IRTF Open Meeting

Thursday, 27 July 2023, at 13:00-15:00 Pacific Time
Room: Continental 6

Chair: Colin Perkins
Minutes: Colin Perkins
Recording: YouTube

Introduction and Status Update

Speaker: Colin Perkins, IRTF Chair

Slides

Model-Based Insights on the Performance, Fairness, and Stability of BBR

Speaker: Simon Scherrer

Paper
Slides

Discussion:

• Colin Perkins thanked the speaker for a great talk and noted that it's
  really nice that this both confirms prior experimental results and made
  new predications that were demonstrated in practice.

• Cedric Westphal asked how the comparison of RED vs drop tail queuing was
  modelled

• Simon Scherrer showed the calculations and noted that the equations that
  model the queuing behaviour can distinguish drop tail and RED

• Cedric asked if the comparison with other TCP variants uses updated
  models for TCP Cubic and Reno too?

• Simon replied that they use the existing models for TCP Cubic and Reno
  to ensure a fair comparison with prior work.

• David Morley asked if the model can you capture application limited
  behaviour?

• Simon replied that this is not yet included in the model, but they can
  see how to incorporate it in a future extension of their work.

• Dave Plonka asked about the scalability of the model. The talk showed
  experiments with three flows; does it scale to many more flows?

• Simon replied that simulating one flow is not that expensive; the cost
  mostly comes from simulating large topologies.

• Dave followed-up to ask if the model was scaled-up, would it be trusted
  to be accurate or would additional experimental evaluation be needed to
  confirm?

• Simon replied that they have reasonable confidence that it will scale
  and remain accurate.

• Colin Perkins asked if the model includes start-up dynamics.

• Simon replied that it does not, but that it would be possible to develop
  a new fluid model for the start-up phase and switch over

• Colin asked if the model can readily be extended to model BBRv3, as
  presented in the CCWG meeting earlier in the week.

• Simon said that he believed the model can be extended to model the new
  additions in BBRv3.

SCALE: Automatically Finding RFC Compliance Bugs in DNS Nameservers

Speaker: Siva Kakarla

Paper

Siva Kakarla's presentation was postponed due to illness and will take
place during the IRTF Open Meeting at IETF 118.