NETCONF E. Voit
Internet-Draft Cisco Systems
Intended status: Standards Track H. Birkholz
Expires: August 24, 2018 Fraunhofer SIT
A. Bierman
YumaWorks
A. Clemm
Huawei
T. Jenkins
Cisco Systems
February 20, 2018
Notification Message Headers and Bundles
draft-ietf-netconf-notification-messages-03
Abstract
This document defines a new notification message format, using yang-
data. Included are:
o a new notification mechanism and encoding to replace the one way
operation of RFC-5277
o a set of common, transport agnostic message header objects.
o how to bundle multiple event records into a single notification
message.
o how to ensure these new capabilities are only used with capable
receivers.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 24, 2018.
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Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Header Objects . . . . . . . . . . . . . . . . . . . . . . . 3
4. Encapsulation of Header Objects in Messages . . . . . . . . . 4
4.1. One Notification per Message . . . . . . . . . . . . . . 5
4.2. Many Notifications per Message . . . . . . . . . . . . . 5
5. Configuration of Headers . . . . . . . . . . . . . . . . . . 8
6. Discovering Receiver Support . . . . . . . . . . . . . . . . 9
7. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 10
8. Backwards Compatibility . . . . . . . . . . . . . . . . . . . 18
9. Security Considerations . . . . . . . . . . . . . . . . . . . 18
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 19
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.1. Normative References . . . . . . . . . . . . . . . . . . 19
11.2. Informative References . . . . . . . . . . . . . . . . . 19
Appendix A. Changes between revisions . . . . . . . . . . . . . 20
Appendix B. Issues being worked . . . . . . . . . . . . . . . . 21
Appendix C. Subscription Specific Headers . . . . . . . . . . . 21
Appendix D. Implications to Existing RFCs . . . . . . . . . . . 22
D.1. Implications to RFC-7950 . . . . . . . . . . . . . . . . 22
D.2. Implications to RFC-8040 . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction
Mechanisms to support subscription to event notifications and yang
datastore push are being defined in
[I-D.draft-ietf-netconf-subscribed-notifications] and
[I-D.ietf-netconf-yang-push]. Work on those documents has shown that
notifications described in [RFC7950] section 7.16 could benefit from
transport independent headers. Communicating the following
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information to receiving applications can be done without explicit
linkage to an underlying transport protocol:
o the time information was generated
o the time the information was placed in a message and queued for
transport
o a signature to verify authenticity
o the process generating the information
o an originating request correlation
o an ability to bundle information records into one a message
o the ability to check for message loss/reordering
The document describes information elements needed for the functions
above. It also provides YANG structures for sending messages
containing one or more events and/or update records to a receiver.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
The definition of notification is in RFC 7950 [RFC7950]. Publisher,
receiver, and subscription are defined in
[I-D.draft-ietf-netconf-subscribed-notifications].
3. Header Objects
There are a number of transport independent headers which should have
common definition. These include:
o subscription-id: provides a reference into the reason the
publisher believed the receiver wishes to be notified of this
specific information.
o notification-time: the time an event, datastore update, or other
item is recognized and recorded within the publisher.
o notification-id: Identifies the name of the notification, per the
YANG notification statement. May also provide the name of a yang-
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data statement (whether transporting other types of messages is in
scope is tbd).
o observation-domain-id: identifies the publisher process which
discovered and recorded the event notification. (note: look to
reuse the domains set up with IPFIX.)
o message-time: the time the message was packaged sent to the
transport layer for delivery to the receiver.
o signature: allows an application to sign a message so that a
receiver can verify the authenticity of the message.
o message-id: for a specific message generator, this identifies a
message which includes one or more event records. The message-id
increments by one with sequential messages.
o message-generator-id: identifier for the process which created the
message. This allows disambiguation of an information source,
such as the identification of different line cards sending the
messages. Used in conjunction with previous-message-id, this can
help find drops and duplications when messages are coming from
multiple sources on a device. If there is a message-generator-id
in the header, then the previous-message-id MUST be the message-id
from the last time that message-generator-id was sent.
4. Encapsulation of Header Objects in Messages
A specific set of well-known objects are of potential use to
networking layers prior being interpreted by some receiving
application layer process. By exposing this object information as
part of a header, and by using standardized object names, it becomes
possible for this object information to be leveraged in transit.
The objects defined in the previous section are these well-known
header objects. These objects are identified within a dedicated
header subtree which leads off a particular transportable message.
This allows header objects to be easily be decoupled, stripped, and
processed separately.
There are two types of transportable messages: one format is used
when there is one notification being encapsulated, and another format
used when there are many notifications being bundled into one
message.
A receiver which supporting this document MUST be able to handle
receipt of either type of message from an publisher. It is possible
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that changes between message types can occur without any prior
indication.
4.1. One Notification per Message
This section will be re-instated if NETCONF WG members are not
comfortable with the efficiency of the solution which can encode many
notifications per message described below.
4.2. Many Notifications per Message
While possible in some scenarios, it often inefficient to marshal and
transport every notification independently. Instead, scale and
processing speed can be improved by placing multiple notifications
into one transportable bundle.
The format of this bundle appears in the yata-data tree below, and is
more completely defined in the yang module. There are three parts of
this bundle:
o a message header describing the marshaling, including information
such as when the marshaling occurred
o a list of encapsulated information
o an optional message footer for whole-message signing and message-
generator integrity verification.
Within the list of encapsulated notifications, there are also three
parts:
o a notification header defining what is in an encapsulated
notification
o the actual notification itself
o an optional notification footer for individual notification
signing and observation-domain integrity verification.
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yang-data message
+--ro message!
+--ro message-header
| +--ro message-time yang:date-and-time
| +--ro message-id? uint32
| +--ro message-generator-id? string
| +--ro notification-count? uint16
+--ro notifications*
| +--ro notification-header
| | +--ro notification-time yang:date-and-time
| | +--ro yang-module? yang:yang-identifier
| | +--ro yang-notification-name? notification-type
| | +--ro subscription-id* uint32
| | +--ro notification-id? uint32
| | +--ro observation-domain-id? string
| +--ro notification-contents?
| +--ro notification-footer!
| +--ro signature-algorithm string
| +--ro signature-value string
| +--ro integrity-evidence? string
+--ro message-footer!
+--ro signature-algorithm string
+--ro signature-value string
+--ro integrity-evidence? string
An XML instance of a message might look like:
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<yang-data bundled-message
xmlns="urn:ietf:params:xml:ns:yang:ietf-notification-messages:1.0">
<message-header>
<message-time>
2017-02-14T00:00:05Z
</message-time>
<message-id>
456
</message-id>
<notification-count>
2
</notification-count>
</message-header>
<notifications>
<notification>
<notification-header>
<notification-time>
2017-02-14T00:00:02Z
</notification-time>
<subscription-id>
823472
</subscription-id>
<yang-module>
ietf-yang-push
</yang-module>
<yang-notification-name>
push-change-update
</yang-notification-name>
</notification-header>
<notification-contents>
<push-change-update xmlns=
"urn:ietf:params:xml:ns:yang:ietf-yang-push:1.0">
<datastore-changes-xml>
<alpha xmlns="http://example.com/sample-data/1.0">
<beta urn:ietf:params:xml:ns:netconf:base:1.0:
operation="delete"/>
</alpha>
</datastore-changes-xml>
</push-change-update>
</notification-contents>
</notification>
<notification>
...(record #2)...
</notification>
</notifications>
</yang-data>
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5. Configuration of Headers
A publisher MUST select the set of headers to use within any
particular message. The two mandatory headers which MUST always be
applied are 'message-time' and 'subscription-id'
Beyond these two mandatory headers, additional headers MAY be
included. Configuration of what these optional headers should be can
come from the following sources:
1. Publisher wide default headers for all notifications. These are
included if an optional header is inserted into 'additional-
headers' leaf-list shown in the yang tree below.
2. More notification specific headers may also be desired. If new
headers are needed for a specific type of YANG notification,
these can be populated through 'additional-notification-headers'
leaf-list.
3. An application process may also identify common headers to use
when transporting notifications for a specific subscription. How
these are identified to a publisher is out-of-scope.
The set of headers used for any particular message is the superset of
headers for the items listed above.
The YANG tree showing elements of configuration is depicted in the
following figure.
module: ietf-notification-messages
+--rw additional-default-headers {publisher}?
+--rw additional-headers* optional-header
+--rw yang-notification-specific-default*
| [yang-module yang-notification-name]
+--rw yang-module yang:yang-identifier
+--rw yang-notification-name notification-type
+--rw additional-notification-headers*
optional-notification-header
Configuration Model structure
Of note in this tree is the optional feature of 'publisher'. This
feature indicates an ability to send notifications. A publisher
supporting this specification MUST also be able to parse any messages
received as defined in this document.
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6. Discovering Receiver Support
We need capability exchange from the receiver to the publisher at
transport session initiation to indicate support for this
specification.
For all types of transport connections, if the receiver indicates
support for this specification, then it MAY be used. In addition,
[RFC5277] one-way notifications MUST NOT be used if the receiver
indicates support for this specification to a publisher which also
supports it.
Where NETCONF transport is used, advertising this specification's
namespace during an earlier client capabilities discovery phase MAY
be used to indicate support for this specification:
<hello xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<capabilities>
<capability>
urn:ietf:params:xml:ns:yang:ietf-notification-messages:1.0
</capability>
</capabilities>
<session-id>4</session-id>
</hello>
NOTE: It is understood that even though it is allowed in [RFC6241]
section 8.1, robust NETCONF client driven capabilities exchange is
not something which is common in implementation. Therefore reviewers
are asked to submit alternative proposals to the mailing list.
For RESTCONF, a mechanism for capability discovery is TBD. Proposals
are also welcome here.
The mechanism described above assumes that a capability discovery
phase happens before a subscription is started. This is not always
the case. As an example, consider HTTP2 configured subscriptions
from section 3.1.3 of [I-D.draft-ietf-netconf-restconf-notif], there
is no guarantee that a capability exchange has taken place before the
updates are pushed. A solution for this could be that a receiver
would reply "ok" and reply with the client capabilities as part of
the POST. (Or just use a different HTTP status code like 202 instead
of 200 'ok'). As such a requirement creates a new dependency for
[I-D.draft-ietf-netconf-restconf-notif] upon this specification, more
discussion is required to decide if this is a viable solution.
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7. YANG Module
<CODE BEGINS> file "ietf-notification-messages@2018-01-31.yang"
module ietf-notification-messages {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-notification-messages";
prefix nm;
import ietf-yang-types { prefix yang; }
import ietf-restconf { prefix rc; }
organization "IETF";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Editor: Eric Voit
<mailto:evoit@cisco.com>
Editor: Henk Birkholz
<mailto:henk.birkholz@sit.fraunhofer.de>
Editor: Alexander Clemm
<mailto:ludwig@clemm.org>
Editor: Andy Bierman
<mailto:andy@yumaworks.com>
Editor: Tim Jenkins
<mailto:timjenki@cisco.com>";
description
"This module contains conceptual YANG specifications for yang-data
messages carrying notifications with well known header objects.";
revision 2018-01-31 {
description
"Initial version.";
reference
"draft-ietf-netconf-notification-messages-03";
}
/*
* FEATURES
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*/
feature publisher {
description
"This feature indicates that support for both publisher and
receiver of messages complying to the specification.";
}
/*
* IDENTITIES
*/
/* Identities for common headers */
identity common-header {
description
"A well known header which can be included somewhere within a
message.";
}
identity message-time {
base common-header;
description
"Header information consisting of time the message headers were
placed generated prior to being sent to transport";
}
identity subscription-id {
base common-header;
description
"Header information consisting of the identifier of the
subscription associated with the notification being
encapsulated.";
}
identity notification-count {
base common-header;
description
"Header information consisting of the quantity of notifications in
a bundled-message for a specific receiver.";
}
identity optional-header {
base common-header;
description
"A well known header which an application may choose to include
within a message.";
}
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identity message-id {
base optional-header;
description
"Header information that identifies a message to a specific
receiver";
}
identity message-generator-id {
base optional-header;
description
"Header information consisting of an identifier for a software
entity which created the message (e.g., linecard 1).";
}
identity message-signature {
base optional-header;
description
"Identifies two elements of header information consisting of a
signature and the signtature type for the contents of a message.
Signatures can be useful for originating applications to
verify record contents even when shipping over unsecure
transport.";
}
identity message-integrity-evidence {
base optional-header;
description
"Header information consisting of the information which backs up
the assertions made as to the validity of the information
provided within the message.";
}
identity optional-notification-header {
base optional-header;
description
"A well known header which an application may choose to include
within a message.";
}
identity notification-time {
base optional-notification-header;
description
"Header information consisting of the time an originating process
created the notification.";
}
identity notification-id {
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base optional-notification-header;
description
"Header information consisting of an identifier for an instance
of a notification egressing a publisher. ";
}
identity observation-domain-id {
base optional-notification-header;
description
"Header information identifying the software entity which created
the notification (e.g., process id).";
}
identity notification-signature {
base optional-notification-header;
description
"Header information consisting of the information which backs up
the assertions made as to the validity of the information
provided within the notification.";
}
identity notification-integrity-evidence {
base optional-notification-header;
description
"Header information consisting of the information which backs up
the assertions made as to the validity of the information
provided within the notification.";
}
/*
* TYPEDEFs
*/
typedef optional-header {
type identityref {
base optional-header;
}
description
"Type of header object which may be included somewhere within a
message.";
}
typedef optional-notification-header {
type identityref {
base optional-notification-header;
}
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description
"Type of header object which may be included somewhere within a
message.";
}
typedef notification-type {
type string {
pattern '[a-zA-Z_][a-zA-Z0-9\-_.]*';
}
description
"The name of a notification within a YANG module.";
reference
"RFC-7950 Section 7.16";
}
/*
* GROUPINGS
*/
grouping message-header {
description
"Header information included with a message.";
leaf message-time {
type yang:date-and-time;
mandatory true;
description
"time the message was generated prior to being sent to
transport.";
}
leaf message-id {
type uint32;
description
"Id for a message going to a receiver from a message
generator. The id will increment by one with each message sent
from a particular message generator, allowing the message-id
to be used as a sequence number.";
}
leaf message-generator-id {
type string;
description
"Software entity which created the message (e.g., linecard 1).
The combination of message-id and message-generator-id must be
unique until reset or a roll-over occurs.";
}
leaf notification-count {
type uint16;
description
"Quantity of notification records in a bundled-message
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specific receiver.";
}
}
grouping notification-within-a-module {
description
"A location of a notification within a yang model.";
leaf yang-module {
type yang:yang-identifier;
description
"Name of the YANG module supported by the publisher.";
}
leaf yang-notification-name {
type notification-type;
description
"The name of a notification likely from a YANG module. Note
that this object should be in the notification contents, so a
debate is needed whether this is redundant.";
}
}
grouping notification-header {
description
"Common informational objects which might help a receiver
interpret the meaning, details, or importance of a notification.";
leaf notification-time {
type yang:date-and-time;
mandatory true;
description
"Time the system recognized the occurrence of an event.";
}
uses notification-within-a-module;
leaf-list subscription-id {
type uint32;
description
"Id of the subscription which led to the notification being
generated.";
}
leaf notification-id {
type uint32;
description
"Identifier for the notification record.";
}
leaf observation-domain-id {
type string;
description
"Software entity which created the notification record (e.g.,
process id).";
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}
}
grouping security-footer {
description
"Reusable grouping for common objects which apply to the the
signing of notifications or messages.";
leaf signature-algorithm {
type string;
mandatory true;
description
"The technology with which an originator signed of some
delineated contents.";
}
leaf signature-value {
type string;
mandatory true;
description
"Any originator signing of the contents of a header and
content. This is useful for verifying contents even when
shipping over unsecure transport.";
}
leaf integrity-evidence {
type string;
description
"This mechanism allows a verifier to ensure that the use of the
private key, represented by the corresponding public key
certificate, was performed with a TCG compliant TPM
environment. This evidence is never included in within any
signature.";
reference
"TCG Infrastructure Workgroup, Subject Key Attestation Evidence
Extension, Specification Version 1.0, Revision 7.";
}
}
/*
* YANG-DATA messages for receivers
*/
rc:yang-data message {
container message {
presence
"Indicates attempt to communicate notifications to a receiver.";
description
"Message to a receiver containing one or more notifications";
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container message-header {
description
"Header info for messages.";
uses message-header;
}
list notifications {
description
"Set of notifications to a receiver.";
container notification-header {
description
"Header info for a notification.";
uses notification-header;
}
anydata notification-contents {
description
"Encapsulates objects following YANG's notification-stmt
grammar of RFC-7950 section 14. Within are the notified
objects the publisher actually generated in order to be
passed to a receiver after all filtering has completed.";
}
container notification-footer {
presence
"Indicates attempt to secure a notification.";
description
"Signature and evidence for messages.";
uses security-footer;
}
}
container message-footer {
presence
"Indicates attempt to secure the entire message.";
description
"Signature and evidence for messages.";
uses security-footer;
}
}
}
/*
* DATA-NODES
*/
container additional-default-headers {
if-feature "publisher";
description
"This container maintains a list of which additional notifications
should use which optional headers if the receiver supports this
specification.";
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leaf-list additional-headers {
type optional-header;
description
"This list contains the identities of the optional header types
which are to be included within each message from this
publisher.";
}
list yang-notification-specific-default {
key "yang-module yang-notification-name";
description
"For any included YANG notifications, this list provides
additional optional headers which should be placed within the
container notification-header if the receiver supports this
specification. This list incrementally adds to any headers
indicated within the leaf-list 'additional-headers'.";
uses notification-within-a-module;
leaf-list additional-notification-headers {
type optional-notification-header;
description
"The set of additional default headers which will be sent
for a specific YANG notification.";
}
}
}
}
<CODE ENDS>
8. Backwards Compatibility
With this specification, there is no change to YANG's 'notification'
statement
Legacy clients are unaffected, and existing users of [RFC5277],
[RFC7950], and [RFC8040] are free to use current behaviors until all
involved device support this specification.
9. Security Considerations
Certain headers might be computationally complex for a publisher to
deliver. Signatures or encryption are two examples of this. It MUST
be possible to suspend or terminate a subscription due to lack of
resources based on this reason.
Decisions on whether to bundle or not to a receiver are fully under
the purview of the Publisher. A receiver could slow delivery to
existing subscriptions by creating new ones. (Which would result in
the publisher going into a bundling mode.)
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10. Acknowledgments
For their valuable comments, discussions, and feedback, we wish to
acknowledge Martin Bjorklund, Einar Nilsen-Nygaard, and Kent Watsen.
11. References
11.1. Normative References
[I-D.draft-ietf-netconf-subscribed-notifications]
Voit, E., Clemm, A., Gonzalez Prieto, A., Tripathy, A.,
and E. Nilsen-Nygaard, "Custom Subscription to Event
Streams", draft-ietf-netconf-subscribed-notifications-06
(work in progress), January 2018.
[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>.
[RFC5277] Chisholm, S. and H. Trevino, "NETCONF Event
Notifications", RFC 5277, DOI 10.17487/RFC5277, July 2008,
<https://www.rfc-editor.org/info/rfc5277>.
[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>.
11.2. Informative References
[I-D.draft-ietf-netconf-restconf-notif]
Voit, Eric., Clemm, Alexander., Tripathy, A., Nilsen-
Nygaard, E., and Alberto. Gonzalez Prieto, "Restconf and
HTTP transport for event notifications", January 2018,
<https://datatracker.ietf.org/doc/
draft-ietf-netconf-restconf-notif/>.
[I-D.ietf-netconf-yang-push]
Clemm, Alexander., Voit, Eric., Gonzalez Prieto, Alberto.,
Tripathy, A., Nilsen-Nygaard, E., Bierman, A., and B.
Lengyel, "YANG Datastore Subscription", December 2017,
<https://datatracker.ietf.org/doc/
draft-ietf-netconf-yang-push/>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
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[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
Appendix A. Changes between revisions
(To be removed by RFC editor prior to publication)
v02 - v03
o Removed the option for an unbundled message. This might be re-
added later for transport efficiency if desired by the WG
o New message structure driven by the desire to put the signature
information at the end.
v01 - v02
o Fixed the yang-data encapsulation container issue
o Updated object definitions to point to RFC-7950 definitions
o Added headers for module and notification-type.
v00 - v01
o Alternative to 5277 one-way notification added
o Storage of default headers by notification type
o Backwards compatibility
o Capability discovery
o Move to yang-data
o Removed dscp and record-type as common headers. (Record type can
be determined by the namespace of the record contents. Dscp is
useful where applications need internal communications within a
Publisher, but it is unclear as to whether this use case need be
exposed to a receiver.
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Appendix B. Issues being worked
(To be removed by RFC editor prior to publication)
Is this capability just for notifications, or is it for any yang-data
element too?
A complete JSON document is supposed to be sent as part of Media Type
"application/yang-data+json". As we are sending separate
notifications after each other, we need to choose whether we start
with some extra encapsulation for the very first message pushed, or
if we want a new Media Type for streaming updates.
Improved discovery mechanisms for NETCONF
Should we defer support for HTTP2 configured subscriptions until this
draft is available? Without capabilities exchange, it might just be
easier to wait. In addition, JSON encoding still needs a
notification type which is not exising or represented in
referenceable in existing yang-models.
Need to ensure the proper references exist to a notification
definition driven by RFC-7950 which is acceptable to other eventual
users of this specification.
We need to link to Andy Bierman's anydata extensibility draft for
informational purposes. This is under a WG adoption call.
Appendix C. Subscription Specific Headers
(To be removed by RFC editor prior to publication)
This section discusses a future functional addition which could
leverage this draft. It is included for informational purposes only.
A dynamic subscriber might want to mandate that certain headers be
used for push updates from a publisher. Some examples of this
include a subscriber requesting to:
o establish this subscription, but just if transport messages
containing the pushed data will be encrypted,
o establish this subscription, but only if you can attest to the
information being delivered in requested notification records, or
o provide a sequence-id for all messages to this receiver (in order
to check for loss).
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Providing this type of functionality would necessitate a new revision
of the [I-D.draft-ietf-netconf-subscribed-notifications]'s RPCs and
state change notifications. Subscription specific header information
would overwrite the default headers identified in this document.
Appendix D. Implications to Existing RFCs
(To be removed by RFC editor prior to publication)
YANG one-way exchanges currently use a non-extensible header and
encoding defined in section 4 of RFC-5277. These RFCs MUST be
updated to enable this draft. These RFCs SHOULD be updated to
provide examples
D.1. Implications to RFC-7950
Sections which expose netconf:capability:notification:1.0 are 4.2.10
Sections which provide examples using netconf:notification:1.0 are
7.10.4, 7.16.3, and 9.9.6
D.2. Implications to RFC-8040
Section 6.4 demands use of RFC-5277's netconf:notification:1.0, and
later in the section provides an example.
Authors' Addresses
Eric Voit
Cisco Systems
Email: evoit@cisco.com
Henk Birkholz
Fraunhofer SIT
Email: henk.birkholz@sit.fraunhofer.de
Andy Bierman
YumaWorks
Email: andy@yumaworks.com
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Alexander Clemm
Huawei
Email: ludwig@clemm.org
Tim Jenkins
Cisco Systems
Email: timjenki@cisco.com
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