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Message-ID: <28d9d0df-7f0a-b679-f648-8f7bfd689f5a@ionary.com> Date: 13 Feb 2022 11:22:21 -0500 From: "Fred Goldstein" <invalid@see.sig.telecom-digest.org> Subject: Re: Verizon Fios begins offering multi-gig home internet speeds in NYC On 2/12/2022 12:28 PM, Bill Horne wrote: > The provider's fastest plan is available in select areas of the city > and will be rolled out to additional markets later this year. > ... > > I'm also curious about how a line that tops out at 940 Mbps can be > labelled "Gigabit" when it obviously isn't: let's see, I'll grab a > virtual pencil ... > > 940 divided by 1,000 is 0.94. > 880 divided by 1,000 is 0.88. > > So, Verizon's "Gigabit" service, according to Cnet, is only 94% of a > Gigabit on download, and only 88% of a Gigabit on uploads. > > Bill Horne Speeds are measured using the burst rate of the physical layer. GigE essentially transmits a bit in a billionth of a second. But usable capacity is always lower than the burst rate. There is protocol overhead, like the packet headers, and sometimes some mandatory wait time, like for upstream arbitration. So depending on how it's measured, it's always somewhat below the burst rate. The FCC rule for compliance with CAF/RDOF obligation is to net 80%. -- Fred R. Goldstein k1io fred "at" ionary.com +1 617 795 2701