Time-Variant Routing (tvr) Internet Drafts

      
 TVR (Time-Variant Routing) Use Cases
 
 draft-ietf-tvr-use-cases-09.txt
 Date: 29/02/2024
 Authors: Edward Birrane, Nicolas Kuhn, Yingzhen Qu, Rick Taylor, Li Zhang
 Working Group: Time-Variant Routing (tvr)
 This document introduces use cases where Time-Variant Routing (TVR) computations (i.e. routing computations taking into considerations time-based or scheduled changes to a network) could improve routing protocol convergence and/or network performance.
 TVR (Time-Variant Routing) Requirements
 
 draft-ietf-tvr-requirements-02.txt
 Date: 04/03/2024
 Authors: Daniel King, Luis Contreras, Brian Sipos
 Working Group: Time-Variant Routing (tvr)
 Time-Variant Routing (TVR) refers to the calculation of a path or subpath through a network where the time of message transmission (or receipt) is part of the overall route computation. This means that, all things being equal, a TVR computation might produce different results depending on the time that the computation is performed without other detectable changes to the network topology or other cost functions associated with the route. This document introduces requirements where TVR computations could improve message exchange in a network.
 YANG Data Model for Scheduled Attributes
 
 draft-ietf-tvr-schedule-yang-00.txt
 Date: 16/04/2024
 Authors: Yingzhen Qu, Acee Lindem, Eric Kinzie, Don Fedyk, Marc Blanchet
 Working Group: Time-Variant Routing (tvr)
 The YANG model in this document includes three modules, and can be used to manage network resources and topologies with scheduled attributes, such as predictable link loss and link connectivity as a function of time. The intent is to have this information be utilized by Time-Variant Routing systems.

data-group-menu-data-url="/group/groupmenu.json">

Time-Variant Routing (tvr)

WG Name Time-Variant Routing
Acronym tvr
Area Routing Area (rtg)
State Active
Charter charter-ietf-tvr-01 Approved
Document dependencies
Personnel Chairs Edward J. Birrane, Tony Li
Area Director Gunter Van de Velde
Secretary Adam Wiethuechter
Mailing list Address tvr@ietf.org
To subscribe https://www.ietf.org/mailman/listinfo/tvr
Archive https://mailarchive.ietf.org/arch/browse/tvr/
Chat Room address https://zulip.ietf.org/#narrow/stream/tvr

Charter for Working Group

Existing IETF routing protocols expect to maintain contemporaneous, end-to-end connected paths across a network. Changes to that connectivity, such as the loss of an adjacent peer, need the routing protocols to react to reduce the impact on the network traffic.

However, a growing number of use cases exist where predicted variations (restoration, activation, or loss) to the topology are an expected part of normal network operations. For example, in networks with mobile nodes, such as aerial vehicles and some orbiting spacecraft constellations, links can be lost and re-established, or neighbors may change as a function of their mobility. Similarly, network traffic might be routed based on energy costs or expected user data volumes, which may vary predictably over time in networks prioritizing green computing and energy efficiency. In these cases, the predicted loss and restoration of an adjacency, or formation of an alternate adjacency, should be seen as non-disruptive events. Support for such use cases and expected changes in a routing system is called Time-Variant Routing (TVR).

The Time-Variant Routing Working Group (TVR WG) is chartered to define information and data models that address time-based, scheduled changes to a network. Time-based changes may include changes to links, adjacencies, cost, and - in some cases - traffic volumes. The models are expected to satisfy the non-terrestrial networks' requirements as their main driver. Still, they should be general enough to encompass other types of networks and use cases. They should also be agnostic with respect to other control plane elements.

The WG may also define terminology and concepts where needed, as well as address the impacts of a continually changing topology on the hierarchical structure of the network.

The TVR WG will collaborate with groups working on non-terrestrial networks, including DTN, CCAMP, DETNET, RAW, and DRIP. In addition, the outputs from the WG will be provided to other working groups for consideration, which may use the material to incorporate time-variant attributes and behaviors into individual protocols.

Specifically, the TVR WG will work on these items:

(1) Problem Statement and Use cases

This document (or set of documents) should include a description of the problem statement and related use cases to guide the remaining work. It exists to support the efforts of the Working Group and help newcomers, and it might not be published as an IETF Stream RFC.

(2) Requirements

This document should include definitions, requirements, notes, rationales, and examples.

(3) Information Model

This document (or set of documents) should describe the attributes needed, and the relationship between them, to enable routing and forwarding decisions in the presence of time-variant network parameters.

(4) Data Model

This document (or set of documents) should specify a YANG Data Model (or multiple modules), based on the Information Model, for configuration and monitoring.

(5) Applicability Statement

This document should provide an applicability statement on how the information and data models may be used, along with required ancillary IETF technology, to solve the use cases and requirements.

(6) Implementation and Operational Considerations

This document should provide advice and guidance to implementors and operators.

Milestones

Date Milestone Associated documents
Nov 2024 Implementation and Operational Considerations
Nov 2024 Applicability Statement
Nov 2024 Data Model
Jul 2024 Information Model
Mar 2024 Requirements
Nov 2023 Problem Statement and Use cases