filter
			was unsupportable for a subscription.";
			}
			leaf object-count-estimate {
			type uint32;
			description
			"If there are too many objects which could potentially be
			returned by the selection filter, this identifies the
			estimate of the number of objects which the filter would
			potentially pass.";
			}
			leaf object-count-limit {
			type uint32;
			description
			"If there are too many objects which could be returned by
			the selection filter, this identifies the upper limit of
			the publisher's ability to service for this subscription.";
			}
			leaf kilobytes-estimate {
			type uint32;
			description
			"If the returned information could be beyond the capacity
			of the publisher, this would identify the data size which
			could result from this selection filter.";
			}
			leaf kilobytes-limit {
			type uint32;
			description
			"If the returned information would be beyond the capacity
			of the publisher, this identifies the upper limit of the
			publisher's ability to service for this subscription.";
			}
			}
			/*
			* RPCs
			*/
	rc:yang-data establish-subscription-datastore-error-info {		rpc resync-subscription {
	container establish-subscription-datastore-error-info {		if-feature "on-change";
	description		description
	"If any 'establish-subscription' RPC parameters are		"This RPC allows a subscriber of an active on-change
	unsupportable against the datastore, a subscription is not		subscription to request a full push of objects.
	created and the RPC error response MUST indicate the reason
	why the subscription failed to be created. This yang-data
	MAY be inserted as structured data within a subscription's
	RPC error response to indicate the failure reason. This
	yang-data MUST be inserted if hints are to be provided back
	to the subscriber.";
	leaf reason {
	type identityref {
	base sn:establish-subscription-error;
	}
	description
	"Indicates the reason why the subscription has failed to
	be created to a targeted datastore.";
	}
	uses hints;
	}		A successful invocation results in a push-update of all
	}		datastore nodes that the subscriber is permitted to access.
			This RPC can only be invoked on the same session on which the
			subscription is currently active. In case of an error, a
			resync-subscription-error is sent as part of an error
			response.";
			input {
			leaf id {
			type sn:subscription-id;
			mandatory true;
			description
			"Identifier of the subscription that is to be resynced.";
			}
			}
			}
	augment "/sn:modify-subscription/sn:input" {		rc:yang-data resync-subscription-error {
	description		container resync-subscription-error {
	"This augmentation adds additional subscription parameters		description
	specific to datastore updates.";		"If a 'resync-subscription' RPC fails, the subscription is
	uses update-policy-modifiable;		not resynced and the RPC error response MUST indicate the
	}		reason for this failure. This yang-data MAY be inserted as
			structured data within a subscription's RPC error response
			to indicate the failure reason.";
			leaf reason {
			type identityref {
			base resync-subscription-error;
			}
			mandatory true;
			description
			"Indicates the reason why the publisher has declined a
			request for subscription resynchronization.";
			}
			uses hints;
			}
			}
	augment "/sn:modify-subscription/sn:input/sn:target" {		augment "/sn:establish-subscription/sn:input" {
	description		description
	"This augmentation adds the datastore as a valid target		"This augmentation adds additional subscription parameters
	for the subscription to RPC input.";		that apply specifically to datastore updates to RPC input.";
	case datastore {		uses update-policy;
	description		}
	"Information specifying the parameters of an request for a
	datastore subscription.";
	uses datastore-criteria;
	}
	}
	rc:yang-data modify-subscription-datastore-error-info {		augment "/sn:establish-subscription/sn:input/sn:target" {
	container modify-subscription-datastore-error-info {		description
	description		"This augmentation adds the datastore as a valid target
	"This yang-data MAY be provided as part of a subscription's		for the subscription to RPC input.";
	RPC error response when there is a failure of a		case datastore {
	'modify-subscription' RPC which has been made against a		description
	datastore. This yang-data MUST be used if hints are to be		"Information specifying the parameters of an request for a
	provides back to the subscriber.";		datastore subscription.";
	leaf reason {		uses datastore-criteria;
	type identityref {		}
	base sn:modify-subscription-error;		}
	}
	description
	"Indicates the reason why the subscription has failed to
	be modified.";
	}
	uses hints;
	}
	}
	/*		rc:yang-data establish-subscription-datastore-error-info {
	* NOTIFICATIONS		container establish-subscription-datastore-error-info {
	*/		description
			"If any 'establish-subscription' RPC parameters are
			unsupportable against the datastore, a subscription is not
			created and the RPC error response MUST indicate the reason
			why the subscription failed to be created. This yang-data
			MAY be inserted as structured data within a subscription's
			RPC error response to indicate the failure reason. This
			yang-data MUST be inserted if hints are to be provided back
			to the subscriber.";
			leaf reason {
			type identityref {
			base sn:establish-subscription-error;
			}
			description
			"Indicates the reason why the subscription has failed to
			be created to a targeted datastore.";
			}
			uses hints;
			}
			}
	notification push-update {		augment "/sn:modify-subscription/sn:input" {
	description		description
	"This notification contains a push update, containing data		"This augmentation adds additional subscription parameters
	subscribed to via a subscription. This notification is sent		specific to datastore updates.";
	for periodic updates, for a periodic subscription. It can		uses update-policy-modifiable;
	also be used for synchronization updates of an on-change		}
	subscription. This notification shall only be sent to		augment "/sn:modify-subscription/sn:input/sn:target" {
	receivers of a subscription. It does not constitute a		description
	general-purpose notification that would be subscribable as		"This augmentation adds the datastore as a valid target
	part of the NETCONF event stream by any receiver.";		for the subscription to RPC input.";
	leaf id {		case datastore {
	type sn:subscription-id;		description
	description		"Information specifying the parameters of an request for a
	"This references the subscription which drove the		datastore subscription.";
	notification to be sent.";		uses datastore-criteria;
	}		}
	anydata datastore-contents {		}
	description
	"This contains the updated data. It constitutes a snapshot
	at the time-of-update of the set of data that has been
	subscribed to. The snapshot corresponds to the same
	snapshot that would be returned in a corresponding get
	operation with the same selection filter parameters
	applied.";
	}
	leaf incomplete-update {
	type empty;
	description
	"This is a flag which indicates that not all datastore
	nodes subscribed to are included with this update. In
	other words, the publisher has failed to fulfill its full
	subscription obligations, and despite its best efforts is
	providing an incomplete set of objects.";
	}
	}
	notification push-change-update {		rc:yang-data modify-subscription-datastore-error-info {
	if-feature "on-change";		container modify-subscription-datastore-error-info {
	description		description
	"This notification contains an on-change push update. This		"This yang-data MAY be provided as part of a subscription's
	notification shall only be sent to the receivers of a		RPC error response when there is a failure of a
	subscription; it does not constitute a general-purpose		'modify-subscription' RPC which has been made against a
	notification.";		datastore. This yang-data MUST be used if hints are to be
	leaf id {		provides back to the subscriber.";
	type sn:subscription-id;		leaf reason {
	description		type identityref {
	"This references the subscription which drove the		base sn:modify-subscription-error;
	notification to be sent.";		}
	}		description
	container datastore-changes {		"Indicates the reason why the subscription has failed to
	description		be modified.";
	"This contains the set of datastore changes of the		}
	target datastore starting at the time of the		uses hints;
	previous update, per the terms of the subscription.		}
	The datastore changes are encoded per RFC 8027		}
	(YANG Patch).";
	uses ypatch:yang-patch;
	}
	leaf incomplete-update {
	type empty;
	description
	"The presence of this object indicates not all changes which
	have occurred since the last update are included with this
	update. In other words, the publisher has failed to
	fulfill its full subscription obligations, for example in
	cases where it was not able to keep up with a change
	burst.";
	}
	}
	augment "/sn:subscription-started" {		/*
	description		* NOTIFICATIONS
	"This augmentation adds datastore-specific objects to		*/
	the notification that a subscription has started.";
	uses update-policy;
	}
	augment "/sn:subscription-started/sn:target" {		notification push-update {
	description		description
	"This augmentation allows the datastore to be included as		"This notification contains a push update, containing data
	part of the notification that a subscription has started.";		subscribed to via a subscription. This notification is sent
	case datastore {		for periodic updates, for a periodic subscription. It can
			also be used for synchronization updates of an on-change
			subscription. This notification shall only be sent to
			receivers of a subscription. It does not constitute a
			general-purpose notification that would be subscribable as
			part of the NETCONF event stream by any receiver.";
			leaf id {
			type sn:subscription-id;
			description
			"This references the subscription which drove the
			notification to be sent.";
			}
			anydata datastore-contents {
			description
			"This contains the updated data. It constitutes a snapshot
			at the time-of-update of the set of data that has been
			subscribed to. The snapshot corresponds to the same
			snapshot that would be returned in a corresponding get
			operation with the same selection filter parameters
			applied.";
			}
			leaf incomplete-update {
			type empty;
			description
			"This is a flag which indicates that not all datastore
			nodes subscribed to are included with this update. In
			other words, the publisher has failed to fulfill its full
			subscription obligations, and despite its best efforts is
			providing an incomplete set of objects.";
			}
			}
			notification push-change-update {
			if-feature "on-change";
			description
			"This notification contains an on-change push update. This
			notification shall only be sent to the receivers of a
			subscription; it does not constitute a general-purpose
			notification.";
			leaf id {
			type sn:subscription-id;
			description
			"This references the subscription which drove the
			notification to be sent.";
			}
			container datastore-changes {
			description
			"This contains the set of datastore changes of the target
			datastore starting at the time of the previous update, per
			the terms of the subscription.";
			uses ypatch:yang-patch;
			}
			leaf incomplete-update {
			type empty;
			description
			"The presence of this object indicates not all changes which
			have occurred since the last update are included with this
			update. In other words, the publisher has failed to
			fulfill its full subscription obligations, for example in
			cases where it was not able to keep up with a change
			burst.";
			}
			}
			augment "/sn:subscription-started" {
			description
			"This augmentation adds datastore-specific objects to
			the notification that a subscription has started.";
			uses update-policy;
			}
			augment "/sn:subscription-started/sn:target" {
			description
			"This augmentation allows the datastore to be included as
			part of the notification that a subscription has started.";
			case datastore {
	uses datastore-criteria {		uses datastore-criteria {
	refine "selection-filter/within-subscription" {		refine "selection-filter/within-subscription" {
	description		description
	"Specifies the selection filter and where it		"Specifies the selection filter and where it originated
	originated from. If the 'selection-filter-ref' is		from. If the 'selection-filter-ref' is populated, the
	populated, the filter within the subscription came		filter within the subscription came from the 'filters'
	from the 'filters' container. Otherwise it is		container. Otherwise it is populated in-line as part of
	populated in-line as part of the subscription itself.";		the subscription itself.";
	}		}
	}		}
	}		}
	}		}
	augment "/sn:subscription-modified" {		augment "/sn:subscription-modified" {
	description		description
	"This augmentation adds datastore-specific objects to		"This augmentation adds datastore-specific objects to
	the notification that a subscription has been modified.";		the notification that a subscription has been modified.";
	uses update-policy;		uses update-policy;
	}		}
	augment "/sn:subscription-modified/sn:target" {		augment "/sn:subscription-modified/sn:target" {
	description		description
	"This augmentation allows the datastore to be included as		"This augmentation allows the datastore to be included as
	part of the notification that a subscription has been		part of the notification that a subscription has been
	modified.";		modified.";
	case datastore {		case datastore {
	uses datastore-criteria {		uses datastore-criteria {
	refine "selection-filter/within-subscription" {		refine "selection-filter/within-subscription" {
	description		description
	"Specifies where the selection filter, and where it		"Specifies where the selection filter, and where it came
	came from within the subscription and then populated		from within the subscription and then populated within
	within this notification. If the		this notification. If the 'selection-filter-ref' is
	'selection-filter-ref' is populated, the filter within		populated, the filter within the subscription came from
	the subscription came from the 'filters' container.		the 'filters' container. Otherwise it is populated
	Otherwise it is populated in-line as part of the		in-line as part of the subscription itself.";
	subscription itself.";		}
	}		}
	}		}
	}		}
	}
	/*		/*
	* DATA NODES		* DATA NODES
	*/		*/
	augment "/sn:filters" {		augment "/sn:filters" {
	description		description
	"This augmentation allows the datastore to be included as part		"This augmentation allows the datastore to be included as part
	of the selection filtering criteria for a subscription.";		of the selection filtering criteria for a subscription.";
	list selection-filter {		list selection-filter {
	key "filter-id";		key "filter-id";
	description		description
	"A list of pre-configured filters that can be applied		"A list of pre-configured filters that can be applied
	to datastore subscriptions.";		to datastore subscriptions.";
	leaf filter-id {		leaf filter-id {
	type string;		type string;
	description		description
	"An identifier to differentiate between selection		"An identifier to differentiate between selection
	filters.";		filters.";
	}		}
	uses selection-filter-types;		uses selection-filter-types;
	}		}
	}		}
	augment "/sn:subscriptions/sn:subscription" {
	when "yp:datastore";		augment "/sn:subscriptions/sn:subscription" {
	description		when 'yp:datastore';
	"This augmentation adds many datastore specific objects to a		description
	subscription.";		"This augmentation adds many datastore specific objects to a
	uses update-policy;		subscription.";
	}		uses update-policy;
	augment "/sn:subscriptions/sn:subscription/sn:target" {		}
	description
	"This augmentation allows the datastore to be included as		augment "/sn:subscriptions/sn:subscription/sn:target" {
	part of the selection filtering criteria for a subscription.";		description
	case datastore {		"This augmentation allows the datastore to be included as
			part of the selection filtering criteria for a subscription.";
			case datastore {
	uses datastore-criteria;		uses datastore-criteria;
	}		}
	}		}
	}		}
	<CODE ENDS>
			<CODE ENDS>
	6. IANA Considerations		6. IANA Considerations
	This document registers the following namespace URI in the "IETF XML		This document registers the following namespace URI in the "IETF XML
	Registry" [RFC3688]:		Registry" [RFC3688]:
	URI: urn:ietf:params:xml:ns:yang:ietf-yang-push		URI: urn:ietf:params:xml:ns:yang:ietf-yang-push
	Registrant Contact: The IESG.		Registrant Contact: The IESG.
	XML: N/A; the requested URI is an XML namespace.		XML: N/A; the requested URI is an XML namespace.
	skipping to change at page 46, line 47 ¶		skipping to change at page 48, line 36 ¶
	Reference: draft-ietf-netconf-yang-push-21.txt (RFC form)		Reference: draft-ietf-netconf-yang-push-21.txt (RFC form)
	7. Security Considerations		7. Security Considerations
	The YANG module specified in this document defines a schema for data		The YANG module specified in this document defines a schema for data
	that is designed to be accessed via network management protocols such		that is designed to be accessed via network management protocols such
	as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer		as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer
	is the secure transport layer, and the mandatory-to-implement secure		is the secure transport layer, and the mandatory-to-implement secure
	transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer		transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer
	is HTTPS, and the mandatory-to-implement secure transport is TLS		is HTTPS, and the mandatory-to-implement secure transport is TLS
	[RFC5246].		[RFC8446].
	The Network Configuration Access Control Model (NACM) [RFC8341]		The Network Configuration Access Control Model (NACM) [RFC8341]
	provides the means to restrict access for particular NETCONF or		provides the means to restrict access for particular NETCONF or
	RESTCONF users to a preconfigured subset of all available NETCONF or		RESTCONF users to a preconfigured subset of all available NETCONF or
	RESTCONF protocol operations and content.		RESTCONF protocol operations and content.
	There are a number of data nodes defined in this YANG module that are		There are a number of data nodes defined in this YANG module that are
	writable/creatable/deletable (i.e., config true, which is the		writable/creatable/deletable (i.e., config true, which is the
	default). These data nodes may be considered sensitive or vulnerable		default). These data nodes may be considered sensitive or vulnerable
	in some network environments. Write operations (e.g., edit-config)		in some network environments. Write operations (e.g., edit-config)
	skipping to change at page 48, line 22 ¶		skipping to change at page 50, line 15 ¶
	9. References		9. References
	9.1. Normative References		9.1. Normative References
	[I-D.draft-ietf-netconf-subscribed-notifications]		[I-D.draft-ietf-netconf-subscribed-notifications]
	Voit, E., Clemm, A., Gonzalez Prieto, A., Tripathy, A.,		Voit, E., Clemm, A., Gonzalez Prieto, A., Tripathy, A.,
	and E. Nilsen-Nygaard, "Subscription to YANG Event		and E. Nilsen-Nygaard, "Subscription to YANG Event
	NOtifications", draft-ietf-netconf-subscribed-		NOtifications", draft-ietf-netconf-subscribed-
	notifications-22 (work in progress), January 2019.		notifications-22 (work in progress), January 2019.
			[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
			Requirement Levels", BCP 14, RFC 2119,
			DOI 10.17487/RFC2119, March 1997,
			<https://www.rfc-editor.org/info/rfc2119>.
	[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,		[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
	DOI 10.17487/RFC3688, January 2004,		DOI 10.17487/RFC3688, January 2004,
	<https://www.rfc-editor.org/info/rfc3688>.		<https://www.rfc-editor.org/info/rfc3688>.
	[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for		[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
	the Network Configuration Protocol (NETCONF)", RFC 6020,		the Network Configuration Protocol (NETCONF)", RFC 6020,
	DOI 10.17487/RFC6020, October 2010,		DOI 10.17487/RFC6020, October 2010,
	<https://www.rfc-editor.org/info/rfc6020>.		<https://www.rfc-editor.org/info/rfc6020>.
	[RFC6470] Bierman, A., "Network Configuration Protocol (NETCONF)
	Base Notifications", RFC 6470, DOI 10.17487/RFC6470,
	February 2012, <https://www.rfc-editor.org/info/rfc6470>.
	[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",		[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
	RFC 6991, DOI 10.17487/RFC6991, July 2013,		RFC 6991, DOI 10.17487/RFC6991, July 2013,
	<https://www.rfc-editor.org/info/rfc6991>.		<https://www.rfc-editor.org/info/rfc6991>.
	[RFC7895] Bierman, A., Bjorklund, M., and K. Watsen, "YANG Module		[RFC7895] Bierman, A., Bjorklund, M., and K. Watsen, "YANG Module
	Library", RFC 7895, DOI 10.17487/RFC7895, June 2016,		Library", RFC 7895, DOI 10.17487/RFC7895, June 2016,
	<https://www.rfc-editor.org/info/rfc7895>.		<https://www.rfc-editor.org/info/rfc7895>.
	[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",		[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
	RFC 7950, DOI 10.17487/RFC7950, August 2016,		RFC 7950, DOI 10.17487/RFC7950, August 2016,
	<https://www.rfc-editor.org/info/rfc7950>.		<https://www.rfc-editor.org/info/rfc7950>.
	[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF		[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
	Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,		Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
	<https://www.rfc-editor.org/info/rfc8040>.		<https://www.rfc-editor.org/info/rfc8040>.
	[RFC8072] Bierman, A., Bjorklund, M., and K. Watsen, "YANG Patch		[RFC8072] Bierman, A., Bjorklund, M., and K. Watsen, "YANG Patch
	Media Type", RFC 8072, DOI 10.17487/RFC8072, February		Media Type", RFC 8072, DOI 10.17487/RFC8072, February
	2017, <https://www.rfc-editor.org/info/rfc8072>.		2017, <https://www.rfc-editor.org/info/rfc8072>.
			[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
			2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
			May 2017, <https://www.rfc-editor.org/info/rfc8174>.
	[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration		[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
	Access Control Model", STD 91, RFC 8341,		Access Control Model", STD 91, RFC 8341,
	DOI 10.17487/RFC8341, March 2018,		DOI 10.17487/RFC8341, March 2018,
	<https://www.rfc-editor.org/info/rfc8341>.		<https://www.rfc-editor.org/info/rfc8341>.
	[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,		[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
	and R. Wilton, "Network Management Datastore Architecture		and R. Wilton, "Network Management Datastore Architecture
	(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,		(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
	<https://www.rfc-editor.org/info/rfc8342>.		<https://www.rfc-editor.org/info/rfc8342>.
	9.2. Informative References		9.2. Informative References
	[I-D.draft-ietf-netconf-netconf-event-notifications]		[I-D.draft-ietf-netconf-netconf-event-notifications]
	Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,		Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
	E., and A. Tripathy, "Dynamic subscription to YANG Events		E., and A. Tripathy, "Dynamic subscription to YANG Events
	and DAtastores over NETCONF", January 2019.		and DAtastores over NETCONF", January 2019.
	[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
	(TLS) Protocol Version 1.2", RFC 5246,
	DOI 10.17487/RFC5246, August 2008,
	<https://www.rfc-editor.org/info/rfc5246>.
	[RFC5277] Chisholm, S. and H. Trevino, "NETCONF Event
	Notifications", RFC 5277, DOI 10.17487/RFC5277, July 2008,
	<https://www.rfc-editor.org/info/rfc5277>.
	[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,		[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
	and A. Bierman, Ed., "Network Configuration Protocol		and A. Bierman, Ed., "Network Configuration Protocol
	(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,		(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
	<https://www.rfc-editor.org/info/rfc6241>.		<https://www.rfc-editor.org/info/rfc6241>.
	[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure		[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
	Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,		Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
	<https://www.rfc-editor.org/info/rfc6242>.		<https://www.rfc-editor.org/info/rfc6242>.
	[RFC7923] Voit, E., Clemm, A., and A. Gonzalez Prieto, "Requirements		[RFC7923] Voit, E., Clemm, A., and A. Gonzalez Prieto, "Requirements
	skipping to change at page 50, line 9 ¶		skipping to change at page 51, line 44 ¶
	<https://www.rfc-editor.org/info/rfc7923>.		<https://www.rfc-editor.org/info/rfc7923>.
	[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",		[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
	BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,		BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
	<https://www.rfc-editor.org/info/rfc8340>.		<https://www.rfc-editor.org/info/rfc8340>.
	[RFC8343] Bjorklund, M., "A YANG Data Model for Interface		[RFC8343] Bjorklund, M., "A YANG Data Model for Interface
	Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,		Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,
	<https://www.rfc-editor.org/info/rfc8343>.		<https://www.rfc-editor.org/info/rfc8343>.
	Appendix A. Appendix A: Subscription Errors		[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
			Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
			<https://www.rfc-editor.org/info/rfc8446>.
			Appendix A. Appendix A: Subscription Errors
	A.1. RPC Failures		A.1. RPC Failures
	Rejection of an RPC for any reason is indicated by via RPC error		Rejection of an RPC for any reason is indicated by via RPC error
	response from the publisher. Valid RPC errors returned include both		response from the publisher. Valid RPC errors returned include both
	existing transport layer RPC error codes, such as those seen with		existing transport layer RPC error codes, such as those seen with
	NETCONF in [RFC6241], as well as subscription specific errors such as		NETCONF in [RFC6241], as well as subscription specific errors such as
	those defined within the YANG model. As a result, how subscription		those defined within the YANG model. As a result, how subscription
	errors are encoded within an RPC error response is transport		errors are encoded within an RPC error response is transport
	dependent.		dependent.
	References to specific identities within the either the subscribed-		References to specific identities in the ietf-subscribed-
	notifications YANG model or the yang-push YANG model may be returned		notifications YANG model or the ietf-yang-push YANG model may be
	as part of the error responses resulting from failed attempts at		returned as part of the error responses resulting from failed
	datastore subscription. Following are valid errors per RPC (note:		attempts at datastore subscription. For errors defined as part of
	throughout this section the prefix 'sn' indicates an item imported		ietf-subscribed-notifications, please refer to
	from the subscribed-notifications.yang model):		[I-D.draft-ietf-netconf-subscribed-notifications]. The errors
			introduced in this document, grouped per RPC, are as follows:
	establish-subscription modify-subscription
	---------------------- -------------------
	cant-exclude sn:filter-unsupported
	datastore-not-subscribable sn:insufficient-resources
	sn:dscp-unavailable sn:no-such-subscription
	sn:filter-unsupported period-unsupported
	sn:insufficient-resources update-too-big
	on-change-unsupported sync-too-big
	on-change-sync-unsupported unchanging-selection
	period-unsupported
	update-too-big resync-subscription
	sync-too-big --------------------
	unchanging-selection no-such-subscription-resync
	sync-too-big
	delete-subscription kill-subscription		establish-subscription modify-subscription
	---------------------- -----------------		---------------------- -------------------
	sn:no-such-subscription sn:no-such-subscription		cant-exclude period-unsupported
			datastore-not-subscribable update-too-big
			on-change-unsupported sync-too-big
			on-change-sync-unsupported unchanging-selection
			period-unsupported
			update-too-big resync-subscription
			sync-too-big --------------------
			unchanging-selection no-such-subscription-resync
			sync-too-big
	There is one final set of transport independent RPC error elements		There is one final set of transport independent RPC error elements
	included in the YANG model. These are the following four yang-data		included in the YANG model. These are the following four yang-data
	structures for failed datastore subscriptions:		structures for failed datastore subscriptions:
	1. yang-data establish-subscription-error-datastore		1. yang-data establish-subscription-error-datastore
	This MUST be returned if information identifying the reason for an		This MUST be returned if information identifying the reason for an
	RPC error has not been placed elsewhere within the transport		RPC error has not been placed elsewhere within the transport
	portion of a failed "establish-subscription" RPC response. This		portion of a failed "establish-subscription" RPC response. This
	MUST be sent if hints are included.		MUST be sent if hints are included.
	skipping to change at page 51, line 33 ¶		skipping to change at page 53, line 33 ¶
	4. yang-data resync-subscription-error		4. yang-data resync-subscription-error
	This MUST be returned if information identifying the reason for an		This MUST be returned if information identifying the reason for an
	RPC error has not been placed elsewhere within the transport		RPC error has not been placed elsewhere within the transport
	portion of a failed "resync-subscription" RPC response.		portion of a failed "resync-subscription" RPC response.
	A.2. Notifications of Failure		A.2. Notifications of Failure
	A subscription may be unexpectedly terminated or suspended		A subscription may be unexpectedly terminated or suspended
	independent of any RPC or configuration operation. In such cases,		independent of any RPC or configuration operation. In such cases,
	indications of such a failure MUST be provided. To accomplish this,		indications of such a failure MUST be provided. To accomplish this,
	the following types of error identities may be returned within the		a number of errors can be returned as part of the corresponding
	corresponding subscription state change notification:		subscription state change notification. For this purpose, the
			following error identities have been introduced in this document, in
			addition to those that were already defined in
			[I-D.draft-ietf-netconf-subscribed-notifications]:
	subscription-terminated subscription-suspended		subscription-terminated subscription-suspended
	----------------------- ----------------------		----------------------- ----------------------
	datastore-not-subscribable sn:insufficient-resources		datastore-not-subscribable period-unsupported
	sn:filter-unavailable period-unsupported		unchanging-selection update-too-big
	sn:no-such-subscription update-too-big		synchronization-size
	sn:suspension-timeout synchronization-size
	unchanging-selection
	Appendix B. Changes Between Revisions		Appendix B. Changes Between Revisions
	(To be removed by RFC editor prior to publication)		(To be removed by RFC editor prior to publication)
			v21 - v22
			o Minor updates per Martin Bjorklund's YANG doctor review.
	v20 - v21		v20 - v21
	o Minor updates, simplifying RPC input conditions.		o Minor updates, simplifying RPC input conditions.
	v19 - v20		v19 - v20
	o Minor updates per WGLC comments.		o Minor updates per WGLC comments.
	v18 - v19		v18 - v19
End of changes. 109 change blocks.
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