Hacker News Reader

Comment by plantain | Hacker News Reader

DOCSIS 3 (from 2006) can do 100/100 over cable - it's the decision of the provider not the technology.

It's at least somewhat inherent to the technology. DOCSIS download channels are shared among subscribers; upload channels are allocated exclusively per-subscriber. This architecture provides economic incentives for the provider to provision asymmetric circuits rather than symmetric ones.

100 Mbps up requires expanding the uplink band from 5-42MHz to 85MHz. That requires changing outdoor components like amplifier and filters, and upgrading millions of cable TV boxes, splitters and modems inside customers' homes. The combined cost of hiring more technicians and buying boxes might approach the cost of upgrading to fiber. Altice USA decided to skip DOCSIS 3.1 and start dragging fiber.

Which is all stuff they are doing anyway. Cable modems, even when not integrated with wifi don't last more than a couple years before someone adds a couple more channels, or tweaks the spec. Etc, Docsis 3.1 modems were available in the local best buy for probably 5+ years before my cable company would even provision them in docsis 3.0 modes.

They might have some excuses with the amps, but again, those can be upgraded as they age out/die too. This was the excuse 20 years ago when the amps didn't allow any upstream signals through in many areas. If a cable company hasn't been preparing/slowly rolling out new equipment as soon as the specs are available that is their own fault. Like any other technology you either get on the train, or you get left behind.

Beyond that it's pulling from a finite pot. Every Hz you allocate to upstream is one less Hz you can allocate to downstream.

Fiber doesn't have this constraint. It's trivial (and common) to deploy a pair to each premise, but, even if you don't want to do that you can shine light in both directions on the same piece of glass and reasonably* run a terabit across a single fiber (not a pair).

This is partly incorrect. Near the beginning of using data over coax cables the network architecture design dedicated more frequencies to getting data to your house as opposed to you sending data out. This was done because the initial network design was that they would send massive amounts of data to you as images and you would only send small amounts of data requesting paper view or other channel/media options.

All components through out the network rely on what came before.

Reply on news.ycombinator.com