HNY to all!

Seems to me that we often get distracted by nomenclature needlessly.  Perhaps it’s time to agree on the lexicon that should be used going forward so as to avoid such distractions.

Perhaps a place to start is “the technical facts”:

1) “capacity” is a property of a link (or links) that specifies the theoretically achievable maximum error-free transmission rate of data/information through a noisy channel (or channels, the multidimensiaonl version of the capacity theorem).  Yes, it’s much more complicated than that in general, however the basic principle is easy to understand. “You can only get so much water through a hose of size X with an applied pressure of magnitude Y.”)

2) “maximum achievable throughput/data-rate” of a channel is the maximum rate (always <= channel capacity) at which information can be exchanged in the channel as implemented (under all conditions).

3) achieved/measured “data rate” is the measured/estimated rate of information transmission (always <= maximum achievable rate” for that channel) in a channel under a given set of conditions.

4) “latency” is the amount of time it takes information to get from a source to its destination (there may be multiple destinations each with different latencies J).  Latency may (or may not) include the unavoidable consequence of the laws of physics that state information can not travel faster than the “speed” of light (actually the “speed” in whatever medium and by whatever mode the information is actually being transported)! Tin cans and strings have a transmission speed that depends critically on how hard each person at the end of the “link” are pulling on their cans! J The point is that when included, information transmission times from source to destination set a lower bound on the “latency” of that link/channel.

5) … (feel free to add more J

My two cents!

RR

-----Original Message-----
From: Starlink [mailto:starlink-bounces@lists.bufferbloat.net] On Behalf Of jf--- via Starlink
Sent: Wednesday, January 4, 2023 11:20 AM
To: Dave Taht
Cc: Dave Taht via Starlink; IETF IPPM WG; libreqos; Cake List; Rpm; bloat
Subject: Re: [Starlink] [Rpm] the grinch meets cloudflare's christmas present

HNY Dave and all the rest,

Great to see yet another capacity test add latency metrics to the results. This one looks like a good start.

Results from my Windstream DOCSIS 3.1 line (3.1 on download only, up is 3.0) Gigabit down / 35Mbps up provisioning. Using an IQrouter Pro (an i5 x86) with Cake set for 710/31 as this ISP can’t deliver reliable low-latency unless you shave a good bit off the targets. My local loop is pretty congested.

Here’s the latest Cloudflare test: