A Common YANG Data Model for Scheduling
draft-ietf-netmod-schedule-yang-02
| Document | Type | Active Internet-Draft (netmod WG) | |
|---|---|---|---|
| Authors | Qiufang Ma , Qin Wu , Mohamed Boucadair , Daniel King | ||
| Last updated | 2024-06-25 | ||
| Replaces | draft-ma-opsawg-schedule-yang | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Yang Validation | 0 errors, 0 warnings | ||
| Reviews |
YANGDOCTORS Early review
by Reshad Rahman
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| Additional resources | Mailing list discussion | ||
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| Document shepherd | (None) | ||
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draft-ietf-netmod-schedule-yang-02
netmod Q. Ma, Ed.
Internet-Draft Q. Wu
Intended status: Standards Track Huawei
Expires: 27 December 2024 M. Boucadair, Ed.
Orange
D. King
Lancaster University
25 June 2024
A Common YANG Data Model for Scheduling
draft-ietf-netmod-schedule-yang-02
Abstract
This document defines a common schedule YANG module which is designed
to be applicable for scheduling purposes such as event, policy,
services, or resources based on date and time. For the sake of
better modularity, the module includes basic, intermediate, and
advanced versions of recurrence related groupings.
Discussion Venues
This note is to be removed before publishing as an RFC.
Discussion of this document takes place on the Operations and
Management Area Working Group Working Group mailing list
(opsawg@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/browse/opsawg/.
Source for this draft and an issue tracker can be found at
https://github.com/boucadair/policy-based-network-acl.
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."
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This Internet-Draft will expire on 27 December 2024.
Copyright Notice
Copyright (c) 2024 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
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Editorial Note (To be removed by RFC Editor) . . . . . . 3
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 4
3. Module Overview . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Features . . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. Types and Identities . . . . . . . . . . . . . . . . . . 5
3.3. Groupings . . . . . . . . . . . . . . . . . . . . . . . . 5
3.3.1. The "generic-schedule-params" Grouping . . . . . . . 6
3.3.2. The "period-of-time" Grouping . . . . . . . . . . . . 8
3.3.3. The "recurrence" Grouping . . . . . . . . . . . . . . 9
3.3.4. The "recurrence-utc" Grouping . . . . . . . . . . . . 11
3.3.5. The "recurrence-with-time-zone" Grouping . . . . . . 12
3.3.6. The "recurrence-utc-with-date-times" Grouping . . . . 14
3.3.7. The "recurrence-time-zone-with-date-times"
Grouping . . . . . . . . . . . . . . . . . . . . . . 15
3.3.8. The "icalendar-recurrence" Grouping . . . . . . . . . 17
3.3.9. The "schedule-status" and "schedule-status-with-name"
Groupings . . . . . . . . . . . . . . . . . . . . . . 19
3.4. Features Use and Augmentations . . . . . . . . . . . . . 21
4. Some Usage Restrictions . . . . . . . . . . . . . . . . . . . 22
5. Relationship to the DISMAN-SCHEDULE-MIB . . . . . . . . . . . 22
6. The "ietf-schedule" YANG Module . . . . . . . . . . . . . . . 23
7. Security Considerations . . . . . . . . . . . . . . . . . . . 41
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 41
8.1. The "IETF XML" Registry . . . . . . . . . . . . . . . . . 41
8.2. The "YANG Module Names" Registry . . . . . . . . . . . . 41
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 42
9.1. Normative References . . . . . . . . . . . . . . . . . . 42
9.2. Informative References . . . . . . . . . . . . . . . . . 43
Appendix A. Examples of Format Representation . . . . . . . . . 45
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A.1. The "generic-schedule-params" Grouping . . . . . . . . . 45
A.2. The "period-of-time" Grouping . . . . . . . . . . . . . . 45
A.3. The "recurrence" Grouping . . . . . . . . . . . . . . . . 46
A.4. The "recurrence-utc" Grouping . . . . . . . . . . . . . . 46
A.5. The "recurrence-with-time-zone" Grouping . . . . . . . . 47
A.6. The "recurrence-utc-with-date-times" Grouping . . . . . . 47
A.7. The "recurrence-time-zone-with-date-times" Grouping . . . 48
A.8. The "icalendar-recurrence" Grouping . . . . . . . . . . . 49
A.9. The "schedule-status" Grouping . . . . . . . . . . . . . 50
Appendix B. Examples of Using/Extending the "ietf-schedule"
Module . . . . . . . . . . . . . . . . . . . . . . . . . 50
B.1. Example: Schedule Tasks to Execute Based on a Recurrence
Rule . . . . . . . . . . . . . . . . . . . . . . . . . . 50
B.2. Example: Schedule Network Properties to Change Based on
Date and Time . . . . . . . . . . . . . . . . . . . . . . 53
Appendix C. Examples of Using "ietf-schedule" Module for Scheduled
Use of Resources Framework . . . . . . . . . . . . . . . 56
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 57
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 58
1. Introduction
This document defines a common schedule YANG module ("ietf-schedule")
that can be used in several scheduling contexts, e.g., (but not
limited to) [I-D.ietf-opsawg-ucl-acl],
[I-D.contreras-opsawg-scheduling-oam-tests], and
[I-D.ietf-tvr-schedule-yang]. The module includes a set of reusable
groupings which are designed to be applicable for scheduling purposes
such as event, policy, services or resources based on date and time.
This document does not make any assumption about the nature of
actions that are triggered by the schedules.
Section 5 discusses relationship with the managed objects defined in
[RFC3231].
Appendix A describes a set of examples to illustrate the use of the
common schedule groupings (Section 3.3). And Appendix B provides
sample modules to exemplify how future modules can use the
extensibility provisions in "ietf-schedule" (Section 6). Also,
Appendix C provides an example of using "ietf-schedule" module for
scheduled use of resources framework (e.g., [RFC8413]).
1.1. Editorial Note (To be removed by RFC Editor)
Note to the RFC Editor: This section is to be removed prior to
publication.
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This document contains placeholder values that need to be replaced
with finalized values at the time of publication. This note
summarizes all of the substitutions that are needed. No other RFC
Editor instructions are specified elsewhere in this document.
Please apply the following replacements:
* XXXX --> the assigned RFC number for this draft
* 2024-04-16 --> the actual date of the publication of this document
2. Conventions and Definitions
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 meanings of the symbols in tree diagrams are defined in
[RFC8340].
This document uses the YANG terminology defined in Section 3 of
[RFC7950].
The document makes use of the following terms:
icalendar: Refers to Internet Calendaring per [RFC5545].
System: Refers to an entity that host a schedule that is managed
using the YANG module defined in this document.
3. Module Overview
3.1. Features
The "ietf-schedule" data model defines the recurrence related
groupings using a modular approach. Basic, intermediate, and
advanced representation of recurrence groupings are defined, with
each reusing the previous one and adding more parameters. To allow
for different options, two features are defined in the data model:
* "basic-recurrence-supported"
* "icalendar-recurrence-supported"
Refer to Section 3.4 for the use of these features.
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3.2. Types and Identities
The "ietf-schedule" module (Section 6) defines the following
identities:
* "frequency-type": Characterizes the repeating interval rule of a
schedule (per second, per minute, etc.).
* "schedule-type": Indicates the type of a schedule. The following
types are defined so far:
- one-shot: The schedule will trigger an action without the
duration/end time being specified and then the schedule will
disable itself (Section 3.3 of [RFC3231]).
- period: The schedule is a period-based schedule consisting
either a start and end or a start and positive duration of
time.
- recurrence: This type is used for a recurrence-based schedule
* "schedule-state": Indicates the status of a schedule (enabled,
disabled, finished, etc.).
* "discard-action": Specifies the action to perform when a schedule
is discarded (e.g., generate a warning or an error message).
3.3. Groupings
The "ietf-schedule" module (Section 6) defines the following
groupings:
* "generic-schedule-params" (Section 3.3.1)
* "period-of-time" (Section 3.3.2)
* "recurrence" (Section 3.3.3)
* "recurrence-utc" (Section 3.3.4)
* "recurrence-with-time-zone" (Section 3.3.5)
* "recurrence-utc-with-date-times" (Section 3.3.6)
* "recurrence-time-zone-with-date-times" (Section 3.3.7)
* "icalendar-recurrence" (Section 3.3.8)
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* "schedule-status" and "schedule-status-with-name" (Section 3.3.9)
Figure 1 provides an overview of the tree structure of the "ietf-
schedule" module in terms of its groupings.
module: ietf-schedule
grouping generic-schedule-params:
...
grouping period-of-time:
...
grouping recurrence:
...
grouping recurrence-utc:
...
grouping recurrence-with-time-zone:
...
grouping recurrence-utc-with-date-times:
...
grouping recurrence-time-zone-with-date-times:
...
grouping icalendar-recurrence:
...
grouping schedule-status:
...
grouping schedule-status-with-name:
...
Figure 1: Overall Schedule Tree Structure
Each of these groupings is presented in the following subsections.
Examples are provided in Appendix A.
3.3.1. The "generic-schedule-params" Grouping
A system accepts and handles the schedule requests, which may help
further automate the scheduling process of events, policy, services,
or resources based on date and time. The "generic-schedule-params"
grouping (Figure 2) specifies a set of configuration parameters that
are used by a system for validating requested schedules.
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module: ietf-schedule
grouping generic-schedule-params:
+-- description? string
+-- time-zone-identifier? sys:timezone-name
+-- validity? yang:date-and-time
+-- max-allowed-start? yang:date-and-time
+-- min-allowed-start? yang:date-and-time
+-- max-allowed-end? yang:date-and-time
+-- discard-action? identityref
grouping period-of-time:
...
grouping recurrence:
...
grouping recurrence-utc:
...
grouping recurrence-with-time-zone:
...
grouping recurrence-utc-with-date-times:
...
grouping recurrence-time-zone-with-date-times:
...
grouping icalendar-recurrence:
...
grouping schedule-status:
...
grouping schedule-status-with-name:
...
Figure 2: Generic Schedule Configuration Tree Structure
The "description" includes a description of the schedule. No
constraint is imposed on the structure nor the use of this parameter.
The "time-zone-identifier" parameter, if provided, specifies the time
zone reference of the date and time values with local time format.
The "validity" parameter specifies the date and time after which a
schedule will be considered as invalid. It determines the latest
time that a schedule can be executed by a system and takes precedence
over similar attributes that are provided at the schedule instance
itself.
The "max/min-allowed-start" parameters specify the maximum/minimum
scheduled start date and time, a requested schedule will be rejected
if the first occurrence of the schedule is later/earlier than the
configured values.
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The "max-allowed-end" parameter specifies the maximum allowed end
time of the last occurrence. A requested schedule will be rejected
if the end time of last occurrence is later than the configured "max-
allowed-end" value.
The "discard-action" parameter specifies the action if a requested
schedule is considered inactive or out-of-date.
These parameters apply to all schedules on a system and are meant to
provide guards against stale configuration, too short schedule
requests that would prevent validation by admins of some critical
systems, etc.
3.3.2. The "period-of-time" Grouping
The "period-of-time" grouping (Figure 3) represents a time period
using either a start ("period-start") and end date and time ("period-
end"), or a start ("period-start") and a positive time duration
("duration"). For the first format, the start of the period MUST be
before the end of the period.
The "period-description" includes a description of the period. No
constraint is imposed on the structure nor the use of this parameter.
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module: ietf-schedule
grouping generic-schedule-params:
...
grouping period-of-time:
+-- period-description? string
+-- period-start yang:date-and-time
+-- time-zone-identifier? sys:timezone-name
+-- (period-type)?
+--:(explicit)
| +-- period-end? yang:date-and-time
+--:(duration)
+-- duration? duration
grouping recurrence:
...
grouping recurrence-utc:
...
grouping recurrence-with-time-zone:
...
grouping recurrence-utc-with-date-times:
...
grouping recurrence-time-zone-with-date-times:
...
grouping icalendar-recurrence:
...
grouping schedule-status:
...
grouping schedule-status-with-name:
...
Figure 3: Period of Time Grouping Tree Structure
3.3.3. The "recurrence" Grouping
The "recurrence" grouping (Figure 4) specifies a simple recurrence
rule.
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module: ietf-schedule
grouping generic-schedule-params:
...
grouping period-of-time:
...
grouping recurrence:
+-- recurrence-description? string
+-- frequency identityref
+-- interval? uint32
grouping recurrence-utc:
...
grouping recurrence-with-time-zone:
...
grouping recurrence-utc-with-date-times:
...
grouping recurrence-time-zone-with-date-times:
...
grouping icalendar-recurrence:
...
grouping schedule-status:
...
grouping schedule-status-with-name:
...
Figure 4: recurrence Grouping Tree Structure
The frequency ("frequency") which is mandatory, identifies the type
of recurrence rule. For example, a "daily" frequency value specifies
repeating events based on an interval of a day or more.
Consistent with Section 3.3.10 of [RFC5545], the interval
("interval") represents at which intervals the recurrence rule
repeats. For example, within a daily recurrence rule, an interval
value of "8" means every eight days. The default value is "1",
meaning every second for a secondly recurrence rule, every minute for
a minutely rule, every hour for an hourly rule, every day for a daily
rule, and so on. Note that per Section 4.13 of
[I-D.ietf-netmod-rfc8407bis], no "default" substatement is used here
because there are cases (e.g., profiling) where the use of the
default is problematic.
The "recurrence-description" includes a description of the period.
No constraint is imposed on the structure nor the use of this
parameter.
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3.3.4. The "recurrence-utc" Grouping
The "recurrence-utc" grouping (Figure 5) uses the "recurrence"
grouping and specifies a simple recurrence rule in UTC format.
module: ietf-schedule
grouping generic-schedule-params:
...
grouping period-of-time:
...
grouping recurrence:
...
grouping recurrence-utc:
+-- recurrence-first
| +-- utc-start-time? yang:date-and-time
| +-- duration? uint32
+-- (recurrence-bound)?
| +--:(until)
| | +-- utc-until? yang:date-and-time
| +--:(count)
| +-- count? uint32
+-- recurrence-description? string
+-- frequency identityref
+-- interval? uint32
grouping recurrence-with-time-zone:
...
grouping recurrence-utc-with-date-times:
...
grouping recurrence-time-zone-with-date-times:
...
grouping icalendar-recurrence:
...
grouping schedule-status:
...
grouping schedule-status-with-name:
...
Figure 5: recurrence-utc Grouping Tree Structure
The "utc-start-time" indicates the start time in UTC format.
The "duration" parameter specifies, in units of seconds, the time
period of the first occurrence. Unless specified otherwise, the
"duration" also applies to subsequent recurrence instances.
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Note that the "interval" and "duration" cover two distinct properties
of a schedule event. The interval specifies when a schedule will
occur, combined with the frequency parameter; while the duration
indicates how long an occurence will last.
The repetition can be scoped by a specified end time or by a count of
occurrences, indicated by the "recurrence-bound" choice. The "utc-
start-time" value always counts as the first occurrence.
The "recurrence-utc" grouping is designed to be reused in scheduling
contexts where machine readability is more desirable.
3.3.5. The "recurrence-with-time-zone" Grouping
The "recurrence-with-time-zone" grouping (Figure 6) uses the
"recurrence" grouping and specifies a simple recurrence rule with a
time zone.
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module: ietf-schedule
grouping generic-schedule-params:
...
grouping period-of-time:
...
grouping recurrence:
...
grouping recurrence-utc:
...
grouping recurrence-with-time-zone:
+-- recurrence-first
| +-- date-time-start? yang:date-and-time
| +-- duration? duration
| +-- time-zone-identifier? sys:timezone-name
+-- (recurrence-bound)?
| +--:(until)
| | +-- until? yang:date-and-time
| +--:(count)
| +-- count? uint32
+-- recurrence-description? string
+-- frequency identityref
+-- interval? uint32
grouping recurrence-utc-with-date-times:
...
grouping recurrence-time-zone-with-date-times:
...
grouping icalendar-recurrence:
...
grouping schedule-status:
...
grouping schedule-status-with-name:
...
Figure 6: recurrence-with-time-zone Grouping Tree Structure
The "recurrence-first" container includes "date-time-start" and
"duration" parameters to specify the start time and period of the
first occurrence. Unless specified otherwise, the "duration" also
applies to subsequent recurrence instances. It also includes a
"time-zone-identifier" parameter which MUST be specified if the date
and time value is neither reported in the format of UTC nor time zone
offset to UTC.
The repetition can be scoped by a specified end time or by a count of
occurrences, indicated by the "recurrence-bound" choice. The "date-
time-start" value always counts as the first occurrence.
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Unlike the definition of "recurrence-utc" grouping (Section 3.3.4),
"recurrence-with-time-zone" is intended to promote human readability
over machine readability.
3.3.6. The "recurrence-utc-with-date-times" Grouping
The "recurrence-utc-with-date-times" grouping (Figure 7) uses the
"recurrence-utc" grouping (Section 3.3.4) and adds a "period-
timeticks" list to define an aggregate set of repeating occurrences.
module: ietf-schedule
grouping generic-schedule-params:
...
grouping period-of-time:
...
grouping recurrence:
...
grouping recurrence-utc:
...
grouping recurrence-with-time-zone:
...
grouping recurrence-utc-with-date-times:
+-- recurrence-first
| +-- utc-start-time? yang:date-and-time
| +-- duration? uint32
+-- (recurrence-bound)?
| +--:(until)
| | +-- utc-until? yang:date-and-time
| +--:(count)
| +-- count? uint32
+-- recurrence-description? string
+-- frequency identityref
+-- interval? uint32
+-- period-timeticks* [period-start]
+-- period-start yang:timeticks
+-- period-end? yang:timeticks
grouping recurrence-time-zone-with-date-times:
...
grouping icalendar-recurrence:
...
grouping schedule-status:
...
grouping schedule-status-with-name:
...
Figure 7: recurrence-utc-with-date-times Grouping Tree Structure
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The recurrence instances are specified by the union of occurrences
defined by both the recurrence rule and "period-timeticks" list.
Duplicate instances are ignored. The value of the "period-start"
instance must not exceed the value indicated by the value of
"frequency" instance, e.g., the timeticks value must not exceed 100
in a secondly recurrence rule, and it must not exceed 6000 in a
minutely recurrence rule, and so on.
3.3.7. The "recurrence-time-zone-with-date-times" Grouping
The "recurrence-time-zone-with-date-times" grouping (Figure 8) uses
the "recurrence-with-time-zone" grouping (Section 3.3.5) and adds a
"period" list to define an aggregate set of repeating occurrences.
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module: ietf-schedule
grouping generic-schedule-params:
...
grouping period-of-time:
...
grouping recurrence:
...
grouping recurrence-utc:
...
grouping recurrence-with-time-zone:
...
grouping recurrence-utc-with-date-times:
...
grouping recurrence-time-zone-with-date-times:
+-- recurrence-first
| +-- date-time-start? yang:date-and-time
| +-- duration? duration
| +-- time-zone-identifier? sys:timezone-name
+-- (recurrence-bound)?
| +--:(until)
| | +-- until? yang:date-and-time
| +--:(count)
| +-- count? uint32
+-- recurrence-description? string
+-- frequency identityref
+-- interval? uint32
+-- period* [period-start]
+-- period-description? string
+-- period-start yang:date-and-time
+-- time-zone-identifier? sys:timezone-name
+-- (period-type)?
+--:(explicit)
| +-- period-end? yang:date-and-time
+--:(duration)
+-- duration? duration
grouping icalendar-recurrence:
...
grouping schedule-status:
...
grouping schedule-status-with-name:
...
Figure 8: recurrence-time-zone-with-date-times Grouping Tree
Structure
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The recurrence instances are specified by the union of occurrences
defined by both the recurrence rule and "period" list. Duplicate
instances are ignored.
3.3.8. The "icalendar-recurrence" Grouping
The "icalendar-recurrence" grouping (Figure 9) uses the "recurrence-
time-zone-with-date-times" grouping (Section 3.3.7) and define more
data nodes to enrich the definition of recurrence. The structure of
the "icalendar-recurrence" grouping refers to the definition of
recurrence component defined in Sections 3.3.10 and 3.8.5 of
[RFC5545].
module: ietf-schedule
grouping generic-schedule-params:
...
grouping period-of-time:
...
grouping recurrence:
...
grouping recurrence-utc:
...
grouping recurrence-with-time-zone:
...
grouping recurrence-utc-with-date-times:
...
grouping recurrence-time-zone-with-date-times:
...
grouping icalendar-recurrence:
+-- recurrence-first
| +-- date-time-start? yang:date-and-time
| +-- duration? duration
| +-- time-zone-identifier? sys:timezone-name
+-- (recurrence-bound)?
| +--:(until)
| | +-- until? yang:date-and-time
| +--:(count)
| +-- count? uint32
+-- recurrence-description? string
+-- frequency identityref
+-- interval? uint32
+-- period* [period-start]
| +-- period-description? string
| +-- period-start yang:date-and-time
| +-- time-zone-identifier? sys:timezone-name
| +-- (period-type)?
| +--:(explicit)
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| | +-- period-end? yang:date-and-time
| +--:(duration)
| +-- duration? duration
+-- bysecond* uint32
+-- byminute* uint32
+-- byhour* uint32
+-- byday* [weekday]
| +-- direction* int32
| +-- weekday schedule:weekday
+-- bymonthday* int32
+-- byyearday* int32
+-- byyearweek* int32
+-- byyearmonth* uint32
+-- bysetpos* int32
+-- workweek-start? schedule:weekday
+-- exception-dates* yang:date-and-time
grouping schedule-status:
...
grouping schedule-status-with-name:
...
Figure 9: icalendar-recurrence Grouping Tree Structure
An array of the "bysecond" (or "byminute", "byhour") specifies a list
of seconds within a minute (or minutes within an hour, hours of the
day). For example, within a "minutely" recurrence rule, the values
of "byminute" node "10" and "20" means the occurrences generates at
the 10th and 20th minute within an hour, reducing the number of
recurrence instances from all minutes.
The parameter "byday" specifies a list of days of the week, with an
optional direction which indicates the nth occurrence of a specific
day within the "monthly" or "yearly" frequency. For example, within
a "monthly" rule, the "weekday" with a value of "monday" and the
"direction" with a value of "-1" represents the last Monday of the
month.
An array of the "bymonthday" (or byyearday", "byyearweek", or
"byyearmonth") specifies a list of days of the month (or days of the
year, weeks of the year, or months of the year). For example, within
a "yearly" recurrence rule, the values of "byyearmonth" instance "1"
and "2" means the occurrences generates in January and February,
increasing the "yearly" recurrence from every year to every January
and February of the year.
The "bysetpos" conveys a list of values that corresponds to the nth
occurrence within the set of recurrence instances to be specified.
For example, in a "monthly" recurrence rule, the "byday" data node
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specifies every Monday of the week, the "bysetpos" with value of "-1"
represents the last Monday of the month. Not setting the "bysetpos"
data node represents every Monday of the month.
The "workweek-start" data node specifies the day on which the week
starts. This is significant when a "weekly" recurrence rule has an
interval greater than 1, and a "byday" data node is specified. This
is also significant when in a "yearly" rule and a "byyearweek" is
specified. The default value is "monday".
The "exception-dates" data node specifies a list of exceptions for
recurrence. The final recurrence set is generated by gathering all
of the date and time values generated by any of the specified
recurrence rule and date-times, and then excluding any start date and
time values specified by "exception-dates" parameter.
3.3.9. The "schedule-status" and "schedule-status-with-name" Groupings
The "schedule-status" and "schedule-status-with-name" groupings
(Figure 10) define common parameters for scheduling management/status
exposure. The "schedule-status-with-name" grouping has the same
structure as "schedule-status" but with an additional parameter to
identify a schedule "schedule-id". Both structures are defined in
the module to allow for better modularity and flexibility.
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module: ietf-schedule
grouping generic-schedule-params:
...
grouping period-of-time:
...
grouping recurrence:
...
grouping recurrence-utc:
...
grouping recurrence-with-time-zone:
...
grouping recurrence-utc-with-date-times:
...
grouping recurrence-time-zone-with-date-times:
...
grouping icalendar-recurrence:
...
grouping schedule-status:
+-- state? identityref
+-- version? uint16
+-- schedule-type? identityref
+--ro local-time? yang:date-and-time
+--ro last-update? yang:date-and-time
+--ro counter? yang:counter32
+--ro last-occurrence? yang:date-and-time
+--ro upcoming-occurrence? yang:date-and-time
+--ro last-failed-occurrence? yang:date-and-time
+--ro failure-counter? yang:counter32
grouping schedule-status-with-name:
+-- schedule-id? string
+-- state? identityref
+-- version? uint16
+-- schedule-type? identityref
+--ro local-time? yang:date-and-time
+--ro last-update? yang:date-and-time
+--ro counter? yang:counter32
+--ro last-occurrence? yang:date-and-time
+--ro upcoming-occurrence? yang:date-and-time
+--ro last-failed-occurrence? yang:date-and-time
+--ro failure-counter? yang:counter32
Figure 10: Schedule Status with and without Name Groupings Tree
Structure
The "schedule-id" parameter is useful to uniquely identify a schedule
in a network device or controller if multiple scheduling contexts
exists.
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The "state" parameter is defined to configure/expose the scheduling
state, depending on the use of the grouping. The "identityref" type
is used for this parameter to allow extensibility in future modules.
For example, a "conflict" state is valid in scheduling contexts where
multiple systems struggle for the scheduling of the same property.
The conflict may be induced by, e.g., multiple entities managing the
schedules for the same target component.
The "version" parameter is used to track the current schedule version
information. The version can be bumped by the entity who create the
schedule. The "last-update" parameter identifies when the schedule
was last modified. In some contexts, this parameter can be used to
track the configuration of a given schedule. In such cases, the
"version" may not be used.
The "schedule-type" parameter identifies the type of the current
schedule. The "counter", "last-occurrence", and "upcoming-
occurrence" data nodes are only avaliable when the "schedule-type" is
"recurrence".
"local-time" reports the actual local time as seen by the entity that
host a schedule. This paramter can be used by a controller to infer
the offset to UTC.
"last-failed-occurrence" and "failure-counter" report the last
failure that occured and the count of failures for this schedule.
The current groupings capture common parameters that are applicable
to typical scheduling contexts known so far. Future modules can
define other useful parameters as needed. For example, in a
scheduling context with multiple system sources to feed the
schedules, the "source" and "precedence" parameters may be needed to
reflect how schedules from different sources should be prioritised.
3.4. Features Use and Augmentations
Appendix B.1 provides an example about how the features defined in
Section 3.1 can be used. Implementations may support a basic
recurrence rule or an advanced one as needed, by declaring different
features. Whether only one or both features are supported is
implementation specific and depend on specific scheduling context.
The common schedule groupings (Section 3.3) can also be augmented to
support specific needs. As an example, Appendix B.2 demonstrates how
additional parameters can be added to comply with specifc schedule
needs.
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4. Some Usage Restrictions
There are some restrictions that need to be followed when using
groupings defined in the "ietf-schedule" YANG module (Section 3.3):
* The instant in time represented by "period-start" MUST be before
the "period-end" for "period-of-time" grouping (Section 3.3.2).
* The combination of the day, month, and year represented for date
and time values MUST be valid. See Section 5.7 of [RFC3339] for
the maxinum day number based on the month and year.
* The second MUST have the value "60" at the end of months in which
a leap second occurs for date and time values.
* Schedules received with a starting time in the past with respect
to current time SHOULD be ignored.
5. Relationship to the DISMAN-SCHEDULE-MIB
[RFC3231] specifies a Management Information Base (MIB) used to
schedule management operations periodically or at specified dates and
times.
Despite no data nodes are defined in this document, Table 1 lists how
main objects in the DISMAN-SCHEDULE-MIB can be mapped to YANG
parameters.
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+==================+========================+
| MIB Object | YANG |
+==================+========================+
| schedLocalTime | local-time |
+------------------+------------------------+
| schedType | schedule-type |
+------------------+------------------------+
| schedName | schedule-id |
+------------------+------------------------+
| schedOwner | Not Supported |
+------------------+------------------------+
| schedDescr | description |
+------------------+------------------------+
| schedInterval | interval |
+------------------+------------------------+
| schedWeekDay | weekday |
+------------------+------------------------+
| schedMonth | byyearmonth |
+------------------+------------------------+
| schedDay | bymonthday |
+------------------+------------------------+
| schedHour | byhour |
+------------------+------------------------+
| schedMinute | byminute |
+------------------+------------------------+
| schedContextName | Not Supported |
+------------------+------------------------+
| schedAdminStatus | state |
+------------------+------------------------+
| schedOperStatus | state |
+------------------+------------------------+
| schedFailures | failure-counter |
+------------------+------------------------+
| schedLastFailure | Not Supported |
+------------------+------------------------+
| schedLastFailed | last-failed-occurrence |
+------------------+------------------------+
| schedStorageType | Not Supported |
+------------------+------------------------+
| schedValue | Not Supported |
+------------------+------------------------+
Table 1: YANG/MIB Mapping
6. The "ietf-schedule" YANG Module
This module imports types defined in [RFC6991] and [RFC7317].
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<CODE BEGINS> file "ietf-schedule@2024-04-16.yang"
module ietf-schedule {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-schedule";
prefix schedule;
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-system {
prefix sys;
reference
"RFC 7317: A YANG Data Model for System Management";
}
organization
"IETF NETMOD Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
Editor: Qiufang Ma
<mailto:maqiufang1@huawei.com
Author: Qin Wu
<mailto:bill.wu@huawei.com>
Editor: Mohamed Boucadair
<mailto:mohamed.boucadair@orange.com>
Author: Daniel King
<mailto:d.king@lancaster.ac.uk>";
description
"This YANG module defines a set of common types and groupings
which are applicable for scheduling purposes such as events,
policy, services, or resources based on date and time.
Copyright (c) 2024 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 Revised
BSD License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
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(https://www.rfc-editor.org/info/rfcXXXX); see the RFC
itself for full legal notices.
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 (RFC 2119) (RFC 8174) when, and only when,
they appear in all capitals, as shown here.";
revision 2024-04-16 {
description
"Initial revision.";
reference
"RFC XXXX: A Common YANG Data Model for Scheduling";
}
feature basic-recurrence-supported {
description
"Indicates that the server supports configuring a basic
scheduled recurrence.";
}
feature icalendar-recurrence-supported {
description
"Indicates that the server supports configuring a comprehensive
scheduled icalendar recurrence";
reference
"RFC 5545: Internet Calendaring and Scheduling Core Object
Specification (iCalendar),
Sections 3.3.10 and 3.8.5";
}
typedef weekday {
type enumeration {
enum sunday {
value 0;
description
"Sunday of the week.";
}
enum monday {
value 1;
description
"Monday of the week.";
}
enum tuesday {
value 2;
description
"Tuesday of the week.";
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}
enum wednesday {
value 3;
description
"Wednesday of the week.";
}
enum thursday {
value 4;
description
"Thursday of the week.";
}
enum friday {
value 5;
description
"Friday of the week.";
}
enum saturday {
value 6;
description
"Saturday of the week.";
}
}
description
"Seven days of the week.";
}
typedef duration {
type string {
pattern '((\+)?|\-)P((([0-9]+)D)?(T(0[0-9]|1[0-9]|2[0-3])'
+ ':[0-5][0-9]:[0-5][0-9]))|P([0-9]+)W';
}
description
"Duration of the time. The format can represent nominal
durations (weeks designated by 'W' and days designated by 'D')
and accurate durations (hours:minutes:seconds follows the
designator 'T').
Note that this value type doesn't support the 'Y' and 'M'
designators to specify durations in terms of years and months.
Negative durations are typically used to schedule an alarm to
trigger before an associated time.";
reference
"RFC 5545: Internet Calendaring and Scheduling Core Object
Specification (iCalendar), Sections 3.3.6 and
3.8.6.3";
}
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identity frequency-type {
description
"Base identity for frequency type.";
}
identity secondly {
base frequency-type;
description
"Indicates a repeating rule based on an interval of
a second or more.";
}
identity minutely {
base frequency-type;
description
"Indicates a repeating rule based on an interval of
a minute or more.";
}
identity hourly {
base frequency-type;
description
"Indicates a repeating rule based on an interval of
an hour or more.";
}
identity daily {
base frequency-type;
description
"Indicates a repeating rule based on an interval of
a day or more.";
}
identity weekly {
base frequency-type;
description
"Indicates a repeating rule based on an interval of
a week or more.";
}
identity monthly {
base frequency-type;
description
"Indicates a repeating rule based on an interval of
a month or more.";
}
identity yearly {
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base frequency-type;
description
"Indicates a repeating rule based on an interval of
a year or more.";
}
identity schedule-type {
description
"Base identity for schedule type.";
}
identity one-shot {
base schedule-type;
description
"Indicates a one-shot schedule. That is a schedule that
will trigger an action without the duration/end time being
specified and then the schedule will disable itself.";
}
identity period {
base schedule-type;
description
"Indicates a period-based schedule consisting either a
start and end or a start and positive duration of time.";
}
identity recurrence {
base schedule-type;
description
"Indicates a recurrence-based schedule.";
}
identity schedule-state {
description
"Base identity for schedule state.";
}
identity enabled {
base schedule-state;
description
"Indicates a recurrence with an enabled state.";
}
identity finished {
base schedule-state;
description
"Indicates a recurrence with a finished state.
The finished state indicates that the schedule has ended.";
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}
identity disabled {
base schedule-state;
description
"Indicates a recurrence with a disabled state.";
}
identity out-of-date {
base schedule-state;
description
"Indicates a recurrence with an out-of-date state.";
}
identity discard-action {
description
"Indicates that a schedule will be discarded.";
}
identity warning {
base discard-action;
description
"Indicates that a warning message is generated
when a schedule is discarded.";
}
identity error {
base discard-action;
description
"Indicates that an error message is generated
when a schedule is discarded.";
}
identity silently-discard {
base discard-action;
description
"Indicates that an invalid schedule is silently
discarded.";
}
grouping generic-schedule-params {
description
"Includes a set of generic parameters that are followed by
the entity that supports schedules.
Such parameters are used as guards to prevent, e.g., stale
configuration.";
leaf description {
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type string;
description
"Provides a description of the schedule.";
}
leaf time-zone-identifier {
type sys:timezone-name;
description
"Indicates the identifier for the time zone.";
}
leaf validity {
type yang:date-and-time;
description
"Specifies the date and time after which a schedule will
be considered as invalid. This parameter takes precedence
over similar attributes that are provided at the schedule
instance itself.";
}
leaf max-allowed-start {
type yang:date-and-time;
description
"Specifies the maximum scheduled start date and time.
A requested schedule whose first instance occurs after
this value cannot be accepted by the entity. Specifically,
a requested schedule will be rejected if the first
occurrence of that schedule exceeds 'max-allowed-start'.";
}
leaf min-allowed-start {
type yang:date-and-time;
description
"Specifies the minimum scheduled start date and time.
A requested schedule whose first instance occurs before
this value cannot be accepted by the entity. Specifically,
a requested schedule will be rejected if the first
occurrence of that schedule is scheduled before
'min-allowed-start'.";
}
leaf max-allowed-end {
type yang:date-and-time;
description
"A requested schedule will be rejected if the end time of
the last occurrence exceeds 'max-allowed-end'.";
}
leaf discard-action {
type identityref {
base discard-action;
}
description
"Specifies the behavior when a schedule is discarded when
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enforcing the guards in this grouping or it is received
out-of-date.";
}
}
grouping period-of-time {
description
"This grouping is defined for period of time property.";
reference
"RFC 5545: Internet Calendaring and Scheduling Core Object
Specification (iCalendar), Section 3.3.9";
leaf period-description {
type string;
description
"Provides a description of the period.";
}
leaf period-start {
type yang:date-and-time;
mandatory true;
description
"Period start time.";
}
leaf time-zone-identifier {
type sys:timezone-name;
description
"Indicates the identifier for the time zone in a time zone
database. This parameter MUST be specified if 'period-start'
value is neither reported in the format of UTC nor time zone
offset to UTC.";
}
choice period-type {
description
"Indicates the type of the time period. Two types are
supported.";
case explicit {
description
"A period of time is identified by its start and its end.
'period-start' indicates the period start.";
leaf period-end {
type yang:date-and-time;
description
"Period end time. The start MUST be before the end. If a
local time without time zone offset to UTC time is
specified, it MUST use the same time zone reference as
'period-start' parameter. If 'period-start' also uses a
local time without time zone offset to UTC, it MUST use
the time zone as specified by the
'time-zone-identifier' parameter.";
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}
}
case duration {
description
"A period of time is defined by a start and a positive
duration of time.";
leaf duration {
type duration {
pattern 'P((([0-9]+)D)?(T(0[0-9]|1[0-9]|2[0-3])'
+ ':[0-5][0-9]:[0-5][0-9]))|P([0-9]+)W';
}
description
"A positive duration of the time. This value is
equivalent to the format of duration type except that
the value cannot be negative.";
}
}
}
}
grouping recurrence {
description
"A simple definition of recurrence.";
leaf recurrence-description {
type string;
description
"Provides a description of the recurrence.";
}
leaf frequency {
type identityref {
base frequency-type;
}
mandatory true;
description
"Specifies the frequency type of the recurrence rule.";
}
leaf interval {
type uint32;
description
"A positive integer representing at which intervals the
recurrence rule repeats. For example, within a 'daily'
recurrence rule, a value of '8' means every eight days.
The default value is '1', means every second for a
'secondly' recurrence rule, every minute for a 'minutely'
rule, and so on.";
}
}
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grouping recurrence-utc {
description
"A simple definition of recurrence with time specified in
UTC. This grouping is intended to be machine-friendly.";
container recurrence-first {
description
"Specifies the first instance of the recurrence.";
leaf utc-start-time {
type yang:date-and-time;
description
"Defines the instant date and time of the first instance
in the recurrence set. A UTC format MUST be used.";
}
leaf duration {
type uint32;
units "seconds";
description
"When specified, it indicates how long the first occurrence
last. Unless specified otherwise, it also applies to all
the other instances in the recurrence set.";
}
}
choice recurrence-bound {
description
"Modes to bound the recurrence rule. If no choice is
indicated, the recurrence rule is considered to repeat
forever.";
case until {
description
"This case defines a way that bounds the recurrence
rule in an inclusive manner.";
leaf utc-until {
type yang:date-and-time;
description
"This parameter specifies a date and time value to
inclusively bound the recurrence in UTC format. If
the value specified by this parameter is synchronized
with the specified recurrence, it becomes the last
instance of the recurrence.";
}
}
case count {
description
"This case defines the number of occurrences at which
to range-bound the recurrence.";
leaf count {
type uint32;
description
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"The positive number of occurrences at which to
range-bound the recurrence.";
}
}
}
uses recurrence;
}
grouping recurrence-with-time-zone {
description
"A simple definition of recurrence to specify the time
with a local time and time zone identifier. This grouping
is intended to be human-friendly.";
container recurrence-first {
description
"Specifies the first instance of the recurrence.";
leaf date-time-start {
type yang:date-and-time;
description
"Defines the instant date and time of the first instance
in the recurrence set.";
}
leaf duration {
type duration;
description
"When specified, it indicates how long the first
occurrence last. Unless specified otherwise, it also
applies to all the other instances in the recurrence
set.";
}
leaf time-zone-identifier {
type sys:timezone-name;
description
"Indicates the identifier for the time zone in a time
zone database. This parameter MUST be specified if
'date-time-start' or 'until' value is neither
reported in the format of UTC nor time zone offset to
UTC.";
}
}
choice recurrence-bound {
description
"Modes to bound the recurrence rule. If no choice is
indicated, the recurrence rule is considered to repeat
forever.";
case until {
description
"The end of the recurrence is indicated by a specific
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date-and-time value.";
leaf until {
type yang:date-and-time;
description
"Specifies a date and time value to bound the
recurrence. If the value specified by this parameter
is synchronized with the specified recurrence, it
becomes the last instance of the recurrence.";
}
}
case count {
description
"The end of the recurrence is indicated by the number
of occurrences.";
leaf count {
type uint32;
description
"The positive number of occurrences at which to
range-bound the recurrence.";
}
}
}
uses recurrence;
}
grouping recurrence-utc-with-date-times {
description
"This grouping defines an aggregate set of repeating
occurrences with UTC time format. The recurrence instances
are specified by the occurrences defined by both the
recurrence rule and 'period-timeticks' list. Duplicate
instances are ignored.";
uses recurrence-utc;
list period-timeticks {
key "period-start";
description
"A list of periods with timeticks formats.";
leaf period-start {
type yang:timeticks;
must
"(not(derived-from(../../frequency,"
+"'schedule:secondly')) or (current() < 100)) and "
+"(not(derived-from(../../frequency,"
+"'schedule:minutely')) or (current() < 6000)) and "
+"(not(derived-from(../../frequency,'schedule:hourly'))"
+" or (current() < 360000)) and "
+"(not(derived-from(../../frequency,'schedule:daily'))"
+" or (current() < 8640000)) and "
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+"(not(derived-from(../../frequency,'schedule:weekly'))"
+" or (current() < 60480000)) and "
+"(not(derived-from(../../frequency,"
+"'schedule:monthly')) or (current() < 267840000)) and "
+"(not(derived-from(../../frequency,'schedule:yearly'))"
+" or (current() < 3162240000))" {
error-message
"The period-start must not exceed the frequency
interval.";
}
description
"Start time of the schedule within one recurrence.";
}
leaf period-end {
type yang:timeticks;
description
"End time of the schedule within one recurrence.";
}
}
}
grouping recurrence-time-zone-with-date-times {
description
"This grouping defines an aggregate set of repeating
occurrences with local time format and time zone specified.
The recurrence instances are specified by the occurrences
defined by both the recurrence rule and 'period' list.
Duplicate instances are ignored.";
uses recurrence-with-time-zone;
list period {
key "period-start";
description
"A list of periods with date-and-time formats.";
uses period-of-time;
}
}
grouping icalendar-recurrence {
description
"This grouping specifies properties of a recurrence rule.";
reference
"RFC 5545: Internet Calendaring and Scheduling Core Object
Specification (iCalendar), Section 3.8.5";
uses recurrence-time-zone-with-date-times;
leaf-list bysecond {
type uint32 {
range "0..60";
}
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description
"Specifies a list of seconds within a minute.";
}
leaf-list byminute {
type uint32 {
range "0..59";
}
description
"Specifies a list of minutes within an hour.";
}
leaf-list byhour {
type uint32 {
range "0..23";
}
description
"Specifies a list of hours of the day.";
}
list byday {
key "weekday";
description
"Specifies a list of days of the week.";
leaf-list direction {
when "derived-from(../../frequency, 'schedule:monthly') or "
+ "(derived-from(../../frequency, 'schedule:yearly') "
+ " and not(../../byyearweek))";
type int32 {
range "-53..-1|1..53";
}
description
"When specified, it indicates the nth occurrence of a
specific day within the monthly or yearly recurrence
rule. For example, within a monthly rule, +1 monday
represents the first monday within the month, whereas
-1 monday represents the last monday of the month.";
}
leaf weekday {
type schedule:weekday;
description
"Corresponds to seven days of the week.";
}
}
leaf-list bymonthday {
type int32 {
range "-31..-1|1..31";
}
description
"Specifies a list of days of the month.";
}
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leaf-list byyearday {
type int32 {
range "-366..-1|1..366";
}
description
"Specifies a list of days of the year.";
}
leaf-list byyearweek {
when "derived-from(../frequency, 'schedule:yearly')";
type int32 {
range "-53..-1|1..53";
}
description
"Specifies a list of weeks of the year.";
}
leaf-list byyearmonth {
type uint32 {
range "1..12";
}
description
"Specifies a list of months of the year.";
}
leaf-list bysetpos {
type int32 {
range "-366..-1|1..366";
}
description
"Specifies a list of values that corresponds to the nth
occurrence within the set of recurrence instances
specified by the rule. It must only be used in conjunction
with another by the rule part.";
}
leaf workweek-start {
type schedule:weekday;
description
"Specifies the day on which the workweek starts. The
default value is 'monday'.";
}
leaf-list exception-dates {
type yang:date-and-time;
description
"Defines a list of exceptions for recurrence.";
}
}
grouping schedule-status {
description
"This grouping defines common properties of scheduling
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status.";
leaf state {
type identityref {
base schedule-state;
}
description
"Indicates the current state of the schedule.";
}
leaf version {
type uint16;
description
"Indicates the version number of the schedule.";
}
leaf schedule-type {
type identityref {
base schedule-type;
}
description
"Indicates the schedule type.";
}
leaf local-time {
type yang:date-and-time;
config false;
description
"Reports the local time as used by the entity that
hosts the schedule.";
}
leaf last-update {
type yang:date-and-time;
config false;
description
"Reports the timestamp that the schedule is last updated.";
}
leaf counter {
when "derived-from-or-self(../schedule-type, "
+ "'schedule:recurrence')";
type yang:counter32;
config false;
description
"The counter of occurrences since the schedule was enabled.
The count wraps around when it reaches the maximum value.";
}
leaf last-occurrence {
when "derived-from-or-self(../schedule-type, "
+ "'schedule:recurrence')";
type yang:date-and-time;
config false;
description
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"Indicates the timestamp of last occurrence.";
}
leaf upcoming-occurrence {
when "derived-from-or-self(../schedule-type, "
+ "'schedule:recurrence')"
+ "and derived-from-or-self(../state, 'schedule:enabled')";
type yang:date-and-time;
config false;
description
"Indicates the timestamp of next occurrence.";
}
leaf last-failed-occurrence {
when "derived-from-or-self(../schedule-type, "
+ "'schedule:recurrence')";
type yang:date-and-time;
config false;
description
"Indicates the timestamp of last failed action triggered by
the schedule.";
}
leaf failure-counter {
when "derived-from-or-self(../schedule-type, "
+ "'schedule:recurrence')";
type yang:counter32;
config false;
description
"Counts the number of failures while invoking the scheduled
action.";
}
}
grouping schedule-status-with-name {
description
"This grouping defines common properties of scheduling
status.";
leaf schedule-id {
type string;
description
"The schedule identifier that uniquely identifies a
schedule within a device, controller, network, etc.
The unicity scope depends on the implementation.";
}
uses schedule-status;
}
}
<CODE ENDS>
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7. Security Considerations
This section uses the template described in Section 3.7 of
[I-D.ietf-netmod-rfc8407bis].
The "ietf-schedule" YANG module specified in this document defines
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 Network 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.
The "ietf-schedule" module defines a set of types and groupings.
These nodes are intended to be reused by other YANG modules. The
module by itself does not expose any data nodes that are writable,
data nodes that contain read-only state, or RPCs. As such, there are
no additional security issues related to the "ietf- schedule" module
that need to be considered.
Care must be taken when defining recurrences occurring very often and
frequent that can be an additional source of attacks by keeping the
system permanently busy with the management of scheduling.
8. IANA Considerations
8.1. The "IETF XML" Registry
This document registers the following URI in the "IETF XML Registry"
[RFC3688].
URI: urn:ietf:params:xml:ns:yang:ietf-schedule
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
8.2. The "YANG Module Names" Registry
This document registers the following YANG module in the "YANG Module
Names" registry [RFC6020].
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name: ietf-schedule
namespace: urn:ietf:params:xml:ns:yang:ietf-schedule
prefix: schedule
maintained by IANA? N
reference: RFC XXXX
9. References
9.1. 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,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC3231] Levi, D. and J. Schoenwaelder, "Definitions of Managed
Objects for Scheduling Management Operations", RFC 3231,
DOI 10.17487/RFC3231, January 2002,
<https://www.rfc-editor.org/rfc/rfc3231>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/rfc/rfc3688>.
[RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and
Scheduling Core Object Specification (iCalendar)",
RFC 5545, DOI 10.17487/RFC5545, September 2009,
<https://www.rfc-editor.org/rfc/rfc5545>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/rfc/rfc6020>.
[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/rfc/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/rfc/rfc6242>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/rfc/rfc6991>.
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[RFC7317] Bierman, A. and M. Bjorklund, "A YANG Data Model for
System Management", RFC 7317, DOI 10.17487/RFC7317, August
2014, <https://www.rfc-editor.org/rfc/rfc7317>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/rfc/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/rfc/rfc8040>.
[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/rfc/rfc8174>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/rfc/rfc8341>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/rfc/rfc8446>.
9.2. Informative References
[I-D.contreras-opsawg-scheduling-oam-tests]
Contreras, L. M. and V. Lopez, "A YANG Data Model for
Network Diagnosis by scheduling sequences of OAM tests",
Work in Progress, Internet-Draft, draft-contreras-opsawg-
scheduling-oam-tests-01, 10 July 2023,
<https://datatracker.ietf.org/doc/html/draft-contreras-
opsawg-scheduling-oam-tests-01>.
[I-D.ietf-netmod-eca-policy]
Wu, Q., Bryskin, I., Birkholz, H., Liu, X., and B. Claise,
"A YANG Data model for ECA Policy Management", Work in
Progress, Internet-Draft, draft-ietf-netmod-eca-policy-01,
19 February 2021, <https://datatracker.ietf.org/doc/html/
draft-ietf-netmod-eca-policy-01>.
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[I-D.ietf-netmod-rfc8407bis]
Bierman, A., Boucadair, M., and Q. Wu, "Guidelines for
Authors and Reviewers of Documents Containing YANG Data
Models", Work in Progress, Internet-Draft, draft-ietf-
netmod-rfc8407bis-12, 21 June 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netmod-
rfc8407bis-12>.
[I-D.ietf-opsawg-ucl-acl]
Ma, Q., Wu, Q., Boucadair, M., and D. King, "A YANG Data
Model and RADIUS Extension for Policy-based Network Access
Control", Work in Progress, Internet-Draft, draft-ietf-
opsawg-ucl-acl-04, 6 June 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-opsawg-
ucl-acl-04>.
[I-D.ietf-tvr-schedule-yang]
Qu, Y., Lindem, A., Kinzie, E., Fedyk, D., and M.
Blanchet, "YANG Data Model for Scheduled Attributes", Work
in Progress, Internet-Draft, draft-ietf-tvr-schedule-yang-
00, 16 April 2024, <https://datatracker.ietf.org/doc/html/
draft-ietf-tvr-schedule-yang-00>.
[I-D.ietf-tvr-use-cases]
Birrane, E. J., Kuhn, N., Qu, Y., Taylor, R., and L.
Zhang, "TVR (Time-Variant Routing) Use Cases", Work in
Progress, Internet-Draft, draft-ietf-tvr-use-cases-09, 29
February 2024, <https://datatracker.ietf.org/doc/html/
draft-ietf-tvr-use-cases-09>.
[I-D.liu-netmod-yang-schedule]
Liu, X., Bryskin, I., Beeram, V. P., Saad, T., Shah, H.
C., and O. G. de Dios, "A YANG Data Model for
Configuration Scheduling", Work in Progress, Internet-
Draft, draft-liu-netmod-yang-schedule-05, 1 March 2018,
<https://datatracker.ietf.org/doc/html/draft-liu-netmod-
yang-schedule-05>.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet:
Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
<https://www.rfc-editor.org/rfc/rfc3339>.
[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG",
RFC 7951, DOI 10.17487/RFC7951, August 2016,
<https://www.rfc-editor.org/rfc/rfc7951>.
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[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/rfc/rfc8340>.
[RFC8413] Zhuang, Y., Wu, Q., Chen, H., and A. Farrel, "Framework
for Scheduled Use of Resources", RFC 8413,
DOI 10.17487/RFC8413, July 2018,
<https://www.rfc-editor.org/rfc/rfc8413>.
Appendix A. Examples of Format Representation
This section provides some examples to illustrate the use of the
period and recurrence formats defined in Section 6. Note that a
"grouping" does not define any data nodes in the schema tree; the
examples illustrated are thus for the ease of understanding. Only
the message body is provided with JSON used for encoding per the
guidance in [RFC7951].
A.1. The "generic-schedule-params" Grouping
Figure 11 indicates the example of a requested schedule that needs to
start no earlier than 08:00 AM, January 1, 2025 and end no later than
8:00 PM, January 31, 2025 (Beijing time). Schedule requests that
fail to meet the requirements are ignored by the system.
{
"time-zone-identifier": "China/Beijing",
"min-allowed-start": "2025-01-01T08:00:00",
"max-allowed-end": "2025-01-31T20:00:00",
"discard-action": "ietf-schedule:silently-discard"
}
Figure 11: Generic Parameters for Schedule Validation
A.2. The "period-of-time" Grouping
Figure 12 shows an example of a period that starts at 08:00:00 UTC,
on January 1, 2025 and ends at 18:00:00 UTC on December 31, 2027.
{
"period-start": "2025-01-01T08:00:00Z",
"period-end": "2027-12-31T18:00:00Z"
}
Figure 12: Simple Start/End Schedule
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An example of a period that starts at 08:00:00 UTC, on January 1,
2025 and lasts 15 days and 5 hours and 20 minutes is encoded as shown
in Figure 13.
{
"period-start": "2025-01-01T08:00:00Z",
"duration": "P15DT05:20:00"
}
Figure 13: Simple Schedule with Duration
An example of a period that starts at 2:00 A.M. in Los Angeles on
November 19, 2025 and lasts 20 weeks is depicted in Figure 14.
{
"period-start": "2025-11-19T02:00:00",
"time-zone-identifier": "America/Los_Angeles",
"duration": "P20W"
}
Figure 14: Simple Schedule with Time Zone Indication
A.3. The "recurrence" Grouping
Figure 17 indicates a recurrence of every 2 days which starts
immediately and repeat forever:
{
"recurrence-description": "forever recurrence rule",
"frequency": "ietf-schedule:daily",
"interval": 2,
}
Figure 15: Simple Schedule with Recurrence
A.4. The "recurrence-utc" Grouping
Figure 16 indicates a recurrence from 8:00 AM to 9:00 AM every day,
from December 1 to December 31, 2025 in UTC:
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{
"recurrence-first": {
"utc-start-time": "2025-12-01T08:00:00Z",
"duration": 3600;
},
"frequency": "ietf-schedule:daily",
"interval": 1,
"utc-until": "2025-12-31T23:59:59Z"
}
Figure 16: Simple Schedule with Recurrence in UTC
A.5. The "recurrence-with-time-zone" Grouping
Figure 17 indicates a recurrence of every 2 hours for 10 occurrences,
lasting 10 minutes, and starting at 3 p.m. on December 1, 2025 in New
York:
{
"recurrence-first": {
"date-time-start": "2025-12-01T15:00:00",
"duration": "PT00:10:00",
"time-zone-identifier": "America/New_York"
},
"frequency": "ietf-schedule:hourly",
"interval": 2,
"count": 10
}
Figure 17: Simple Schedule with Recurrence with Time Zone Indication
A.6. The "recurrence-utc-with-date-times" Grouping
Figure 18 indicates a recurrence that occurs every two days starting
at 9:00 AM and 3:00 PM for a duration of 30 minutes and 40 minutes
respectively, from 2025-06-01 to 2025-06-30 in UTC:
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{
"recurrence-first": {
"utc-start-time": "2025-06-01T09:00:00Z",
},
"frequency": "ietf-schedule:daily",
"interval": 2,
"utc-until": "2025-06-30T23:59:59Z",
"period-timeticks": [
{
"period-start": "3240000",
"period-end": "3420000"
},
{
"period-start": "5400000",
"period-end": "5640000"
}
]
}
Figure 18: Example of Recurrence With Date Times
A.7. The "recurrence-time-zone-with-date-times" Grouping
Figure 19 indicates a recurrence that occurs every 30 minutes and
last for 15 minutes from 9:00 AM to 5:00 PM, and extra two
occurrences at 6:00 PM and 6:30 PM with each lasting for 20 minutes
on 2025-12-01 (New York):
{
"recurrence-first": {
"date-time-start": "2025-12-01T09:00:00",
"duration": "PT00:15:00",
"time-zone-identifier": "America/New_York"
},
"frequency": "ietf-schedule:minutely",
"interval": 30,
"until": "2025-12-01T17:00:00Z",
"period": [
{
"period-start": "2025-12-01T18:00:00",
"duration": "PT00:20:00"
},
{
"period-start": "2025-12-01T18:30:00",
"duration": "PT00:20:00"
}
]
}
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Figure 19: Example of Advanced Recurrence Schedule
A.8. The "icalendar-recurrence" Grouping
Figure 20 indicates 10 occurrences that occur at 8:00 AM (EST), every
last Saturday of the month starting in January 2024:
{
"recurrence-first": {
"date-time-start": "2024-01-27T08:00:00",
"time-zone-identifier": "America/New_York"
},
"frequency": "ietf-schedule:monthly",
"count": 10,
"byday": [
{
"direction": [-1],
"weekday": "saturday"
}
]
}
Figure 20: Simple iCalendar Recurrence
Figure 21 is an example of a recurrence that occurs on the last
workday of the month until December 25, 2025, from January 1, 2025:
{
"recurrence-first": {
"date-time-start": "2025-01-01"
},
"frequency": "ietf-schedule:monthly",
"until": "2025-12-25",
"byday": [
{ "weekday": "monday"},
{ "weekday": "tuesday"},
{ "weekday": "wednesday"},
{ "weekday": "thursday"},
{ "weekday": "friday"}
],
"bysetpos": [-1]
}
Figure 21: Example of Advanced iCalendar Recurrence
Figure 22 indicates a recurrence that occurs every 20 minutes from
9:00 AM to 4:40 PM (UTC), with the occurrence starting at 10:20 AM
being excluded on 2025-12-01:
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{
"recurrence-first": {
"date-time-start": "2025-12-01T09:00:00Z"
},
"until": "2025-12-01T16:40:00Z",
"frequency": "ietf-schedule:minutely",
"byminute": [0, 20, 40],
"byhour": [9, 10, 11, 12, 13, 14, 15, 16],
"exception-dates": ["2025-12-01T10:20:00Z"]
}
Figure 22: Example of Advanced iCalendar Recurrence with Exceptions
A.9. The "schedule-status" Grouping
Figure 23 indicates the scheduled recurrence status of Figure 22 at
the time of 12:15 PM, 2025-12-01 (UTC):
{
"state": "ietf-schedule:enabled",
"version": 1,
"schedule-type": "ietf-schedule:recurrence",
"counter": 9,
"last-occurrence": ["2025-12-01T12:00:00Z"],
"upcoming-occurrence": ["2025-12-01T12:20:00Z"]
}
Figure 23: Example of a Schedule Status
At the time of 12:15 PM, 2025-12-01 (UTC), the recurring event
occurred at (note that occurrence at 10:20 AM is excluded): 9:00,
9:20, 9:40, 10:00, 10:40, 11:00, 11:20, 11:40, 12:00. The last
occurrence was at 12:00, the upcoming one is at 12:20.
Appendix B. Examples of Using/Extending the "ietf-schedule" Module
This non-normative section shows two examples for how the "ietf-
schedule" module can be used or extended for scheduled events or
attributes based on date and time.
B.1. Example: Schedule Tasks to Execute Based on a Recurrence Rule
Scheduled tasks can be used to execute specific actions based on
certain recurrence rules (e.g., every Friday at 8:00 AM). The
following example module which "uses" the "icalendar-recurrence"
grouping from "ietf-schedule" module shows how a scheduled task could
be defined with different features used for options.
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module example-scheduled-backup {
yang-version 1.1;
namespace "http://example.com/example-scheduled-backup";
prefix "ex-scback";
import ietf-inet-types {
prefix "inet";
}
import ietf-schedule {
prefix "schedule";
}
organization
"Example, Inc.";
contact
"Support at example.com";
description
"Example of a module defining an scheduled based backup
operation.";
revision "2023-01-19" {
description
"Initial Version.";
reference
"RFC XXXX: A YANG Data Model for Scheduling.";
}
container scheduled-backup-tasks {
description
"A container for backing up all current running configuration
on the device.";
list tasks {
key "task-id";
description
"The list of backing up tasks on this device.";
leaf task-id {
type string;
description
"The task identifier that uniquely identifies a scheduled
backup task.";
}
choice local-or-remote {
description
"Specifies whether the configuration to be backed up is
local or remote.";
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case local {
description
"Configuration parameters for backing up of local
devices.";
leaf local {
type empty;
description
"The parameter specifies the configuration to be
backed up is on the local device.";
}
}
case remote {
description
"Configuration parameters for backing up of remote
devices.";
leaf remote {
type inet:domain-name;
description
"The parameter specifies the remote device domain
name.";
}
}
}
container basic-recurrence-schedules {
if-feature schedule:basic-recurrence-supported;
description
"Basic recurrence schedule specification, only applies when
schedule:basic-recurrence-supported feaure is supported.";
leaf schedule-id {
type string;
description
"The schedule identifier for this recurrence rule.";
}
uses schedule:recurrence;
}
container icalendar-recurrence-schedules {
if-feature schedule:icalendar-recurrence-supported;
description
"Basic recurrence schedule specification, only applies when
schedule:icalendar-recurrence-supported feaure is
supported.";
leaf schedule-id {
type string;
description
"The schedule identifier for this recurrence rule.";
}
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uses schedule:icalendar-recurrence;
}
}
list schedule-set {
key "schedule-id";
description
"The list of schedule status for the backup tasks.";
uses schedule:schedule-status;
}
}
}
B.2. Example: Schedule Network Properties to Change Based on Date and
Time
Network properties may change over a specific period of time or based
on a recurrence rule, e.g., [I-D.ietf-tvr-use-cases]. The following
example module which augments the "recurrence-utc-with-date-times"
grouping from "ietf-schedule" module shows how a scheduled based
attribute could be defined.
module example-scheduled-link-bandwidth {
yang-version 1.1;
namespace "http://example.com/example-scheduled-link-bandwidth";
prefix "ex-scattr";
import ietf-network {
prefix "nw";
reference
"RFC 8345: A YANG Data Model for Network Topologies";
}
import ietf-schedule {
prefix "schedule";
reference
"RFC XXXX: A YANG Data Model for Scheduling";
}
organization
"Example, Inc.";
contact
"Support at example.com";
description
"Example of a module defining a scheduled link bandwidth.";
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revision "2023-01-19" {
description
"Initial Version.";
reference
"RFC XXXX: A YANG Data Model for Scheduling.";
}
grouping link-bandwidth-grouping {
description
"Grouping of the link bandwidth definition.";
leaf scheduled-bandwidth {
type uint64;
units "Kbps";
description
"Bandwidth values, expressed in kilobits per second.";
}
}
container link-attributes {
description
"Definition of link attributes.";
list link {
key "source-node destination-node";
description
"Definition of link attributes.";
leaf source-node {
type nw:node-id;
description
"Indicates the source node identifier.";
}
leaf destination-node {
type nw:node-id;
description
"Indicates the source node identifier.";
}
leaf default-bandwidth {
type uint64;
units "Kbps";
description
"Default bandwidth values when unspecified.";
}
choice time-variant-type {
description
"Controls the schedule type.";
case period {
uses schedule:period-of-time;
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}
case recurrence {
uses schedule:recurrence-utc-with-date-times {
augment "period-timeticks" {
description
"Specifies the attributes inside each
period-timeticks entry.";
uses link-bandwidth-grouping;
}
}
}
}
}
}
}
Figure 24 shows a configuration example of a link's bandwidth that is
scheduled between 2025-12-01 0:00 UTC to the end of 2025-12-31 with a
daily schedule. In each day, the bandwidth value is scheduled to be
500 Kbps between 1:00 AM to 6:00 AM and 800 Kbps between 10:00 PM to
11:00 PM. The bandwidth value that's not covered by the period above
is 1000 Kbps by default.
<?xml version="1.0" encoding="utf-8"?>
<link-attributes
xmlns="http://example.com/example-scheduled-link-bandwidth"
xmlns:schedule="urn:ietf:params:xml:ns:yang:ietf-schedule">
<link>
<source-node>ne1</source-node>
<destination-node>ne2</destination-node>
<default-bandwidth>1000</default-bandwidth>
<recurrence-first>
<utc-start-time>2025-12-01T01:00:00Z</utc-start-time>
</recurrence-first>
<frequency>schedule:daily</frequency>
<utc-until>2025-12-31T23:59:59Z</utc-until>
<period-timeticks>
<period-start>360000</period-start>
<period-end>2160000</period-end>
<scheduled-bandwidth>500</scheduled-bandwidth>
</period-timeticks>
<period-timeticks>
<period-start>7920000</period-start>
<period-end>8280000</period-end>
<scheduled-bandwidth>800</scheduled-bandwidth>
</period-timeticks>
</link>
</link-attributes>
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Figure 24: Example of Scheduled Link's Bandwidth
Appendix C. Examples of Using "ietf-schedule" Module for Scheduled Use
of Resources Framework
This section exemplifies how the architecture for supporting
scheduled reservation of Traffic Engineering (TE) resources in
[RFC8413] might leverage the "period-of-time" grouping defined in the
"ietf-schedule" module to implement scheduled use of resources.
The following example module shows how a scheduled link capacity
reservation could be defined.
module example-sch-capacity-res {
yang-version 1.1;
namespace "http://example.com/example-sch-capacity-res";
prefix "ex-schecaparev";
import ietf-network-topology {
prefix "nt";
}
import ietf-schedule {
prefix "schedule";
}
container link-capability-reservations {
list scheduled-link-capacity {
key "schedule-id";
leaf schedule-id {
type string;
}
leaf link-id {
type nt:link-id;
}
leaf reserved-capability {
type uint64;
units "Mbps";
}
uses schedule:period-of-time;
}
}
}
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Section 4 of [RFC8413] defines the reference architecture for
scheduled use of resources, the service requester sends a request to
a Path Computation Element (PCE) and includes the parameters of the
Label Switched Path (LSP) that the requester wishes to supply, the
configuration example to provide the scheduled resource is shown in
Figure 25.
<?xml version="1.0" encoding="utf-8"?>
<link-capability-reservations
xmlns="http://example.com/example-sch-capacity-res"
xmlns:schedule="urn:ietf:params:xml:ns:yang:ietf-schedule">
<scheduled-link-capacity>
<schedule-id>1</schedule-id>
<link-id>1-2-1</link-id>
<reserved-capability>500</reserved-capability>
<period-start>2025-03-10T08:00:00Z</period-start>
<period-end>2025-03-10T09:00:00Z</period-end>
</scheduled-link-capacity>
<scheduled-link-capacity>
<schedule-id>2</schedule-id>
<link-id>2-1-1</link-id>
<reserved-capability>400</reserved-capability>
<period-start>2025-04-01T00:00:00Z</period-start>
<duration>PT09:00:00</duration>
</scheduled-link-capacity>
<scheduled-link-capacity>
<schedule-id>3</schedule-id>
<link-id>2-1-1</link-id>
<reserved-capability>500</reserved-capability>
<period-start>2025-04-01T09:00:00Z</period-start>
<period-end>2025-04-01T23:59:59Z</period-end>
</scheduled-link-capacity>
</link-capability-reservations>
Figure 25: Example of Scheduled Link's Bandwidth Reservation
Acknowledgments
This work is derived from the [I-D.ietf-opsawg-ucl-acl]. There is a
desire from the OPSAWG to see this model be separately defined for
wide use in scheduling context.
Thanks to Adrian Farrel, Wei Pan, Tianran Zhou, Joe Clarke, and Dhruv
Dhody for their valuable comments and inputs to this work.
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Many thanks to the authors of [I-D.ietf-tvr-schedule-yang],
[I-D.contreras-opsawg-scheduling-oam-tests], and
[I-D.ietf-netmod-eca-policy] for the constructive discussion during
IETF#118.
Other related efforts were explored in the past, e.g.,
[I-D.liu-netmod-yang-schedule].
Authors' Addresses
Qiufang Ma (editor)
Huawei
101 Software Avenue, Yuhua District
Jiangsu
210012
China
Email: maqiufang1@huawei.com
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Jiangsu
210012
China
Email: bill.wu@huawei.com
Mohamed Boucadair (editor)
Orange
35000 Rennes
France
Email: mohamed.boucadair@orange.com
Daniel King
Lancaster University
United Kingdom
Email: d.king@lancaster.ac.uk
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