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Comment by ls65536 | Hacker News Reader

The asymmetry between download and upload speeds on cable connections is really awful in recent years. I see advertised download speeds like 300 Mbps and 1 Gbps available in many places, but the upload speeds seem to never exceed 30 Mbps around here (which is just 3% of the download speed at 1 Gbps!). Having something like 250/250 Mbps symmetric available would be overall more preferable than 1000/30 in all but the most extreme download situations, in my opinion.

I suppose maybe the cable networks are more optimized for average user behaviour (far more download than upload), but maybe there's also a fundamental limitation with the cable infrastructure that prevents faster uploads, perhaps to do with cable's legacy delivering television broadcasts? Whereas with fibre, almost everything I've seen available comes with symmetric speeds by default.

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The major reason that upload speeds tend to be far lower is that they are the lowest part of the spectrum on a cable network. As everything on a shared cable network is receiving everything else, encryption and noise filters are imperative. The higher the frequency of your noise, the more likely it is to cause issues on the rest of the hardware. There are high-pass filters all over the coax network to ensure that nothing over a certain frequency is able to get out on the network and screw things up for other customers. In order to expand the bandwidth by making the coax frequency pie larger, CATV providers would not only need to replace everybodys equipment to ensure it could handle the increased noise but also check every single meter of cable to find and remove all the high-pass filters.

A high-pass filter removes low frequencies, I think you mean there are low-pass filters.

I require symmetric since I upload a lot, plus I am on videoconferences frequently. I'd personally rather go for 100/100 than gigabit/something less than 100.

DOCSIS 3.0 (I think that's the latest) allocates a particular ratio of download vs upload frequencies, so even when speeds increase the asymmetry is still the same. I heard the next version of DOCSIS might change that though. Ideally there'd be enough fiber to not require DOCSIS anyway, but I don't have my hopes up for that.

Hopefully with a lot more WFH arrangements people start demanding symmetric connections. But

Most video conference uses ~4Mbps for your video feed going out. It is more likely you need 100Mbps upload for doing backups or uploading photos or home videos etc. For a household with 2 people working from home and also watching a ton of streaming content, 50Mbps up/down would be just fine, if you can get it reliably.

Anything more than that, especially in gigabit range is just gimmicks, IMO.

Totally agreed. Reliable 30 Mbps is enough for me and my wife to simultaneously join Teams or Zoom video calls without issues. It's enough even when our preschooler wants to call a friend on Zoom at the same time, which happened once. And it's enough to watch Netflix in HD on two screens at once.

Here in Northern NJ Comcast is a quite reliable broadband provider... but in the almost 18 years we've had their service the download speed has risen to 225 Mbps, while the upload speed has remained at around 5 Mbps. In practice this doesn't seem to matter much. I assume they could potentially add additional upstream frequencies but I doubt they get many complaints about it, or that very many of their customers are even aware of the asymmetry.

Switch to their business class offering if you need the upstream. I'm also in northern NJ and on 200/20 tier. There's no technical limitation on that bandwidth restriction so long as you have a docsis 3 modem or later that can bond multiple upstream channels.

However, there was a technical issue I had some months ago with a faulty Arris modem provisioning file that disabled upstream bonding across most of their models. It took an email to the CEO to sort it out (after a Reddit and DSLReports post on the matter).

How did you figure out the root cause? Usually you can't fetch those files yourself.

I bought 3 different Arris modems and they all bonded upstream until activated on the network through comcast's walled garden. Once activation was run the upstream sync light changed to show it was no longer bonding upstream. If a deactivated one was plugged in, again it would bond.

Previously I had been on a 50/10 tier and when the new business class tiers were released they blamed my trusted old SB6121s for being too old, so I bought 2 newer ones in the SB series and had same issues. After writing the CEO and CC'ing all the techs I spoke to and including links to the threads they gave me a direct engineering contact that confirmed the issue. For the trouble they credited me out 2 months of service.

It's market segmentation. You can get symmetric cable, but you have to pay for the business service

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