I didn't study the whole report, but I didn't notice any metrics associated with *variance* of latency or bandwidth. It's common for vendors to play games ("Lies, damn lies, and statistics!") to make their metrics look good. A metric of latency that says something like "99% less than N milliseconds" doesn't necessarily translate into an acceptable user performance.

It's also important to look at the specific techniques used for taking measurements. For example, if a measurement is performed every fifteen minutes, extrapolating the metric as representative of all the time between measurements can also lead to a metric judgement which doesn't reflect the reality of what the user actually experiences.

In addition, there's a lot of mechanism between the ISPs' handling of datagrams and the end-user. The users' experience is affected by how all of that mechanism interacts as underlying network behavior changes. When a TCP running in some host decides it needs to retransmit, or an interactive audio/video session discards datagrams because they arrive too late to be useful, the user sees unacceptable performance even though the network operators may think everything is running fine. Measurements from the end-users' perspective might indicate performance is quite different from what measurements at the ISP level suggest.

Gamers are especially sensitive to variance, but it will also apply to interactive uses such as might occur in telemedicine or remote operations. A few years ago I helped a friend do some tests for a gaming situation and we discovered that the average latency was reasonably low, but occasionally, perhaps a few times per hour, latency would increase to 10s of seconds.

In a game, that often means the player loses. In a remote surgery it may mean horrendous outcomes. As more functionality is performed "in the cloud" such situations will become increasingly common.

Jack Haverty

On 2/26/24 12:02, rjmcmahon via Nnagain wrote:

Thanks for sharing this. I'm trying to find out what are the key metrics that will be used for this monitoring. I want to make sure iperf 2 can cover the technical, traffic related ones that make sense to a skilled network operator, including a WiFi BSS manager. I didn't read all 327 pages though, from what I did read, I didn't see anything obvious. I assume these types of KPIs may be in reference docs or something.

Thanks in advance for any help on this.
Bob

And...

Our bufferbloat.net submittal was cited multiple times! Thank you all
for participating in that process!

https://docs.fcc.gov/public/attachments/DOC-400675A1.pdf

It is a long read, and does still start off on the wrong feet (IMHO),
in particular not understanding the difference between idle and
working latency.

It is my hope that by widening awareness of more of the real problems
with latency under load to policymakers and other submitters
downstream from this new FCC document, and more reading what we had to
say, that we will begin to make serious progress towards finally
fixing bufferbloat in the USA.

I do keep hoping that somewhere along the way in the future, the costs
of IPv4 address exhaustion and the IPv6 transition, will also get
raised to the national level. [1]

We are still collecting signatures for what the bufferbloat project
members wrote, and have 1200 bucks in the kitty for further articles
and/or publicity. Thoughts appreciated as to where we can go next with
shifting the national debate about bandwidth in a better direction!
Next up would be trying to get a meeting, and to do an ex-parte
filing, I think, and I wish we could do a live demonstration on
television about it as good as feynman did here:

https://www.youtube.com/watch?v=raMmRKGkGD4

Our original posting is here:
https://docs.google.com/document/d/19ADByjakzQXCj9Re_pUvrb5Qe5OK-QmhlYRLMBY4vH4/edit

Larry's wonderful post is here:
https://circleid.com/posts/20231211-its-the-latency-fcc

[1] How can we get more talking about IPv4 and IPv6, too? Will we have
to wait another year?

https://hackaday.com/2024/02/14/floss-weekly-episode-769-10-more-internet/

--
https://blog.cerowrt.org/post/2024_predictions/
Dave Täht CSO, LibreQos

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