Higher than expected density of upload speeds around 0 Mbps

[Justus Fries]

Hello everyone,

some recent papers used the M-Lab data for their analysis [1,2].

Both of these papers show the upload speed test data (fig. 6 for [1] and fig. 9(b) for [2]) and if you look closely, there is a higher (than I would expect) number of upload tests very close to 0 Mbps across geographies.

Has anyone looked into a reason for this before or has an intuition on what is going on with those tests?

Best regards

Justus Fries

[1] Udit Paul, Jiamo Liu, Mengyang Gu, Arpit Gupta, and Elizabeth Belding. 2022. The importance of contextualization of crowdsourced active speed test measurements. In Proceedings of the 22nd ACM Internet Measurement Conference (IMC '22). Association for Computing Machinery, New York, NY, USA, 274–289. https://doi.org/10.1145/3517745.3561441
[2] Nitinder Mohan, Andrew E. Ferguson, Hendrik Cech, Rohan Bose, Prakita Rayyan Renatin, Mahesh K. Marina, and Jörg Ott. 2024. A Multifaceted Look at Starlink Performance. In Proceedings of the ACM on Web Conference 2024 (WWW '24). Association for Computing Machinery, New York, NY, USA, 2723–2734. https://doi.org/10.1145/3589334.3645328

[Matt Mathis]

How slow?  One of my long standing questions has been what are the slowest speeds that NDT can reliably measure?  I recall seeing a relatively sharp mode at 128 kb/s (one of the standard DSL speeds),  I didn't see much data below that, and in particular I didn't see modes at either 56kb/s or 9.6kb/s the old standard dial up speeds.  It is plausible that such things are totally gone, but it is also plausible that the clients fail at these speeds, for example if the smallest message takes more wire time than the test completion watchdog timer.   These details are not totally uniform across all implementations, so it is possible that different clients have different minimum reliable measurement rates.

BTW the most likely outcome would be an aborted test, with no data in BQ (and not zero or other random small value).

Thanks,

--MM--
Evil is defined by mortals who think they know "The Truth" and use force to apply it to others. 
-------------------------------------------

Matt Mathis  (Email is best)

Home & mobile: 412-654-7529 please leave a message if you must call.

--
You received this message because you are subscribed to the Google Groups "discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email to discuss+u...@measurementlab.net.
To view this discussion on the web visit https://groups.google.com/a/measurementlab.net/d/msgid/discuss/d02acb3d-8655-4cb7-9085-519288569645n%40measurementlab.net.