< draft-ietf-netconf-restconf-notif-06.txt		draft-ietf-netconf-restconf-notif-07.txt >
	NETCONF E. Voit		NETCONF E. Voit
	Internet-Draft R. Rahman		Internet-Draft R. Rahman
	Intended status: Standards Track E. Nilsen-Nygaard		Intended status: Standards Track E. Nilsen-Nygaard
	Expires: December 20, 2018 Cisco Systems		Expires: March 16, 2019 Cisco Systems
	A. Clemm		A. Clemm
	Huawei		Huawei
	A. Bierman		A. Bierman
	YumaWorks		YumaWorks
	June 18, 2018		September 12, 2018
	RESTCONF and HTTP Transport for Event Notifications		RESTCONF Transport for Event Notifications
	draft-ietf-netconf-restconf-notif-06		draft-ietf-netconf-restconf-notif-07
	Abstract		Abstract
	This document defines RESTCONF, HTTP2, and HTTP1.1 bindings for the		This document defines a RESTCONF binding to the dynamic subscription
	transport of subscription requests and corresponding push updates.		capability of both subscribed notifications and YANG-Push.
	Being subscribed may be either publisher defined event streams or		Subscriptions to publisher defined event streams or nodes/subtrees of
	nodes/subtrees of YANG Datastores.		YANG Datastores is supported.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	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 December 20, 2018.		This Internet-Draft will expire on March 16, 2019.
	Copyright Notice		Copyright Notice
	Copyright (c) 2018 IETF Trust and the persons identified as the		Copyright (c) 2018 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
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3		2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
	3. Dynamic Subscription . . . . . . . . . . . . . . . . . . . . 3		3. Dynamic Subscriptions . . . . . . . . . . . . . . . . . . . . 3
	3.1. Transport Connectivity . . . . . . . . . . . . . . . . . 4		3.1. Transport Connectivity . . . . . . . . . . . . . . . . . 4
	3.2. Discovery . . . . . . . . . . . . . . . . . . . . . . . . 4		3.2. Discovery . . . . . . . . . . . . . . . . . . . . . . . . 4
	3.3. RESTCONF RPCs and HTTP Status Codes . . . . . . . . . . . 4		3.3. RESTCONF RPCs and HTTP Status Codes . . . . . . . . . . . 4
	3.4. Call Flow for HTTP2 . . . . . . . . . . . . . . . . . . . 6		3.4. Call Flow for HTTP2 . . . . . . . . . . . . . . . . . . . 6
	3.5. Call flow for HTTP1.1 . . . . . . . . . . . . . . . . . . 8		3.5. Call flow for HTTP1.1 . . . . . . . . . . . . . . . . . . 8
	4. Configured Subscription . . . . . . . . . . . . . . . . . . . 10		4. QoS Treatment . . . . . . . . . . . . . . . . . . . . . . . . 10
	4.1. Transport Connectivity . . . . . . . . . . . . . . . . . 10		5. Mandatory JSON and datastore support . . . . . . . . . . . . 10
	4.2. Call Flow . . . . . . . . . . . . . . . . . . . . . . . . 11		6. Notification Messages . . . . . . . . . . . . . . . . . . . . 10
	5. QoS Treatment . . . . . . . . . . . . . . . . . . . . . . . . 12		7. YANG Tree . . . . . . . . . . . . . . . . . . . . . . . . . . 10
	6. Mandatory JSON and datastore support . . . . . . . . . . . . 12		8. YANG module . . . . . . . . . . . . . . . . . . . . . . . . . 10
	7. Notification Messages . . . . . . . . . . . . . . . . . . . . 12		9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
	8. YANG Tree . . . . . . . . . . . . . . . . . . . . . . . . . . 12		10. Security Considerations . . . . . . . . . . . . . . . . . . . 13
	9. YANG module . . . . . . . . . . . . . . . . . . . . . . . . . 13		11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13
	10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15		12. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
	11. Security Considerations . . . . . . . . . . . . . . . . . . . 15		12.1. Normative References . . . . . . . . . . . . . . . . . . 14
	12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16		12.2. Informative References . . . . . . . . . . . . . . . . . 15
	13. References . . . . . . . . . . . . . . . . . . . . . . . . . 16		Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 16
	13.1. Normative References . . . . . . . . . . . . . . . . . . 17		A.1. Dynamic Subscriptions . . . . . . . . . . . . . . . . . . 16
	13.2. Informative References . . . . . . . . . . . . . . . . . 18		A.1.1. Establishing Dynamic Subscriptions . . . . . . . . . 16
	Appendix A. RESTCONF over GRPC . . . . . . . . . . . . . . . . . 19		A.1.2. Modifying Dynamic Subscriptions . . . . . . . . . . . 19
	Appendix B. Examples . . . . . . . . . . . . . . . . . . . . . . 19		A.1.3. Deleting Dynamic Subscriptions . . . . . . . . . . . 20
	B.1. Dynamic Subscriptions . . . . . . . . . . . . . . . . . . 19		A.2. Subscription State Notifications . . . . . . . . . . . . 21
	B.1.1. Establishing Dynamic Subscriptions . . . . . . . . . 19		A.2.1. subscription-started and subscription-modified . . . 21
	B.1.2. Modifying Dynamic Subscriptions . . . . . . . . . . . 22		A.2.2. subscription-completed, subscription-resumed, and
	B.1.3. Deleting Dynamic Subscriptions . . . . . . . . . . . 23		replay-complete . . . . . . . . . . . . . . . . . . . 22
	B.2. Configured Subscriptions . . . . . . . . . . . . . . . . 24		A.2.3. subscription-terminated and subscription-suspended . 22
	B.2.1. Creating Configured Subscriptions . . . . . . . . . . 25		Appendix B. Changes between revisions . . . . . . . . . . . . . 23
	B.2.2. Modifying Configured Subscriptions . . . . . . . . . 27		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24
	B.2.3. Deleting Configured Subscriptions . . . . . . . . . . 29
	B.3. Subscription State Notifications . . . . . . . . . . . . 30
	B.3.1. subscription-started and subscription-modified . . . 30
	B.3.2. subscription-completed, subscription-resumed, and
	replay-complete . . . . . . . . . . . . . . . . . . . 31
	B.3.3. subscription-terminated and subscription-suspended . 31
	Appendix C. Changes between revisions . . . . . . . . . . . . . 32
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 33
	1. Introduction		1. Introduction
	Mechanisms to support event subscription and push are defined in		Mechanisms to support event subscription and push are defined in
	[I-D.draft-ietf-netconf-subscribed-notifications]. Enhancements to		[I-D.draft-ietf-netconf-subscribed-notifications]. Enhancements to
	[I-D.draft-ietf-netconf-subscribed-notifications] which enable YANG		[I-D.draft-ietf-netconf-subscribed-notifications] which enable YANG
	datastore subscription and push are defined in		datastore subscription and push are defined in
	[I-D.ietf-netconf-yang-push]. This document provides a transport		[I-D.ietf-netconf-yang-push]. This document provides a transport
	specification for these protocols over RESTCONF [RFC8040] and HTTP.		specification for dynamic subscriptions over RESTCONF [RFC8040].
	Driving these requirements is [RFC7923].		Driving these requirements is [RFC7923].
	The streaming of notifications encapsulating the resulting		The streaming of notifications encapsulating the resulting
	information push can be done with either HTTP1.1 [RFC7231] or HTTP2		information push can be done with either HTTP1.1 [RFC7231] or HTTP2
	[RFC7540].		[RFC7540].
	2. Terminology		2. Terminology
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this		"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
	document are to be interpreted as described in RFC 2119 [RFC2119].		document are to be interpreted as described in RFC 2119 [RFC2119].
	The following terms use the definitions from		The following terms use the definitions from
	[I-D.draft-ietf-netconf-subscribed-notifications]: configured		[I-D.draft-ietf-netconf-subscribed-notifications]: dynamic
	subscription, dynamic subscription, event stream, notification		subscription, event stream, notification message, publisher,
	message, publisher, receiver, subscriber, and subscription.		receiver, subscriber, and subscription.
	Other terms reused include datastore, which is defined in [RFC8342],		Other terms reused include datastore, which is defined in [RFC8342],
	and HTTP2 stream which maps to the definition of "stream" within		and HTTP2 stream which maps to the definition of "stream" within
	[RFC7540], Section 2.		[RFC7540], Section 2.
	[ note to the RFC Editor - please replace XXXX within this document		[ note to the RFC Editor - please replace XXXX within this document
	with the number of this document ]		with the number of this document ]
	3. Dynamic Subscription		3. Dynamic Subscriptions
	This section provides specifics on how to establish and maintain		This section provides specifics on how to establish and maintain
	dynamic subscriptions over HTTP 1.1 and HTTP2 via signaling messages		dynamic subscriptions over HTTP 1.1 and HTTP2 via signaling messages
	transported over RESTCONF [RFC8040]. Subscribing to event streams is		transported over RESTCONF [RFC8040]. Subscribing to event streams is
	accomplished in this way via a RESTCONF POST into RPCs defined within		accomplished in this way via a RESTCONF POST into RPCs defined within
	[I-D.draft-ietf-netconf-subscribed-notifications] Section 2.4. YANG		[I-D.draft-ietf-netconf-subscribed-notifications] Section 2.4. YANG
	datastore subscription is accomplished via augmentations to		datastore subscription is accomplished via augmentations to
	[I-D.draft-ietf-netconf-subscribed-notifications] as described within		[I-D.draft-ietf-netconf-subscribed-notifications] as described within
	[I-D.ietf-netconf-yang-push] Section 4.4.		[I-D.ietf-netconf-yang-push] Section 4.4.
	skipping to change at page 6, line 40 ¶		skipping to change at page 6, line 40 ¶
	3.4. Call Flow for HTTP2		3.4. Call Flow for HTTP2
	Requests to [I-D.draft-ietf-netconf-subscribed-notifications] or		Requests to [I-D.draft-ietf-netconf-subscribed-notifications] or
	[I-D.ietf-netconf-yang-push] augmented RPCs are sent on one or more		[I-D.ietf-netconf-yang-push] augmented RPCs are sent on one or more
	HTTP2 streams indicated by (a) in Figure 1. A successful "establish-		HTTP2 streams indicated by (a) in Figure 1. A successful "establish-
	subscription" will result in an RPC response returned with both a		subscription" will result in an RPC response returned with both a
	subscription identifier which uniquely identifies a subscription, as		subscription identifier which uniquely identifies a subscription, as
	well as a URI which uniquely identifies the location of subscription		well as a URI which uniquely identifies the location of subscription
	on the publisher. This URI is defined via the "uri" leaf the Data		on the publisher. This URI is defined via the "uri" leaf the Data
	Model in Section 9.		Model in Section 8.
	An HTTP POST is then sent on a logically separate HTTP2 stream (b) to		An HTTP POST is then sent on a logically separate HTTP2 stream (b) to
	the URI on the publisher. This initiates to initiate the flow of		the URI on the publisher. This initiates to initiate the flow of
	notification messages which are sent in HTTP Data frames as a		notification messages which are sent in HTTP Data frames as a
	response to the POST. In the case below, a newly established		response to the POST. In the case below, a newly established
	subscription has its associated notification messages pushed over		subscription has its associated notification messages pushed over
	HTTP2 stream (7). These notification messages are placed into a		HTTP2 stream (7). These notification messages are placed into a
	HTTP2 Data frame (see [RFC7540] Section 6.1).		HTTP2 Data frame (see [RFC7540] Section 6.1).
	+------------+ +------------+		+------------+ +------------+
	skipping to change at page 8, line 24 ¶		skipping to change at page 8, line 24 ¶
	3.5. Call flow for HTTP1.1		3.5. Call flow for HTTP1.1
	The call flow is defined in Figure 2. Requests to		The call flow is defined in Figure 2. Requests to
	[I-D.draft-ietf-netconf-subscribed-notifications] or		[I-D.draft-ietf-netconf-subscribed-notifications] or
	[I-D.ietf-netconf-yang-push] augmented RPCs are sent on a TCP		[I-D.ietf-netconf-yang-push] augmented RPCs are sent on a TCP
	connection indicated by (a). A successful "establish-subscription"		connection indicated by (a). A successful "establish-subscription"
	will result in an RPC response returned with both a subscription		will result in an RPC response returned with both a subscription
	identifier which uniquely identifies a subscription, as well as a URI		identifier which uniquely identifies a subscription, as well as a URI
	which uniquely identifies the location of subscription on the		which uniquely identifies the location of subscription on the
	publisher (b). This URI is defined via the "uri" leaf the Data Model		publisher (b). This URI is defined via the "uri" leaf the Data Model
	in Section 9.		in Section 8.
	An HTTP POST is then sent on a logically separate TCP connection (b)		An HTTP POST is then sent on a logically separate TCP connection (b)
	to the URI on the publisher. This initiates to initiate the flow of		to the URI on the publisher. This initiates to initiate the flow of
	notification messages which are sent in SSE [W3C-20150203] as a		notification messages which are sent in SSE [W3C-20150203] as a
	response to the POST.		response to the POST.
	+--------------+ +--------------+		+--------------+ +--------------+
	| Subscriber | | Publisher |		| Subscriber | | Publisher |
	|TCP connection| |TCP connection|		|TCP connection| |TCP connection|
	| (a) (b) | | (a) (b) |		| (a) (b) | | (a) (b) |
	skipping to change at page 10, line 8 ¶		skipping to change at page 10, line 8 ¶
	o In addition to an RPC response for a "modify-subscription" RPC		o In addition to an RPC response for a "modify-subscription" RPC
	traveling over (a), a "subscription-modified" state change		traveling over (a), a "subscription-modified" state change
	notification must be sent within stream (b). This allows the		notification must be sent within stream (b). This allows the
	receiver to know exactly when the new terms of the subscription		receiver to know exactly when the new terms of the subscription
	have been applied to the notification messages. See arrow (c).		have been applied to the notification messages. See arrow (c).
	Open question, should we just eliminate this possibility of HTTP1.1		Open question, should we just eliminate this possibility of HTTP1.1
	for subscriptions? It would make the design simpler.		for subscriptions? It would make the design simpler.
	4. Configured Subscription		4. QoS Treatment
	With a configured subscription, all information needed to establish a
	secure relationship with that receiver is available on the publisher.
	With this information, the publisher will establish a secure
	transport connection with the receiver and then begin pushing
	notification messages to the receiver. Since RESTCONF might not
	exist on the receiver, it is not desirable to require that subscribed
	content be pushed with any dependency on RESTCONF. Therefore in
	place of RESTCONF, an HTTP2 Client connection must be established
	with an HTTP2 Server located on the receiver. Notification messages
	will then be sent as part of an extended HTTP POST to the receiver.
	4.1. Transport Connectivity
	Configured subscriptions MUST only be connected over HTTP2 via a
	client session initiated from the publisher. Following are the
	conditions which MUST be met before establishing a new HTTP2
	connection with a receiver:
	o a configured subscription has a receiver in the connecting state
	as described in [I-D.draft-ietf-netconf-subscribed-notifications],
	section 2.5.1.,
	o the transport configured for that subscription is HTTP2,
	o there are state change notifications or notification messages
	pending for that receiver, and
	o no HTTP2 transport session exists to that receiver,
	If the above conditions are met, then the publisher MUST initiate a
	transport session via RESTCONF call home [RFC8071], section 4.1 to
	that receiver. HTTP2 only communications must be used as per
	[RFC7540], Section 3.3 when the HTTP session over TLS [RFC5246]. and
	[RFC7540], Section 3.4 when transporting cleartext over TCP. Note
	that a subscriber SHOULD establish over TLS in order to secure the
	content in transit.
	If the RESTCONF call home fails because the publisher receives
	receiver credentials which are subsequently declined per [RFC8071],
	Section 4.1, step S5 authentication, then that receiver MUST be
	placed into the timeout state.
	If the call home fails to establish for any other reason, the
	publisher MUST NOT progress the receiver to the active state.
	Additionally, the publisher SHOULD place the receiver into the
	timeout state after a predetermined number of either failed call home
	attempts or remote transport session termination by the receiver.
	4.2. Call Flow
	With HTTP2 connectivity established, a POST of each new
	"subscription-started" state change notification messages will be
	addressed to HTTP augmentation code on the receiver capable of
	accepting and acknowledging to subscription state change
	notifications. Until the "HTTP 200 OK" at point (c) of Figure 3 for
	each the "subscription-started" state change notification, a
	publisher MUST NOT progress the receiver to the active state. In
	other words, is at point (c) which indicates that the receiver is
	ready for the delivery of subscribed content. At this point a
	notification-messages including subscribed content may be placed onto
	an HTTP2 stream for that subscription.
	+------------+ +------------+
	| Receiver | | Publisher |
	|HTTP2 Stream| |HTTP2 Stream|
	| (a) (b) | | (a) (b) |
	+------------+ +------------+
	|HTTP Post Headers, Data (subscription-started)|
	|<---------------------------------------------|
	| HTTP 200 OK |
	|-------------------------------------------->(c)
	| | HTTP Post Headers, Data (notif-message)|
	| |<---------------------------------------------|
	| | HTTP Data (notif-message)|
	| |<---------------------------------------------|
	| | HTTP Data (sub-terminated)|
	| |<---------------------------------------------|
	| |HTTP 200 OK |
	| |--------------------------------------------->|
	Figure 3: Configured over HTTP2
	Additional requirements for configured subscriptions over HTTP2
	include:
	o A unique HTTP2 stream MAY be used for each subscription.
	o A single HTTP2 stream MUST NOT be used for subscriptions with
	different DSCP values.
	o All subscription state notifications from a publisher MUST be
	returned in a separate HTTP Data frame within the HTTP2 stream
	used by the subscription to which the state change refers.
	o An HTTP end of stream message MUST not be sent until all
	subscriptions using that HTTP2 stream have completed.
	5. QoS Treatment
	To meet subscription quality of service promises, the publisher MUST		To meet subscription quality of service promises, the publisher MUST
	take any existing subscription "dscp" and apply it to the DSCP		take any existing subscription "dscp" and apply it to the DSCP
	marking in the IP header.		marking in the IP header.
	In addition, where HTTP2 transport is available to a notification		In addition, where HTTP2 transport is available to a notification
	message queued for transport to a receiver, the publisher MUST:		message queued for transport to a receiver, the publisher MUST:
	o take any existing subscription "priority" and copy it into the		o take any existing subscription "priority" and copy it into the
	HTTP2 stream priority, and		HTTP2 stream priority, and
	o take any existing subscription "dependency" and map the HTTP2		o take any existing subscription "dependency" and map the HTTP2
	stream for the parent subscription into the HTTP2 stream		stream for the parent subscription into the HTTP2 stream
	dependency.		dependency.
	6. Mandatory JSON and datastore support		5. Mandatory JSON and datastore support
	A publisher supporting [I-D.ietf-netconf-yang-push] MUST support the		A publisher supporting [I-D.ietf-netconf-yang-push] MUST support the
	"operational" datastore as defined by [RFC8342].		"operational" datastore as defined by [RFC8342].
	The "encode-json" feature of		The "encode-json" feature of
	[I-D.draft-ietf-netconf-subscribed-notifications] is mandatory to		[I-D.draft-ietf-netconf-subscribed-notifications] is mandatory to
	support. This indicates that JSON is a valid encoding for RPCs,		support. This indicates that JSON is a valid encoding for RPCs,
	state change notifications, and subscribed content.		state change notifications, and subscribed content.
	7. Notification Messages		6. Notification Messages
	Notification messages transported over HTTP will be encoded using		Notification messages transported over HTTP will be encoded using
	one-way operation schema defined within [RFC5277], section 4.		one-way operation schema defined within [RFC5277], section 4.
	8. YANG Tree		7. YANG Tree
	The YANG model defined in Section 9 has one leaf augmented into four		The YANG model defined in Section 8 has one leaf augmented into four
	places of [I-D.draft-ietf-netconf-subscribed-notifications], plus two		places of [I-D.draft-ietf-netconf-subscribed-notifications], plus two
	identities. As the resulting full tree is large, it will only be		identities. As the resulting full tree is large, it will only be
	inserted at later stages of this document.		inserted at later stages of this document.
	9. YANG module		8. YANG module
	This module references		This module references
	[I-D.draft-ietf-netconf-subscribed-notifications].		[I-D.draft-ietf-netconf-subscribed-notifications].
	<CODE BEGINS> file "ietf-http-subscribed-notifications@2018-06-11.yang"		<CODE BEGINS> file "ietf-restconf-subscribed-notifications@2018-09-12.yang"
	module ietf-http-subscribed-notifications {		module ietf-restconf-subscribed-notifications {
	yang-version 1.1;		yang-version 1.1;
	namespace		namespace
	"urn:ietf:params:xml:ns:yang:ietf-http-subscribed-notifications";		"urn:ietf:params:xml:ns:yang:ietf-restconf-subscribed-notifications";
	prefix hsn;
	import ietf-subscribed-notifications {
	prefix sn;
	}
	import ietf-inet-types {
	prefix inet;
	}
	organization "IETF NETCONF (Network Configuration) Working Group";		prefix rsn;
	contact
	"WG Web: <http:/tools.ietf.org/wg/netconf/>
	WG List: <mailto:netconf@ietf.org>
	Editor: Eric Voit		import ietf-subscribed-notifications {
	<mailto:evoit@cisco.com>		prefix sn;
			}
			import ietf-inet-types {
			prefix inet;
			}
	Editor: Alexander Clemm		organization "IETF NETCONF (Network Configuration) Working Group";
	<mailto:ludwig@clemm.org>		contact
			"WG Web: <http:/tools.ietf.org/wg/netconf/>
			WG List: <mailto:netconf@ietf.org>
	Editor: Reshad Rahman		Editor: Eric Voit
	<mailto:rrahman@cisco.com>";		<mailto:evoit@cisco.com>
	description		Editor: Alexander Clemm
	"Defines HTTP variants as a supported transports for subscribed		<mailto:ludwig@clemm.org>
	event notifications.
	Copyright (c) 2018 IETF Trust and the persons identified as authors		Editor: Reshad Rahman
	of the code. All rights reserved.		<mailto:rrahman@cisco.com>";
	Redistribution and use in source and binary forms, with or without		description
	modification, is permitted pursuant to, and subject to the license		"Defines RESTCONF as a supported transport for subscribed
	terms contained in, the Simplified BSD License set forth in Section		event notifications.
	4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info).
	This version of this YANG module is part of RFC XXXX; see the RFC		Copyright (c) 2018 IETF Trust and the persons identified as authors
	itself for full legal notices.";		of the code. All rights reserved.
	revision 2018-06-11 {		Redistribution and use in source and binary forms, with or without
	description		modification, is permitted pursuant to, and subject to the license
	"Initial version";		terms contained in, the Simplified BSD License set forth in Section
	reference		4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
	"RFC XXXX: RESTCONF and HTTP Transport for Event Notifications";		(https://trustee.ietf.org/license-info).
	}
	identity http2 {		This version of this YANG module is part of RFC XXXX; see the RFC
	base sn:transport;		itself for full legal notices.";
	base sn:inline-address;
	base sn:configurable-encoding;
	description
	"HTTP2 is used a transport for notification messages and state
	change notifications.";
	}
	identity http1.1 {		revision 2018-09-12 {
	base sn:transport;		description
	base sn:inline-address;		"Initial version";
	base sn:configurable-encoding;		reference
	description		"RFC XXXX: RESTCONF Transport for Event Notifications";
	"HTTP1.1 is used a transport for notification messages and state
	change notifications.";
	}
	grouping uri {		}
	description
	"Provides a reusable description of a URI.";
	leaf uri {
	type inet:uri;
	config false;
	description
	"Location of a subscription specific URI on the publisher.";
	}
	}
	augment "/sn:establish-subscription/sn:output" {		grouping uri {
	description		description
	"This augmentation allows HTTP specific parameters for a		"Provides a reusable description of a URI.";
	response to a publisher's subscription request.";		leaf uri {
	uses uri;		type inet:uri;
	}		config false;
			description
			"Location of a subscription specific URI on the publisher.";
			}
			}
	augment "/sn:subscriptions/sn:subscription" {		augment "/sn:establish-subscription/sn:output" {
	description		description
	"This augmentation allows HTTP specific parameters to be		"This augmentation allows HTTP specific parameters for a
	exposed for a subscription.";		response to a publisher's subscription request.";
	uses uri;		uses uri;
	}		}
	augment "/sn:subscription-started" {		augment "/sn:subscriptions/sn:subscription" {
	description		description
	"This augmentation allows HTTP specific parameters to be included		"This augmentation allows HTTP specific parameters to be
	part of the notification that a subscription has started.";		exposed for a subscription.";
	uses uri;		uses uri;
	}		}
	augment "/sn:subscription-modified" {		augment "/sn:subscription-started" {
	description		description
	"This augmentation allows HTTP specific parameters to be included		"This augmentation allows HTTP specific parameters to be included
	part of the notification that a subscription has been modified.";		part of the notification that a subscription has started.";
	uses uri;		uses uri;
	}		}
	}		augment "/sn:subscription-modified" {
	<CODE ENDS>		description
			"This augmentation allows HTTP specific parameters to be included
			part of the notification that a subscription has been modified.";
			uses uri;
			}
	10. IANA Considerations		}
			<CODE ENDS>
			9. 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-http-subscribed-notifications		URI: urn:ietf:params:xml:ns:yang:ietf-restconf-subscribed-
			notifications
	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.
	This document registers the following YANG module in the "YANG Module		This document registers the following YANG module in the "YANG Module
	Names" registry [RFC6020]:		Names" registry [RFC6020]:
	Name: ietf-http-subscribed-notifications		Name: ietf-restconf-subscribed-notifications
	Namespace: urn:ietf:params:xml:ns:yang:ietf-http-subscribed-		Namespace: urn:ietf:params:xml:ns:yang:ietf-restconf-subscribed-
	notifications		notifications
	Prefix: hsn		Prefix: rsn
	Reference: RFC XXXX: RESTCONF and HTTP Transport for Event		Reference: RFC XXXX: RESTCONF Transport for Event Notifications
	Notifications
	11. Security Considerations		10. 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 transports		that is designed to be accessed via network management transports
	such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF		such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF
	layer is the secure transport layer, and the mandatory-to-implement		layer is the secure transport layer, and the mandatory-to-implement
	secure transport is Secure Shell (SSH) [RFC6242]. The lowest		secure transport is Secure Shell (SSH) [RFC6242]. The lowest
	RESTCONF layer is HTTPS, and the mandatory-to-implement secure		RESTCONF layer is HTTPS, and the mandatory-to-implement secure
	transport is TLS [RFC5246].		transport is TLS [RFC5246].
	The one new data node introduced in this YANG module may be		The one new data node introduced in this YANG module may be
	skipping to change at page 16, line 20 ¶		skipping to change at page 13, line 46 ¶
	or notification) to this data nodes. These are the subtrees and data		or notification) to this data nodes. These are the subtrees and data
	nodes and their sensitivity/vulnerability:		nodes and their sensitivity/vulnerability:
	Container: "/subscriptions"		Container: "/subscriptions"
	o "uri": leaf will show where subscribed resources might be located		o "uri": leaf will show where subscribed resources might be located
	on a publisher. Access control must be set so that only someone		on a publisher. Access control must be set so that only someone
	with proper access permissions, and perhaps even HTTP session has		with proper access permissions, and perhaps even HTTP session has
	the ability to access this resource.		the ability to access this resource.
	One or more publishers of configured subscriptions could be used to		11. Acknowledgments
	overwhelm a receiver which doesn't even support subscriptions. There
	are two protections needing support on a publisher. First,
	notification messages for configured subscriptions MUST only be
	transmittable over encrypted transports. Clients which do not want
	pushed content need only terminate or refuse any transport sessions
	from the publisher. Second, the HTTP transport augmentation on the
	receiver must send an HTTP 200 OK to a subscription started
	notification before the publisher starts streaming any subscribed
	content.
	One or more publishers could overwhelm a receiver which is unable to
	control or handle the volume of Event Notifications received. In
	deployments where this might be a concern, HTTP2 transport such as
	HTTP2) should be selected.
	The NETCONF Authorization Control Model [RFC6536] SHOULD be used to
	control and restrict authorization of subscription configuration.
	12. Acknowledgments
	We wish to acknowledge the helpful contributions, comments, and		We wish to acknowledge the helpful contributions, comments, and
	suggestions that were received from: Ambika Prasad Tripathy, Alberto		suggestions that were received from: Ambika Prasad Tripathy, Alberto
	Gonzalez Prieto, Susan Hares, Tim Jenkins, Balazs Lengyel, Kent		Gonzalez Prieto, Susan Hares, Tim Jenkins, Balazs Lengyel, Kent
	Watsen, Michael Scharf, and Guangying Zheng.		Watsen, Michael Scharf, and Guangying Zheng.
	13. References		12. References
	13.1. Normative References
	[GRPC] "RPC framework that runs over HTTP2", August 2017,		12.1. Normative References
	<https://grpc.io/>.
	[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, "Custom Subscription to Event		and E. Nilsen-Nygaard, "Custom Subscription to Event
	Streams", draft-ietf-netconf-subscribed-notifications-13		Streams", draft-ietf-netconf-subscribed-notifications-13
	(work in progress), April 2018.		(work in progress), April 2018.
	[I-D.ietf-netconf-yang-push]		[I-D.ietf-netconf-yang-push]
	Clemm, A., Voit, E., Gonzalez Prieto, A., Prasad Tripathy,		Clemm, A., Voit, E., Gonzalez Prieto, A., Prasad Tripathy,
	A., Nilsen-Nygaard, E., Bierman, A., and B. Lengyel,		A., Nilsen-Nygaard, E., Bierman, A., and B. Lengyel,
	skipping to change at page 18, line 15 ¶		skipping to change at page 15, line 11 ¶
	[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>.
	[RFC6520] Seggelmann, R., Tuexen, M., and M. Williams, "Transport		[RFC6520] Seggelmann, R., Tuexen, M., and M. Williams, "Transport
	Layer Security (TLS) and Datagram Transport Layer Security		Layer Security (TLS) and Datagram Transport Layer Security
	(DTLS) Heartbeat Extension", RFC 6520,		(DTLS) Heartbeat Extension", RFC 6520,
	DOI 10.17487/RFC6520, February 2012,		DOI 10.17487/RFC6520, February 2012,
	<https://www.rfc-editor.org/info/rfc6520>.		<https://www.rfc-editor.org/info/rfc6520>.
	[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
	Protocol (NETCONF) Access Control Model", RFC 6536,
	DOI 10.17487/RFC6536, March 2012,
	<https://www.rfc-editor.org/info/rfc6536>.
	[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer		[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
	Protocol (HTTP/1.1): Message Syntax and Routing",		Protocol (HTTP/1.1): Message Syntax and Routing",
	RFC 7230, DOI 10.17487/RFC7230, June 2014,		RFC 7230, DOI 10.17487/RFC7230, June 2014,
	<https://www.rfc-editor.org/info/rfc7230>.		<https://www.rfc-editor.org/info/rfc7230>.
	[RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext		[RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext
	Transfer Protocol Version 2 (HTTP/2)", RFC 7540,		Transfer Protocol Version 2 (HTTP/2)", RFC 7540,
	DOI 10.17487/RFC7540, May 2015,		DOI 10.17487/RFC7540, May 2015,
	<https://www.rfc-editor.org/info/rfc7540>.		<https://www.rfc-editor.org/info/rfc7540>.
	skipping to change at page 18, line 44 ¶		skipping to change at page 15, line 35 ¶
	[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>.
	[W3C-20150203]		[W3C-20150203]
	"Server-Sent Events, World Wide Web Consortium CR CR-		"Server-Sent Events, World Wide Web Consortium CR CR-
	eventsource-20121211", February 2015,		eventsource-20121211", February 2015,
	<https://www.w3.org/TR/2015/REC-eventsource-20150203/>.		<https://www.w3.org/TR/2015/REC-eventsource-20150203/>.
	13.2. Informative References		12.2. Informative References
	[I-D.draft-ietf-netconf-netconf-event-notifications]		[I-D.draft-ietf-netconf-netconf-event-notifications]
	Clemm, Alexander., Voit, Eric., Gonzalez Prieto, Alberto.,		Clemm, Alexander., Voit, Eric., Gonzalez Prieto, Alberto.,
	Nilsen-Nygaard, E., and A. Tripathy, "NETCONF support for		Nilsen-Nygaard, E., and A. Tripathy, "NETCONF support for
	event notifications", May 2018,		event notifications", May 2018,
	<https://datatracker.ietf.org/doc/		<https://datatracker.ietf.org/doc/
	draft-ietf-netconf-netconf-event-notifications/>.		draft-ietf-netconf-netconf-event-notifications/>.
	[I-D.draft-ietf-netconf-nmda-restconf]		[I-D.draft-ietf-netconf-nmda-restconf]
	Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,		Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
	skipping to change at page 19, line 22 ¶		skipping to change at page 16, line 15 ¶
	[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer		[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
	Protocol (HTTP/1.1): Semantics and Content", RFC 7231,		Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
	DOI 10.17487/RFC7231, June 2014,		DOI 10.17487/RFC7231, June 2014,
	<https://www.rfc-editor.org/info/rfc7231>.		<https://www.rfc-editor.org/info/rfc7231>.
	[RFC7923] Voit, E., Clemm, A., and A. Gonzalez Prieto, "Requirements		[RFC7923] Voit, E., Clemm, A., and A. Gonzalez Prieto, "Requirements
	for Subscription to YANG Datastores", RFC 7923,		for Subscription to YANG Datastores", RFC 7923,
	DOI 10.17487/RFC7923, June 2016,		DOI 10.17487/RFC7923, June 2016,
	<https://www.rfc-editor.org/info/rfc7923>.		<https://www.rfc-editor.org/info/rfc7923>.
	[RFC8071] Watsen, K., "NETCONF Call Home and RESTCONF Call Home",		Appendix A. Examples
	RFC 8071, DOI 10.17487/RFC8071, February 2017,
	<https://www.rfc-editor.org/info/rfc8071>.
	Appendix A. RESTCONF over GRPC
	An initial goal for this document was to support [GRPC] transport
	seamlessly without any mapping or extra layering. However there is
	an incompatibility of RESTCONF and GRPC. RESTCONF uses HTTP GET, and
	GRPC uses HTTP2's POST rather than GET. As GET is used across
	RESTCONF for things like capabilities exchange, a seamless mapping
	depends on specification changes outside the scope of this document.
	If/when GRPC supports GET, or RESTCONF is updated to support POST,
	this should be revisited. It is hoped that the resulting fix will be
	transparent to this document.
	Appendix B. Examples
	This section is non-normative. To allow easy comparison, this		This section is non-normative. To allow easy comparison, this
	section mirrors the functional examples shown with NETCONF over XML		section mirrors the functional examples shown with NETCONF over XML
	within [I-D.draft-ietf-netconf-netconf-event-notifications]. In		within [I-D.draft-ietf-netconf-netconf-event-notifications]. In
	addition, HTTP2 vs HTTP1.1 headers are not shown as the contents of		addition, HTTP2 vs HTTP1.1 headers are not shown as the contents of
	the JSON encoded objects are identical within.		the JSON encoded objects are identical within.
	B.1. Dynamic Subscriptions		A.1. Dynamic Subscriptions
	B.1.1. Establishing Dynamic Subscriptions		A.1.1. Establishing Dynamic Subscriptions
	The following figure shows two successful "establish-subscription"		The following figure shows two successful "establish-subscription"
	RPC requests as per		RPC requests as per
	[I-D.draft-ietf-netconf-subscribed-notifications]. The first request		[I-D.draft-ietf-netconf-subscribed-notifications]. The first request
	is given a subscription identifier of 22, the second, an identifier		is given a subscription identifier of 22, the second, an identifier
	of 23.		of 23.
	+------------+ +-----------+		+------------+ +-----------+
	| Subscriber | | Publisher |		| Subscriber | | Publisher |
	+------------+ +-----------+		+------------+ +-----------+
	skipping to change at page 20, line 35 ¶		skipping to change at page 17, line 33 ¶
	|POST (URI#2) |		|POST (URI#2) |
	|------------------------------>|		|------------------------------>|
	| |		| |
	| |		| |
	| notif-mesg (id#22)|		| notif-mesg (id#22)|
	|<------------------------------|		|<------------------------------|
	| HTTP 200 OK,notif-mesg (id#23)|		| HTTP 200 OK,notif-mesg (id#23)|
	|<------------------------------|		|<------------------------------|
	| |		| |
	Figure 4: Multiple subscriptions over RESTCONF/HTTP		Figure 3: Multiple subscriptions over RESTCONF/HTTP
	To provide examples of the information being transported, example		To provide examples of the information being transported, example
	messages for interactions in Figure 4 are detailed below:		messages for interactions in Figure 3 are detailed below:
	POST /restconf/operations/subscriptions:establish-subscription		POST /restconf/operations/subscriptions:establish-subscription
	{		{
	"ietf-subscribed-notifications:input": {		"ietf-subscribed-notifications:input": {
	"stream": "NETCONF",		"stream": "NETCONF",
	"stream-xpath-filter": "/ex:foo/",		"stream-xpath-filter": "/ex:foo/",
	"dscp": "10"		"dscp": "10"
	}		}
	}		}
	Figure 5: establish-subscription request (a)		Figure 4: establish-subscription request (a)
	As publisher was able to fully satisfy the request, the publisher		As publisher was able to fully satisfy the request, the publisher
	sends the subscription identifier of the accepted subscription, and		sends the subscription identifier of the accepted subscription, and
	the URI:		the URI:
	HTTP status code - 200		HTTP status code - 200
	{		{
	"identifier": "22",		"id": "22",
	"uri": "/subscriptions/22"		"uri": "/subscriptions/22"
	}		}
	Figure 6: establish-subscription success (b)		Figure 5: establish-subscription success (b)
	Upon receipt of the successful response, the subscriber POSTs to the		Upon receipt of the successful response, the subscriber POSTs to the
	provided URI to start the flow of notification messages. When the		provided URI to start the flow of notification messages. When the
	publisher receives this, the subscription is moved to the active		publisher receives this, the subscription is moved to the active
	state (c).		state (c).
	POST /restconf/operations/subscriptions/22		POST /restconf/operations/subscriptions/22
	Figure 7: establish-subscription subsequent POST		Figure 6: establish-subscription subsequent POST
	While not shown in Figure 4, if the publisher had not been able to		While not shown in Figure 3, if the publisher had not been able to
	fully satisfy the request, or subscriber has no authorization to		fully satisfy the request, or subscriber has no authorization to
	establish the subscription, the publisher would have sent an RPC		establish the subscription, the publisher would have sent an RPC
	error response. For instance, if the "dscp" value of 10 asserted by		error response. For instance, if the "dscp" value of 10 asserted by
	the subscriber in Figure 5 proved unacceptable, the publisher may		the subscriber in Figure 4 proved unacceptable, the publisher may
	have returned:		have returned:
	HTTP status code - 406		HTTP status code - 406
	{ "ietf-restconf:errors" : {		{ "ietf-restconf:errors" : {
	"error" : [		"error" : [
	{		{
	"error-type": "application",		"error-type": "application",
	"error-tag": "operation-failed",		"error-tag": "operation-failed",
	"error-severity": "error",		"error-severity": "error",
	"error-app-tag":		"error-app-tag":
	"ietf-subscribed-notifications:dscp-unavailable"		"ietf-subscribed-notifications:dscp-unavailable"
	}		}
	]		]
	}		}
	}		}
	Figure 8: an unsuccessful establish subscription		Figure 7: an unsuccessful establish subscription
	The subscriber can use this information in future attempts to		The subscriber can use this information in future attempts to
	establish a subscription.		establish a subscription.
	B.1.2. Modifying Dynamic Subscriptions		A.1.2. Modifying Dynamic Subscriptions
	An existing subscription may be modified. The following exchange		An existing subscription may be modified. The following exchange
	shows a negotiation of such a modification via several exchanges		shows a negotiation of such a modification via several exchanges
	between a subscriber and a publisher. This negotiation consists of a		between a subscriber and a publisher. This negotiation consists of a
	failed RPC modification request/response, followed by a successful		failed RPC modification request/response, followed by a successful
	one.		one.
	+------------+ +-----------+		+------------+ +-----------+
	| Subscriber | | Publisher |		| Subscriber | | Publisher |
	+------------+ +-----------+		+------------+ +-----------+
	skipping to change at page 22, line 37 ¶		skipping to change at page 19, line 34 ¶
	| |		| |
	|modify-subscription (id#23) |		|modify-subscription (id#23) |
	|----------------------------->|		|----------------------------->|
	| HTTP 200 OK |		| HTTP 200 OK |
	|<-----------------------------|		|<-----------------------------|
	| |		| |
	| notif-mesg (id#23)|		| notif-mesg (id#23)|
	|<-----------------------------|		|<-----------------------------|
	| |		| |
	Figure 9: Interaction model for successful subscription modification		Figure 8: Interaction model for successful subscription modification
	If the subscription being modified in Figure 9 is a datastore		If the subscription being modified in Figure 8 is a datastore
	subscription as per [I-D.ietf-netconf-yang-push], the modification		subscription as per [I-D.ietf-netconf-yang-push], the modification
	request made in (d) may look like that shown in Figure 10. As can be		request made in (d) may look like that shown in Figure 9. As can be
	seen, the modifications being attempted are the application of a new		seen, the modifications being attempted are the application of a new
	xpath filter as well as the setting of a new periodic time interval.		xpath filter as well as the setting of a new periodic time interval.
	POST /restconf/operations/subscriptions:modify-subscription		POST /restconf/operations/subscriptions:modify-subscription
	{		{
	"ietf-subscribed-notifications:input": {		"ietf-subscribed-notifications:input": {
	"identifier": "23",		"id": "23",
	"ietf-yang-push:datastore-xpath-filter":		"ietf-yang-push:datastore-xpath-filter":
	"/interfaces-state/interface/oper-status"		"/interfaces-state/interface/oper-status"
	"ietf-yang-push:periodic": {		"ietf-yang-push:periodic": {
	"ietf-yang-push:period": "500"		"ietf-yang-push:period": "500"
	}		}
	}		}
	}		}
	Figure 10: Subscription modification request (c)		Figure 9: Subscription modification request (c)
	If the publisher can satisfy both changes, the publisher sends a		If the publisher can satisfy both changes, the publisher sends a
	positive result for the RPC. If the publisher cannot satisfy either		positive result for the RPC. If the publisher cannot satisfy either
	of the proposed changes, the publisher sends an RPC error response		of the proposed changes, the publisher sends an RPC error response
	(e). The following is an example RPC error response for (e) which		(e). The following is an example RPC error response for (e) which
	includes a hint. This hint is an alternative time period value which		includes a hint. This hint is an alternative time period value which
	might have resulted in a successful modification:		might have resulted in a successful modification:
	HTTP status code - 406		HTTP status code - 406
	skipping to change at page 23, line 45 ¶		skipping to change at page 20, line 45 ¶
	"error-info": {		"error-info": {
	"ietf-yang-push":		"ietf-yang-push":
	"modify-subscription-datastore-error-info": {		"modify-subscription-datastore-error-info": {
	"period-hint": "3000"		"period-hint": "3000"
	}		}
	}		}
	]		]
	}		}
	}		}
	Figure 11: Modify subscription failure with Hint (e)		Figure 10: Modify subscription failure with Hint (e)
	B.1.3. Deleting Dynamic Subscriptions		A.1.3. Deleting Dynamic Subscriptions
	The following demonstrates deleting a subscription. This		The following demonstrates deleting a subscription. This
	subscription may have been to either a stream or a datastore.		subscription may have been to either a stream or a datastore.
	POST /restconf/operations/subscriptions:delete-subscription		POST /restconf/operations/subscriptions:delete-subscription
	{		{
	"delete-subscription": {		"delete-subscription": {
	"identifier": "22"		"id": "22"
	}		}
	}		}
	Figure 12: Delete subscription		Figure 11: Delete subscription
	If the publisher can satisfy the request, the publisher replies with		If the publisher can satisfy the request, the publisher replies with
	success to the RPC request.		success to the RPC request.
	If the publisher cannot satisfy the request, the publisher sends an		If the publisher cannot satisfy the request, the publisher sends an
	error-rpc element indicating the modification didn't work. Figure 13		error-rpc element indicating the modification didn't work. Figure 12
	shows a valid response for existing valid subscription identifier,		shows a valid response for existing valid subscription identifier,
	but that subscription identifier was created on a different transport		but that subscription identifier was created on a different transport
	session:		session:
	HTTP status code - 406		HTTP status code - 406
	{		{
	"ietf-restconf:errors" : {		"ietf-restconf:errors" : {
	"error" : [		"error" : [
	"error-type": "application",		"error-type": "application",
	"error-tag": "operation-failed",		"error-tag": "operation-failed",
	"error-severity": "error",		"error-severity": "error",
	"error-app-tag":		"error-app-tag":
	"ietf-subscribed-notifications:no-such-subscription"		"ietf-subscribed-notifications:no-such-subscription"
	]		]
	}		}
	}		}
	Figure 13: Unsuccessful delete subscription		Figure 12: Unsuccessful delete subscription
	B.2. Configured Subscriptions
	Configured subscriptions may be established, modified, and deleted
	using configuration operations against the top-level subtree of
	[I-D.draft-ietf-netconf-subscribed-notifications] or
	[I-D.ietf-netconf-yang-push].
	In this section, we present examples of how to manage the
	configuration subscriptions using a HTTP2 client.
	B.2.1. Creating Configured Subscriptions
	For subscription creation via configuration operations, a RESTCONF
	client may send:
	POST /restconf/operations/subscriptions/
	{
	"edit-config": {
	"target": {
	"running": null
	},
	"default-operation": "none",
	"config": {
	"subscriptions": {
	"subscription": {
	"identifier": "22",
	"transport": "HTTP2",
	"stream": "NETCONF",
	"receivers": {
	"receiver": {
	"name": "receiver1",
	"address": "1.2.3.4"
	}
	}
	}
	}
	}
	}
	}
	Figure 14: Create a configured subscription
	If the request is accepted, the publisher will indicate this. If the
	request is not accepted because the publisher cannot serve it, no
	configuration is changed. In this case the publisher may reply:
	HTTP status code - 406
	{
	"ietf-restconf:errors" : {
	"error" : [
	"error-type": "application",
	"error-tag": "resource-denied",
	"error-severity": "error",
	"error-message": {
	"@lang": "en",
	"#text": "Temporarily the publisher cannot serve this
	subscription due to the current workload."
	}
	]
	}
	}
	Figure 15: Response to a failed configured subscription establishment
	After a subscription has been created and been verified as VALID,
	HTTP2 connectivity to each receiver will be established if that
	connectivity does not already exist.
	The following figure shows the interaction model for the successful
	creation of a configured subscription.
	+----------+ +-----------+ +---------+
	|Config Ops| | Publisher | | 1.2.3.4 |
	+----------+ +-----------+ +---------+
	| | |
	| Capability Exchange | |
	|<-------------------------->| |
	| | |
	| | |
	| Edit-config | |
	|--------------------------->| |
	| RPC Reply: OK | |
	|<---------------------------| |
	| | Call Home |
	| |<-------------->|
	| | |
	| | subscription- |
	| | started |
	| |--------------->|
	| | |
	| | notification |
	| | message |
	| |--------------->|
	Figure 16: Interaction model for configured subscription
	establishment
	B.2.2. Modifying Configured Subscriptions
	Configured subscriptions can be modified using configuration
	operations against the top-level container "/subscriptions".
	For example, the subscription established in the previous section
	could be modified as follows, here a adding a second receiver:
	POST /restconf/operations/subscriptions
	{
	"edit-config": {
	"target": {
	"running": null
	},
	"config": {
	"subscriptions": {
	"subscription": {
	"identifier": "1922",
	"receivers": {
	"receiver": {
	"name": "receiver2",
	"address": "1.2.3.5"
	}
	}
	}
	}
	}
	}
	}
	Figure 17: Modify configured subscription
	If the request is accepted, the publisher will indicate success. The
	result is that the interaction model described in Figure 16 may be
	extended as follows.
	+----------+ +-----------+ +---------+ +---------+
	|Config Ops| | Publisher | | 1.2.3.4 | | 1.2.3.5 |
	+----------+ +-----------+ +---------+ +---------+
	| | notification | |
	| | message | |
	| |--------------->| |
	| Edit-config | | |
	|--------------------------->| | |
	| RPC Reply: OK | | |
	|<---------------------------| | |
	| | subscription- | |
	| | started | |
	| |---------------------------->|
	| | | |
	| | notification | |
	| | message | |
	| |--------------->| |
	| |---------------------------->|
	| | | |
	Figure 18: Interaction model for configured subscription modification
	Note in the above that in the specific example above, modifying a
	configured subscription actually resulted in "subscription-started"
	notification. And because of existing HTTP2 connectivity, no
	additional call home was needed. Also note that if the edit of the
	configuration had impacted the filter, a separate modify-subscription
	would have been required for the original receiver.
	B.2.3. Deleting Configured Subscriptions
	Configured subscriptions can be deleted using configuration
	operations against the top-level container "/subscriptions".
	Deleting the subscription above would result in the following flow
	impacting all active receivers.
	+----------+ +-----------+ +---------+ +---------+
	|Config Ops| | Publisher | | 1.2.3.4 | | 1.2.3.5 |
	+----------+ +-----------+ +---------+ +---------+
	| | | |
	| | notification | |
	| | message | |
	| |--------------->| |
	| |---------------------------->|
	| | | |
	| Edit-config | | |
	|--------------------------->| | |
	| RPC Reply: OK | | |
	|<---------------------------| | |
	| | subscription- | |
	| | terminated | |
	| |--------------->| |
	| |---------------------------->|
	| | | |
	Figure 19: Interaction model for configured subscription deletion
	B.3. Subscription State Notifications		A.2. Subscription State Notifications
	A publisher will send subscription state notifications according to		A publisher will send subscription state notifications according to
	the definitions within		the definitions within
	[I-D.draft-ietf-netconf-subscribed-notifications]).		[I-D.draft-ietf-netconf-subscribed-notifications]).
	B.3.1. subscription-started and subscription-modified		A.2.1. subscription-started and subscription-modified
	A "subscription-started" encoded in JSON would look like:		A "subscription-started" encoded in JSON would look like:
	{		{
	"ietf-restconf:notification" : {		"ietf-restconf:notification" : {
	"eventTime": "2007-09-01T10:00:00Z",		"eventTime": "2007-09-01T10:00:00Z",
	"ietf-subscribed-notifications:subscription-started": {		"ietf-subscribed-notifications:subscription-started": {
	"identifier": "39",		"id": "39",
	"transport": "HTTP2",		"transport": "HTTP2",
	"stream-xpath-filter": "/ex:foo",		"stream-xpath-filter": "/ex:foo",
	"stream": {		"stream": {
	"ietf-netconf-subscribed-notifications" : "NETCONF"		"ietf-netconf-subscribed-notifications" : "NETCONF"
	}		}
	}		}
	}		}
	}		}
	Figure 20: subscription-started subscription state notification		Figure 13: subscription-started subscription state notification
	The "subscription-modified" is identical to Figure 20, with just the		The "subscription-modified" is identical to Figure 13, with just the
	word "started" being replaced by "modified".		word "started" being replaced by "modified".
	B.3.2. subscription-completed, subscription-resumed, and replay-		A.2.2. subscription-completed, subscription-resumed, and replay-
	complete		complete
	A "subscription-completed" would look like:		A "subscription-completed" would look like:
	{		{
	"ietf-restconf:notification" : {		"ietf-restconf:notification" : {
	"eventTime": "2007-09-01T10:00:00Z",		"eventTime": "2007-09-01T10:00:00Z",
	"ietf-subscribed-notifications:subscription-completed": {		"ietf-subscribed-notifications:subscription-completed": {
	"identifier": "39",		"id": "39",
	}		}
	}		}
	}		}
	Figure 21: subscription-completed notification in JSON		Figure 14: subscription-completed notification in JSON
	The "subscription-resumed" and "replay-complete" are virtually		The "subscription-resumed" and "replay-complete" are virtually
	identical, with "subscription-completed" simply being replaced by		identical, with "subscription-completed" simply being replaced by
	"subscription-resumed" and "replay-complete".		"subscription-resumed" and "replay-complete".
	B.3.3. subscription-terminated and subscription-suspended		A.2.3. subscription-terminated and subscription-suspended
	A "subscription-terminated" would look like:		A "subscription-terminated" would look like:
	{		{
	"ietf-restconf:notification" : {		"ietf-restconf:notification" : {
	"eventTime": "2007-09-01T10:00:00Z",		"eventTime": "2007-09-01T10:00:00Z",
	"ietf-subscribed-notifications:subscription-terminated": {		"ietf-subscribed-notifications:subscription-terminated": {
	"identifier": "39",		"id": "39",
	"error-id": "suspension-timeout"		"error-id": "suspension-timeout"
	}		}
	}		}
	}		}
	Figure 22: subscription-terminated subscription state notification		Figure 15: subscription-terminated subscription state notification
	The "subscription-suspended" is virtually identical, with		The "subscription-suspended" is virtually identical, with
	"subscription-terminated" simply being replaced by "subscription-		"subscription-terminated" simply being replaced by "subscription-
	suspended".		suspended".
	Appendix C. 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)
			v06 - v07
			o Removed configured subscriptions.
			o Subscription identifier renamed to id.
	v05 - v06		v05 - v06
	o JSON examples updated by Reshad.		o JSON examples updated by Reshad.
	v04 - v05		v04 - v05
	o Error mechanisms updated to match embedded RESTCONF mechanisms		o Error mechanisms updated to match embedded RESTCONF mechanisms
	o Restructured format and sections of document.		o Restructured format and sections of document.
End of changes. 84 change blocks.
	531 lines changed or deleted		177 lines changed or added
This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/