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by 2bitencryption 983 days ago
Interesting, how many seconds of 2Gbps transfer do I get before I reach my monthly cap and they start throttling me?

Jokes aside, I'm curious how this is even possible over decades-old cable. I get there's a new DOCSIS standard, but I'm less interested in the protocol and more interested in the simple physics of it. How can a simple coaxial cable cram so much bandwidth?

2 comments

You could spend your full terabyte in just over an hour (4000 seconds). Your highest sustainable monthly average bandwidth would be just over 3 mbps.

Source: happy ex-Comcast customer

Happy ex-Comcast customer as well (as much as it pains me to say it, ATT has actually been pretty good to me with their fiber) but your numbers seem to go against a 1 TB limit but even the gigabit pro plan already includes the "unlimited data" option which allows you to go well past that. They never would say what exactly "fair use" was but it was at least above 15 TB/m from what I could tell of not getting kicked off.
Oh interesting. When I was in California, my 1 Gbps plan came with only 1 TB of bandwidth. They did sell "unlimited" as an additional upgrade but IIRC it was $50/month.
> How can a simple coaxial cable cram so much bandwidth?

A large amount of spectrum to work with and a high spectral efficiency. Wikipedia lists DOCSIS 4.0 as having 1.8GHz of bandwidth, and DOCSIS 3.1 as ~10bits/Hz. Assuming DOCSIS 4.0 is as least as efficient, thats about 18Gbps.