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Time Variant Routing

Document Type Approved BOF request
Title Time Variant Routing
Last updated 2022-09-29
State Approved
Editor Rick Taylor
Responsible leadership Alvaro Retana
Additional resources Mailing List
Send notices to (None)

Name: Time Variant Routing (TVR)


Existing 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, are considered to be
exceptional circumstances that must be corrected prior to the resumption
of data transmission. Corrections may include attempting to re-establish
lost adjacencies and recalculating or rediscovering a functional topology.

However, there are a growing number of use-cases where changes
to the routing topology are an expected part of network operations. In these
cases the pre-planned loss and restoration of an adjacency, or formation of
an alternate adjacency, should be seen as a non-disruptive event.

The expected loss (and planned resumption) of links can occur for a
variety of reasons. In networks with mobile nodes, such as unmanned
aerial vehicles and some orbiting spacecraft constellations, links are
lost and re-established as a function of the mobility of the platforms.
In networks without reliable access to power, such as networks
harvesting energy from wind and solar, link activity might be restricted
to certain times of day. Similarly in networks prioritizing green
computing and energy efficiency over data rate, network traffic might be
planned around energy costs or expected user data volumes.

The Time Variant Routing Working Group (TVR-WG) will be chartered to
develop a common set of definitions, attributes, behaviors, and
algorithms necessary to evaluate routing and forwarding decisions in the
presence of planned loss and resumption of network connectivity.

The outputs of the TVR-WG will be reviewed by, and provided to, other
Routing Area Working Groups so that time-variant attributes and
behaviors can be appropriately incorporated into individual routing
protocols by the relevant Working Groups.

Required Details:

  • Status: WG Forming
  • Responsible AD: Alvaro Retana (
  • BoF Proponents: Rick Taylor (, Ed Birrane (
  • BoF Chairs: TBD
  • Number of people expected to attend: 50
  • Length of Session: 90 minutes
  • Conflicts: Routing, DTN
  • Chair Conflicts: TBD
  • Technology Overlap: dtn, manet
  • Key Participant Conflict: Rick Taylor, Ed Birrane, Alvaro Retana, Erik Kline

Information for IAB/IESG



  • Administrivia / Chairs / 5 minutes

  • Problem Statement and Use Cases / TBD / 40 minutes
    -- Problem Statement Description / TBD / 10 minutes
    -- Orbiting Spacecraft Use Case / TBD / 10 minutes
    -- Power-related Use Case / TBD / 10 minutes
    -- TBD Use Case (?) / TBD / 10 minutes

  • Open Mic/Discussion / All / 15 minutes

  • Charter Discussion / Chairs / 15 minutes

  • Conclusions and Next Steps / Chairs and AD / 15 minutes

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