NETCONF Working Group Q. Wu Internet-Draft W. Song Intended status: Standards Track Huawei Expires: January 13, 2021 L. Geng P. Liu China Mobile July 12, 2020 Adaptive Subscription to YANG Notification draft-wang-netconf-adaptive-subscription-01 Abstract This document defines a YANG data model and associated mechanism enabling subscriber's adaptive subscriptions to a publisher's event streams at various different period intervals with which to report updates. Applying these elements allows both subscriber and publisher to automatically adjust the volume of telemetry traffic sent from publisher to the 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 January 13, 2021. Copyright Notice Copyright (c) 2020 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 Wu, et al. Expires January 13, 2021 [Page 1] Internet-Draft Adaptive Subscription July 2020 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 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. Model Overview . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Subscription Configuration . . . . . . . . . . . . . . . 5 2.2. YANG RPC . . . . . . . . . . . . . . . . . . . . . . . . 6 2.2.1. "establish-subscription" RPC . . . . . . . . . . . . 6 2.2.2. "modify-subscription" RPC . . . . . . . . . . . . . . 6 2.3. Notifications for Adaptive Subscribed Content . . . . . . 7 3. Adaptive Subscription YANG Module . . . . . . . . . . . . . . 7 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 4.1. Updates to the IETF XML Registry . . . . . . . . . . . . 12 4.2. Updates to the YANG Module Names Registry . . . . . . . . 13 5. Security Considerations . . . . . . . . . . . . . . . . . . . 13 6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 14 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 7.1. Normative References . . . . . . . . . . . . . . . . . . 14 7.2. Informative References . . . . . . . . . . . . . . . . . 15 Appendix A. Example YANG Module . . . . . . . . . . . . . . . . 15 A.1. "example-wifi-mac" YANG Module . . . . . . . . . . . . . 16 Appendix B. Adaptive Subscription and Notification Example . . . 19 B.1. "edit-config" Example . . . . . . . . . . . . . . . . . . 19 B.2. Create Adaptive Subscription Example . . . . . . . . . . 20 B.3. "adaptive-update" notification example . . . . . . . . . 22 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23 1. Introduction YANG-Push subscriptions [RFC8641] allow client applications to subscribe to continuous datastore updates without needing to poll. It defines a mechanism (i.e.,update trigger) to determine when an update record needs to be generated. Two type of subscriptions are introduced in [RFC8641], distinguished by how updates are triggered: periodic and on-change. o Periodic subscription allows subscribed data to be streamed to the destination at a configured fixed periodic interval o On-change subscription allows update to be triggered when whenever a change in the subscribed information is detected. The periodic interval is set to zero value in the on-change subscription case. Wu, et al. Expires January 13, 2021 [Page 2] Internet-Draft Adaptive Subscription July 2020 However in some large scale deployments (e.g., wireless network performance monitoring) where an increased data collection rate is being used, it becomes more likely that a burst of streamed data may temporarily overwhelm a receiver and consume expensive network resource(e.g., air interface resource). If the rate at which we can collect a stream of data is set too low, these telemetry data are not sufficient to detect and diagnose problems and verify correct network behavior. There is a need for a service to configure both collectors and publishers with multiple period intervals, counter threshold and automatically switch to different period intervals according to resource usage, e.g., 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. This document defines a YANG data model and associated mechanism enabling subscriber's adaptive subscriptions to a publisher's event streams. Applying these elements allows both subscriber and publisher to automatically adjust the volume of telemetry traffic sent from publisher to the receivers. 1.1. 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. This document uses the following terms: Event: An event is something that happens that may be of interest - a configuration change, a fault, a change in status, crossing a threshold, or an external input to the system, for example. Often, this results in an asynchronous message, sometimes referred to as a notification or event notification, being sent to interested parties to notify them that this event has occurred [RFC5277]. Client: Defined in [RFC8342]. Configuration: Defined in [RFC8342]. Configured subscription: Defined in [RFC8639] Configuration datastore: Defined in [RFC8342]. Wu, et al. Expires January 13, 2021 [Page 3] Internet-Draft Adaptive Subscription July 2020 Notification message: Information intended for a receiver indicating that one or more events have occurred [RFC8639]. Publisher: An entity responsible for streaming notification messages per the terms of a subscription [RFC8639]. Receiver: A target to which a publisher pushes subscribed event records. For dynamic subscriptions, the receiver and subscriber are the same entity [RFC8639]. Subscriber: A client able to request and negotiate a contract for the generation and push of event records from a publisher. For dynamic subscriptions, the receiver and subscriber are the same entity [RFC8639]. Subscription: A contract with a publisher, stipulating the information that one or more receivers wish to have pushed from the publisher without the need for further solicitation [RFC8639]. On-change subscription: A datastore subscription with updates that are triggered when changes in subscribed datastore nodes are detected. Periodic subscription: A datastore subscription with updates that are triggered periodically according to some time interval. 2. Model Overview This document defines the YANG module "ietf-adaptive-subscription", which augments the "update-trigger" choice defined in the "ietf-yang- push" module [RFC8641] with subscription configuration parameters that are specific to adaptive subscription. In addition to Subscription state notifications defined in [RFC8639] and Notifications for Subscribed Content defined in [RFC8641], "ietf- adaptive-subscription" YANG module also defines "adaptive-update" notification. The following tree diagrams [RFC8340] provide an overview of the data model for "ietf-adaptive-subscription.yang" module. Wu, et al. Expires January 13, 2021 [Page 4] Internet-Draft Adaptive Subscription July 2020 module: ietf-adaptive-subscription augment /sn:subscriptions/sn:subscription/yp:update-trigger: +--rw (adaptive-subscription)? +--:(adaptive-subscriptions) +--rw adaptive-subscriptions +--rw data-path? yang:xpath1.0 +--rw target? +--rw adaptive-period* [condition-expression] +--rw condition-expression string +--rw watermark? uint32 +--rw period centiseconds +--rw count? uint16 +--rw anchor-time? yang:date-and-time augment /sn:establish-subscription/sn:input/yp:update-trigger: +-- (adaptive-subscription)? +--:(adaptive-subscriptions) +-- adaptive-subscriptions +-- data-path? yang:xpath1.0 +-- target? +-- adaptive-period* [condition-expression] +-- condition-expression string +-- watermark? uint32 +-- period centiseconds +-- count? uint16 +-- anchor-time? yang:date-and-time notifications: +---n adaptive-period-update +--ro id? sn:subscription-id +--ro period centiseconds +--ro count? uint16 +--ro anchor-time? yang:date-and-time +--ro datastore identityref +--ro (selection-filter)? +--:(by-reference) | +--ro selection-filter-ref selection-filter-ref +--:(within-subscription) +--ro (filter-spec)? +--:(datastore-subtree-filter) | +--ro datastore-subtree-filter? {sn:subtree}? +--:(datastore-xpath-filter) +--ro datastore-xpath-filter? yang:xpath1.0 {sn:xpath}? 2.1. Subscription Configuration For adaptive subscriptions, triggered updates will occur at the boundaries of specified time intervals when a trigger condition is Wu, et al. Expires January 13, 2021 [Page 5] Internet-Draft Adaptive Subscription July 2020 satisfied. These boundaries can be calculated from the adaptive periodic parameters: o a "period" that defines the duration between push updates, the period can be changed based on trigger condition. o a "count" that specifies the count number of interval that has to pass before successive adaptive periodic push update records for the same subscription are generated for a receiver. o an "anchor-time"; update intervals fall on the points in time that are a multiple of a "period" from an "anchor-time". If an "anchor-time" is not provided, then the "anchor-time" MUST be set with the creation time of the initial update record. o a "high-watermark" that defines the upper boundary for the targeted data object. o a "low-watermark" that defines the lower boundary for the targeted data object. o a "data-path" identifies data path of the targeted data object. o a "data" identifies the targeted data object that has been subscribed to. o a "xpath-expression" represents a logical expression, which can contain comparisons of datastore values and logical operations in the XPath format. 2.2. YANG RPC 2.2.1. "establish-subscription" RPC The augmentation of YANG module ietf-yang-push made to RPCs specified in YANG module ietf-subscribed-notifications [RFC8639] is introduced. This augmentation concerns the "establish- subscription" RPC, which is augmented with parameters that are needed to specify adaptive subscriptions. These parameters are same as one defined in Section 2.1. 2.2.2. "modify-subscription" RPC The subscriber MAY invoke the "modify-subscription" RPC for a subscription it previously established. The subscriber will include newly desired values in the "modify-subscription" RPC. Parameters not included MUST remain unmodified. Section 4.4.2 of [RFC8641] provides an example where a subscriber attempts to modify the period Wu, et al. Expires January 13, 2021 [Page 6] Internet-Draft Adaptive Subscription July 2020 and datastore XPath filter of a subscription using NETCONF. The period can be the 'period' parameter defined by ietf-adaptive- subscription. 2.3. Notifications for Adaptive Subscribed Content The adaptive update notification is similar to Subscription state change notifications defined in [RFC8639]. It is inserted into the sequence of notification messages sent to a particular receiver. The adaptive update notification cannot be dropped or filtered out, it cannot be stored in replay buffers, and it is delivered only to impacted receivers of a subscription. The identification of adaptive update notification is easy to separate from other notification messages through the use of the YANG extension "subscription-state- notif". This extension tags a notification as a subscription state change notification. The objects in the 'adpative-update' notification include: o a "period" that defines the duration between push updates, the period can be changed based on trigger condition. o a "count" that specifies the count number of interval that has to pass before successive adaptive periodic push update records for the same subscription are generated for a receiver. o an "anchor-time"; update intervals fall on the points in time that are a multiple of a "period" from an "anchor-time". If an "anchor-time" is not provided, then the "anchor-time" MUST be set with the creation time of the initial update record. o The targeted datastore from which the selection is being made. The potential datastores include those from [RFC8342]. A platform may also choose to support a custom datastore. o A selection filter identifying YANG nodes of interest in a datastore. Filter contents are specified via a reference to an existing filter or via an in-line definition for only that subscription. Referenced filters allow an implementation to avoid evaluating filter acceptability during a dynamic subscription request. The "case" statement differentiates the options. 3. Adaptive Subscription YANG Module file "ietf-adaptive-subscription@2020-02-14.yang" module ietf-adaptive-subscription { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-adaptive-subscription"; Wu, et al. Expires January 13, 2021 [Page 7] Internet-Draft Adaptive Subscription July 2020 prefix as; import ietf-subscribed-notifications { prefix sn; } import ietf-yang-push { prefix yp; } import ietf-yang-types { prefix yang; } organization "IETF NETCONF (Network Configuration) Working Group"; contact ""; description "NETCONF Protocol Data Types and Protocol Operations. Copyright (c) 2020 IETF Trust and the persons identified as the document authors. 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 2019-12-15 { description "Initial revision"; reference "RFCxxx Adaptive subscription to YANG notification."; } typedef centiseconds { type uint32; description "A period of time, measured in units of 0.01 seconds."; } typedef seconds { type uint32; description "A period of time, measured in units of 1 seconds."; Wu, et al. Expires January 13, 2021 [Page 8] Internet-Draft Adaptive Subscription July 2020 } typedef operator { type enumeration { enum unequal { description "Indicates that the comparision type is unequal to."; } enum equal { description "Indicates that the comparision type is equal to."; } enum less { description "Indicates that the comparision type is less than."; } enum less-or-equal { description "Indicates that the comparision type is less than or equal to."; } enum greater { description "Indicates that the comparision type is greater than."; } enum greater-or-equal { description "Indicates that the comparision type is greater than or equal to."; } } description "definition of the operator"; } grouping adaptive-subscription-modifiable { description "This grouping describes the datastore-specific adaptive subscription conditions that can be changed during the lifetime of the subscription."; choice adaptive-subscription { description "Defines necessary conditions for sending an event record to the subscriber."; container adaptive-subscriptions { leaf data-path { type yang:xpath1.0; description Wu, et al. Expires January 13, 2021 [Page 9] Internet-Draft Adaptive Subscription July 2020 "The data path of targeted object"; } anydata target { description " The targeted data object that has been subscribed to."; } list adaptive-period { key "condition-expression"; description "Defines necessary conditions for sending an event record to the subscriber."; leaf condition-expression { type string; description "A XPath string, representing a logical expression, which can contain comparisons of datastore values and logical operations in the XPath format."; } leaf watermark { type uint32; description "The watermark for targeted data object. The high watermark, lowe watermark can be specified for the targeted data object."; } leaf period { type centiseconds; mandatory true; description "Duration of time that should occur between periodic push updates, in units of 0.01 seconds."; } leaf count { type uint16; description "specify the count number of interval that has to pass before successive adaptive periodic push update records for the same subscription are generated for a receiver."; } leaf anchor-time { type yang:date-and-time; description "Designates a timestamp before or after which a series of periodic push updates are determined. The next update will take place at a point in time that is a multiple of a period from the 'anchor-time'. For example, for an 'anchor-time' that is set for the top of a particular minute and a period interval of a Wu, et al. Expires January 13, 2021 [Page 10] Internet-Draft Adaptive Subscription July 2020 minute, updates will be sent at the top of every minute that this subscription is active."; } } description "Container for adaptive subscription."; } } } augment "/sn:subscriptions/sn:subscription/yp:update-trigger" { description "This augmentation adds additional subscription parameters that apply specifically to adaptive subscription."; uses adaptive-subscription-modifiable; } augment "/sn:establish-subscription/sn:input/yp:update-trigger" { description "This augmentation adds additional subscription parameters that apply specifically to datastore updates to RPC input."; uses adaptive-subscription-modifiable; } notification adaptive-period-update { sn:subscription-state-notification; description "This notification contains a push update that in turn contains data subscribed to via a subscription. In the case of a periodic subscription, this notification is sent for periodic updates. It can also be used for synchronization updates of an on-change subscription. This notification shall only be sent to receivers of a subscription. It does not constitute a general-purpose notification that would be subscribable as part of the NETCONF event stream by any receiver."; leaf id { type sn:subscription-id; description "This references the subscription that drove the notification to be sent."; } leaf period { type centiseconds; mandatory true; description "Duration of time that should occur between periodic push updates, in units of 0.01 seconds."; } leaf count { Wu, et al. Expires January 13, 2021 [Page 11] Internet-Draft Adaptive Subscription July 2020 type uint16; description "specify the count number of interval that has to pass before successive adaptive periodic push update records for the same subscription are generated for a receiver."; } leaf anchor-time { type yang:date-and-time; description "Designates a timestamp before or after which a series of periodic push updates are determined. The next update will take place at a point in time that is a multiple of a period from the 'anchor-time'. For example, for an 'anchor-time' that is set for the top of a particular minute and a period interval of a minute, updates will be sent at the top of every minute that this subscription is active."; } uses yp:datastore-criteria { refine "selection-filter/within-subscription" { description "Specifies the selection filter and where it originated from. If the 'selection-filter-ref' is populated, the filter in the subscription came from the 'filters' container. Otherwise, it is populated in-line as part of the subscription itself."; } } } } 4. IANA Considerations 4.1. Updates to the IETF XML Registry This document registers two URIs in the IETF XML registry [RFC3688]. Following the format in [RFC3688], the following registrations are requested to be made: --------------------------------------------------------------------- URI: urn:ietf:params:xml:ns:yang:ietf-adaptive-subscription Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. --------------------------------------------------------------------- Wu, et al. Expires January 13, 2021 [Page 12] Internet-Draft Adaptive Subscription July 2020 4.2. Updates to the YANG Module Names Registry This document registers two YANG modules in the YANG Module Names registry [RFC7950]. . Following the format in [RFC6020], the following registration has been made: --------------------------------------------------------------------- Name: ietf-adaptive-subscription Namespace: urn:ietf:params:xml:ns:yang:ietf-adaptive-subscription Prefix: as Reference: RFC xxxx --------------------------------------------------------------------- 5. Security Considerations 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. There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability: o /sn:subscriptions/sn:subscription/yp:update-trigger/as:adaptive- subscriptions/as:adaptive-period/as:high-watermark o /sn:subscriptions/sn:subscription/yp:update-trigger/as:adaptive- subscriptions/as:adaptive-period/as:low-watermark o /sn:subscriptions/sn:subscription/yp:update-trigger/as:adaptive- subscriptions/as:adaptive-period/as:period o /sn:subscriptions/sn:subscription/yp:update-trigger/as:adaptive- subscriptions/as:adaptive-period/as:period2 Wu, et al. Expires January 13, 2021 [Page 13] Internet-Draft Adaptive Subscription July 2020 o /sn:subscriptions/sn:subscription/yp:update-trigger/as:adaptive- subscriptions/as:adaptive-period/as:anchor-time o /sn:subscriptions/sn:subscription/yp:update-trigger/as:adaptive- subscriptions/as:adaptive-period/as:anchor-time2 6. Contributors The authors would like to thank Michale Wang for his major contributions to the initial modeling and use cases. 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [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, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Wu, et al. Expires January 13, 2021 [Page 14] Internet-Draft Adaptive Subscription July 2020 [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, . [RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 8407, DOI 10.17487/RFC8407, October 2018, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC8641] Clemm, A. and E. Voit, "Subscription to YANG Notifications for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641, September 2019, . 7.2. Informative References [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . Appendix A. Example YANG Module The example YANG module used in this document represents a simple wifi mac interface. YANG tree diagram for the "example-wifi-mac" module: Wu, et al. Expires January 13, 2021 [Page 15] Internet-Draft Adaptive Subscription July 2020 module: example-wifi-mac +--rw clients +--ro client* [mac] +--ro mac yang:mac-address +--ro rssi? int8 +--ro snr? uint8 +--ro ss? uint8 +--ro phy-rate? uint16 +--ro channel-support* uint8 +--ro neighbors | +--ro neighbor-bssid? yang:mac-address | +--ro neighbor-channel? uint8 | +--ro neighbor-rssi? int8 | +--ro neighbor-antenna? uint8 | +--ro channel-load-report? uint8 +--ro ssid +--ro name? string +--ro enabled? boolean +--ro broadcast-filter? boolean +--ro multicast-filter? boolean +--ro ipv6-ndp-filter? boolean +--ro ipv6-ndp-filter-timer? uint16 +--ro station-isolation? boolean A.1. "example-wifi-mac" YANG Module module example-wifi-mac { yang-version 1; namespace "http://example.com/yang/wifi-mac"; prefix wifi; import ietf-yang-types { prefix yang; } container clients { description "Top-level container for clients operational state data."; list client { key "mac"; config false; description "List of clients per BSS."; leaf mac { type yang:mac-address; description "MAC address of the client."; } Wu, et al. Expires January 13, 2021 [Page 16] Internet-Draft Adaptive Subscription July 2020 leaf rssi { type int8; description "The RSSI of this client in dBm. Expressed as negative number"; } leaf snr { type uint8; description "The SNR of AP to Client, in dB."; } leaf ss { type uint8; description "Number of Spatial Streams supported by the client."; } leaf phy-rate { type uint16; description "Last used PHY rate of connected client."; } leaf-list channel-support { type uint8; description "List of supported channels."; } container neighbors { description "Container for Client beacon reports. Requires 802.11k enabled. See Sec. 5.2.7.1 of 802.11k-2008 Standard."; leaf neighbor-bssid { type yang:mac-address; description "The BSSID of this neighbor."; } leaf neighbor-channel { type uint8; description "The channel of this neighbor."; } leaf neighbor-rssi { type int8; description "The RSSI of this neighbor in dBm, expressed as a negative number."; } leaf neighbor-antenna { type uint8; Wu, et al. Expires January 13, 2021 [Page 17] Internet-Draft Adaptive Subscription July 2020 description "Antenna details for this neighbor."; } leaf channel-load-report { type uint8; description "Channel load, as reported by Client to AP normalized to 255. See Sec. 10.11.9.3 of 802.11ac-2013 Spec."; } } container ssid { description "Top level container for ssids, including configuration and state data."; leaf name { type string; description "The name of the SSID."; } leaf enabled { type boolean; default "true"; description "The desired operational state (up/down) of this SSID."; } leaf broadcast-filter { type boolean; description "Convert all downstream broadcast ARP to unicast only if Station is associated to the AP. Drop packet if Station is not associated to the AP. All other broadcast, except DHCP, is dropped by the AP. DHCP Offers/ACKs are converted to Unicast, over-the-air."; } leaf multicast-filter { type boolean; description "Drop all downstream Multicast packets."; } leaf ipv6-ndp-filter { type boolean; description "Neighbor Advertisements will be cached at the AP (or WLC) and unicast in response to Neighbor Solicitations. Router Advertisements, in response to a Router Solicitation Wu, et al. Expires January 13, 2021 [Page 18] Internet-Draft Adaptive Subscription July 2020 are converted to Unicast for over-the-air transmission."; } leaf ipv6-ndp-filter-timer { type uint16; units "seconds"; description "Time, in seconds, the ndp-filter will cache Neighbor Advertisements (NA)."; } leaf station-isolation { type boolean; description "Block Station peer to peer communication."; } } } } } Appendix B. Adaptive Subscription and Notification Example The examples within this document use the normative YANG module "ietf-adaptive-subscription" as defined in Section 3 and the non- normative example YANG module "example-wifi-mac" as defined in Appendix A.1. This section shows some typical adaptive subscription and notification message exchanges. B.1. "edit-config" Example The client configure adaptive subscription parameters on the server. The adaptive subscription configuration parameters require the server to scan all clients every 5 seconds up to 30 seconds if the ssid value of client is greater than -65dB; If the ssid value of client is less than -65dB, switch to 60 seconds period value, and then scan all client every 60 seconds up to 360 seconds. 30 seconds and 360 seconds can be seen as time window. The time window lenght is 6 period values. Irrespective of period value set for adaptive subscription, 6 event records during the time window should be generated for the same subscription and send to the receivers. Wu, et al. Expires January 13, 2021 [Page 19] Internet-Draft Adaptive Subscription July 2020 ds:running /ex:example-wifi-mac as:clients/as:client ssid ssid > -65 -65 5 12 ssid < -65 -65 60 12 B.2. Create Adaptive Subscription Example The subscriber sends an "establish-subscription" RPC with the parameters listed in to request the creation of a adaptive subscription. The adaptive subscription configuration parameters require the server to scan all clients every 5 seconds up to 60 seconds if the ssid value of client is greater than -65dB; If the ssid value of client is less than -65dB, switch to 60 seconds period value, and then scan all client every 60 seconds up to 720 seconds. (Section 2) Wu, et al. Expires January 13, 2021 [Page 20] Internet-Draft Adaptive Subscription July 2020 ds:running /ex:example-wifi-mac as:clients/as:client ssid ssid > -65 -65 5 12 ssid < -65 -65 60 12 In another example, the adaptive subscription configuration parameters could also require the server to scan all clients every 5 seconds up to 60 seconds if the difference between maximum value of client ssid and minimum value of client ssid is greater than 0.20dB; If the difference between maximum value of client ssid and minimum value of client ssid is less than 20dB, switch to 60 seconds period value and then scan all client every 60 seconds up to 720 seconds. Wu, et al. Expires January 13, 2021 [Page 21] Internet-Draft Adaptive Subscription July 2020 ds:running /ex:example-wifi-mac as:clients/as:client ssid max(ssid)-min(ssid) >20 20 5 12 max(ssid)-min(ssid) < 20 20 60 12 B.3. "adaptive-update" notification example Upon the server switches to from the update interval 5 seconds to the new update interval 60 seconds, in addition to sending event records to receivers, the "adaptive-update" notification should be generated and sent to the receivers to inform the receivers that the update interval value is switched to the new value. Wu, et al. Expires January 13, 2021 [Page 22] Internet-Draft Adaptive Subscription July 2020 2016-11-21T13:51:00Z 0 60 ds:running /ex:example-wifi-mac Authors' Addresses Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: bill.wu@huawei.com Wei Song Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: songwei80@huawei.com Liang Geng China Mobile 32 Xuanwumen West St, Xicheng District Beijing 10053 Email: gengliang@chinamobile.com Wu, et al. Expires January 13, 2021 [Page 23] Internet-Draft Adaptive Subscription July 2020 Peng Liu China Mobile 32 Xuanwumen West St, Xicheng District Beijing 10053 Email: liupengyjy@chinamobile.com Wu, et al. Expires January 13, 2021 [Page 24]