IETF 116 TVR working group meeting


Monday 2023-03-27 06:30 - 08:00 (UTC)

Co-chairs: Tony Li (cTL, TL), Ed Birrane (cEB, EB)
Secretary: Adam Wiethuechter (sAW, AW)

Intro (10 min)

Administrivia: (Chairs, 5 minutes)

Bad joke by cEB to start. (great start, fantastic in fact)

Notewell check. You are being recorded and shall be posted.

Please sign in using Meetecho.

If you want to be in queue, even in room, please join the queue.

Please keep audio and video off unless presenting or asking question.

Please wear a mask if in room unless speaking.

Agenda bash.

Will start with schedule information and why/how use it.

End will be lining up document writing.

Charter and Scoping: (Chairs cTL, 5 minutes)

White on white for slides...what a concept. (another bad joke, 2/2 is
this a trend?)

Ground rules - play nice. Focus on goals



Write a draft! Give presentation! Discuss on list!

cEB: any agenda bash? nope lets move!

Presentations (65 min)

TVR Use Cases Review (Ed Birrane, 5 min)

When did BoF wanted a few use-cases of what trying to accomplish and
their benefits.

Use-cases can be used as rubric for future work.

Case 1: local resource preservation

Case 2: adapting to external conditions

Case 3: mobile devices

Poll: Should these use cases be in a info rfc?

Marc Blanchet (MB): i like use-case info docs if they go clearly into

cEB: fair and noted. still would go through wglc and make sure it work.

Volunteers? multiple authors are good.

The AIXM temporality model and TVR (Emery Annis, 10 min)

On behalf of Brian Sipos.

Background on aero temporality model. existing time variant info model.

Temportality model

AIXM origin

Model structure




Parameter interpolation

Horizontal concept



Jorge Amodio (JA): model free?
EA: published and free to use it
Toerless Ecket (TE): mentioned something as a function rather than
table? worse case example in axim? very interesting for tvr.
EA: is granularity so small that there are 1000s of states over a short
period of time. details would need to be worked out - how to negotiate,
etc. They did not do that they left discret.
TE: following antennas?
cEB: lets move,
Q Misell: does axim a mechanism for confidence of data in model
EA: language and examples in UML for how to convey. It could be added.
shouldnt be part of info model - so users can decide them.

Time Variant Scenarios in the TIDAL network (Li Zhang, 5 min)

Tidel effect of traffic on networks


Example / problems to solve

A Brief History of Contact Graph Routing (Scott Burleigh, 15 min)

No Draft

Deep space

Except of Ulysses pass plan

Mars relay

Contact plans

Contact Graph Routing

Example of CGR

CGR routing table


cEB: can we present such thing at another meeting?
SB: yes!
cEB: thank you for the history. no queue questions.

Forwarding in the Context of TVR (Marc Blanchet, 10 min)



Policies Needed

Drop Policies

Forward Policy


WG adoption and comments

Rick Taylor (RT): if not in scope here can be in dtn. Very relevant in
BP. Open to suggestion from floor if TVR handles this.
cEB: please take to mailing list!
Erik Kline: sceptical useful for IP, will go to list
Ron Velt: forsee support opportunistic routing? lots of work out there
already. PROFIT.
cEB: that is not in scope for TVR. we can take to list.
RV: strange but okay.

A Contact Plan Data Model (Marc Blanchet, 10 min)


Example in JSON


Thanks for early review, WG adoption and comments.

RT: implemented similiar in manet, split metrics away from links
(common). Have dynamic sets of metrics. Some metric may show up so flex
is good. Support adoption, needs work but in good direction.

Using ALTO for Exposing Time-Variant Routing Information (Luis Contreras, 10 min)


Calendared topologies



Wrap-Up (Chairs, 15 min)

Goal behind discussion and presentation; cases and existing work dealing
with schedules

Find commonalities.

Turn into drafts.

Have information use-case document.

Need people to start working on these things.

Go to mailing list, who is interested in what pieces and consolidate
around ideas. Start to collab so there is drafts for next session.

Call for Authors: 5 min

Walk-On Topics: 5 min

Final Comments: 5 min

Open Mic

Dean: info model is somewhat been defined based on Marc document and
other presentations. Lots of options requirements. Well defined for
space; more terrestial use-cases.

cEB: agreed

Stu Card: may have missed; probability!!! predictions and have
uncertaintity. Where is this? We have explicit representation of

cEB: agreed and noted to discuss on list

Lou Berger: dont understand all link attributes for schedule. opaque
attributes. use-case, requirements? We defintely need

cEB: heard and agreed. multiple radios, how to distinguish?

cEB: almost 100 people, clearly something with lots of interest. Active
on mailing list and coordinate on drafts! We will see you all in a
couple months. Understand reqs and info models for time variant

eEB: closes with another terrible joke. it is a trend and as it should