| Internet-Draft | Data Export Capability | August 2021 |
| Wu, et al. | Expires 3 March 2022 | [Page] |
This document proposes a YANG module for data export notification capabilities which augments System-Capabilities model defined in [I-D.netconf-notification-capabilities] and provides additional data export attributes associated with system capabilities for transport specific Notification. This YANG module can be used by the client to learn capability information from the server at run-time or implementation-time, per the YANG Instance Data File Format.¶
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This Internet-Draft will expire on 3 March 2022.¶
Copyright (c) 2021 IETF Trust and the persons identified as the document authors. All rights reserved.¶
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of 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.¶
Notification capabilities model defined in [I-D.netconf-notification-capabilities] allows a client to discover a set of capabilities supported by the server (e.g., basic system capabilities and YANG-Push related capabilities) both at implementation-time and run-time. These capabilities allow the client to adjust its behavior to take advantage of the features exposed by the server.¶
However the client and the server may still support various different transport specific parameters (e.g., transport protocol, encoding format, encryption). As described in section 3.1 of [RFC8641], a simple negotiation (i.e., inserting hints into error responses to a failed RPC request) between subscribers and publishers for subscription parameters increases the likelihood of success for subsequent RPC requests, but not guaranteed, which may cause unexpected failure or additional message exchange between client and server.¶
This document defines a corresponding solution that is built on top of [I-D.netconf-notification-capabilities]. Supplementing that work are YANG data model augmentations for transport specific notification. The module can be used by the client to discover capability information from the server at run-time or implementation- time, per the YANG Instance Data File Format.¶
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 YANG module ietf-notification-capabilities defined in [I-D.netconf-notification-capabilities] specify the following server capabilities related to YANG Push:¶
These server capabilities are transport independent, session level capabilities. They can be provided either at the implementation time or reported at the run time.¶
This document augments system Capabilities model and provides additional data export attributes associated with system capabilities:¶
The following tree diagram [RFC8340] provides an overview of the data model.¶
module: ietf-data-export-capabilities
augment /sysc:system-capabilities:
+--ro data-export-capabilities
+--ro data-export-capability* []
+--ro transport-protocol? identityref
+--ro encoding-format* identityref
+--ro security-protocol? identityref
+--ro message-bundling-support? empty¶
<CODE BEGINS> file "ietf-data-export-capabilities.yang"
module ietf-data-export-capabilities {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-data-export-capabilities";
prefix dec;
import ietf-system-capabilities {
prefix sysc;
}
import ietf-notification-capabilities {
prefix inc;
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <https://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Editor: Qin Wu <mailto:bill.wu@huawei.com>
Editor: Qiufang Ma <mailto: maqiufang1@huawei.com>
Editor: Peng Liu <mailto: liupengyjy@chinamobile.com>
Editor: Wei Wang <mailto: wangw36@chinatelecom.cn>";
description
"This module defines an extension to System Capability and YANG Push
Notification Capabilities model and provides additional data export
attributes for transport specific notification.
Copyright (c) 2019 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX;
see the RFC itself for full legal notices.";
revision 2020-07-03 {
description
"Initial revision.";
reference
"RFC XXXX: Telemetry Data Export capability";
}
identity transport-protocol {
description
"Base identity for transport protocol type.";
}
identity tcp {
base transport-protocol;
description
"Identity for tcp as transport protocol.";
}
identity udp-notif {
base transport-protocol;
description
"Identity for udp notif as transport protocol.";
reference
"draft-ietf-netconf-udp-notif:UDP-based Transport
for Configured Subscriptions";
}
identity http-notif {
base transport-protocol;
description
"Identity for http notif as transport protocol.";
reference
"draft-ietf-netconf-https-notif: An HTTPS-based
Transport for Configured Subscriptions";
}
identity grpc {
base transport-protocol;
description
"Identity for grpc as transport protocol.";
}
identity security-protocol {
description
"Base identity for security protocol type.";
}
identity tls {
base security-protocol;
description
"Identity for tls security protocol.";
}
identity dtls {
base security-protocol;
description
"Identity for dtls security protocol.";
}
identity ssh {
base security-protocol;
description
"Identity for ssh transport protocol.";
}
identity encoding-format {
description
"Base identity for encoding format type.";
}
identity xml {
base encoding-format;
description
"Identity for xml encoding format.";
}
identity json {
base encoding-format;
description
"Identity for json encoding format.";
}
identity binary {
base encoding-format;
description
"Identity for binary encoding format.";
}
identity cbor {
base binary;
description
"Identity for cbor encoding format.";
}
augment "/sysc:system-capabilities" {
description
"Add system level capability.";
container data-export-capabilities {
description
"Capabilities related to data export notification capabilities negotiation.";
list data-export-capability {
description
"Capability list related to data export notification capabilities negotiation.";
leaf transport-protocol {
type identityref {
base transport-protocol;
}
description
"Type of transport protocol.";
}
leaf-list encoding-format {
type identityref {
base encoding-format;
}
description
"Type of encoding format.";
}
leaf security-protocol {
type identityref {
base security-protocol;
}
description
"Type of secure transport.";
}
leaf message-bundling-support {
type empty;
description
"Enables message bundling support.";
}
}
}
}
}
<CODE ENDS>¶
This document registers a URI in the "IETF XML Registry" [RFC3688]. Following the format in [RFC3688], the following registration has been made:¶
URI:
urn:ietf:params:xml:ns:yang:ietf-data-export-capabilities
Registrant Contact:
The IESG.
XML:
N/A; the requested URI is an XML namespace.¶
This document registers one YANG module in the "YANG Module Names" registry [RFC6020]. Following the format in [RFC6020], the following registration has been made:¶
name:
ietf-data-export-capabilities
namespace:
urn:ietf:params:xml:ns:yang:ietf-data-export-capabilities
prefix:
dec
reference:
RFC XXXX (RFC Ed.: replace XXX with actual RFC number and remove
this note.)¶
The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446].¶
The NETCONF Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content.¶
All protocol-accessible data nodes are read-only and cannot be modified. The data in these modules is not security sensitive. Access control may be configured, to avoid exposing the read-only data.¶
When this data is in file format, data should be protected against modification or unauthorized access using normal file handling mechanisms.¶
Ran Tao Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: taoran20@huawei.com Liang Geng China Mobile 32 Xuanwumen West St, Xicheng District Beijing 10053 Email: gengliang@chinamobile.com Thomas Graf Swisscom Binzring 17 Zuerich 8045 Switzerland Email: thomas.graf@swisscom.com¶
The following instance-data example describes the Data Export Notification capabilities of a hypothetical "acme-router".¶
<?xml version="1.0" encoding="UTF-8"?>
<instance-data-set xmlns=
"urn:ietf:params:xml:ns:yang:ietf-yang-instance-data">
<name>acme-router-notification-capabilities</name>
<content-schema>
<module>ietf-system-capabilities@2020-03-23</module>
<module>ietf-notification-capabilities@2020-03-23</module>
<module>ietf-data-export-capabilities@2020-03-23</module>
</content-schema>
<!-- revision date, contact, etc. -->
<description>Server Capability Discovery</description>
<content-data>
<system-capabilities
xmlns="urn:ietf:params:xml:ns:yang:ietf-system-capabilities"
xmlns:inc="urn:ietf:params:xml:ns:yang:ietf-notification-capabilities"
xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
<data-export-capabilities>
<data-export-capability>
<transport-protocol>http-notif</transport-protocol>
<encoding-format>json</encoding-format>
<encoding-format>xml</encoding-format>
</data-export-capability>
<data-export-capability>
<transport-protocol>udp-notif</transport-protocol>
<encoding-format>binary</encoding-format>
</data-export-capability>
</data-export-capabilities>
</system-capabilities>
</content-data>
</instance-data-set>¶
In addition, the client could also query data export capability from the server. For example, the client sends <get> request message to the the server to query data export capability from the server.¶
<rpc message-id="101" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<get>
<filter type="subtree">
<system-capabilities xmlns="urn:ietf:params:xml:ns:yang:ietf-system-capabilities">
<data-export-capabilities/>
</system-capabilities>
</filter>
</get>
</rpc>¶
The server returns server data export capability using <rpc-reply> as follows:¶
<rpc-reply message-id="101" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<data>
<system-capabilities xmlns="urn:ietf:params:xml:ns:yang:ietf-system-capabilities" xmlns:dec="urn:ietf:params:xml:ns:yang:ietf-data-export-capabilities">
<data-export-capabilities>
<data-export-capability>
<transport-protocol>http-notif</transport-protocol>
<encoding-format>json</encoding-format>
</data-export-capability>
<data-export-capability>
<transport-protocol>udp-notif</transport-protocol>
<encoding-format>binary</encoding-format>
</data-export-capability>
</data-export-capabilities>
</system-capabilities>
</data>
</rpc-reply>¶
Since there may be a need for a service to configure both clients and servers with multiple different period intervals and corresponding subscription policy which allows servers/publishers automatically switch to different period intervals according to resource usage change without the interaction with the remote client. E.g., in a wireless network performance monitoring scenario when the wireless signal strength falls below a configured low watermark, the subscribed data can be streamed at a higher rate while when the wireless signal strength crosses a configured high watermark, the subscribed data can be streamed at lower rate.¶
Some per-node capability parameters may be useful in this scenario, which augments system capabilities model(e.g., /sysc:system-capabilities/sysc:datastore-capabilities /sysc:per-node-capabilities) to indicate if the server supports to multiple period intervals switching and counter threshold evaluation. These parameters could be:¶
The "adaptive-interval-support" parameter can be used to report if a server supports to switch to different period intervals automatically when a trigger condition is satisfied. And the counter threshold evaluation could be used for a specific integer built-in type data node when the "counter-threshold-support" parameter is true or present as an empty type.¶
v05-v06¶
v04 - v05¶
v03 - v04¶
v02 - v03¶