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Comment by psim1 | Hacker News Reader

When I switched from DSL to cable internet several years ago, the concern I had was with upload capacity. To get to 10 Mbps upload speed, which I wanted in order to be able to do high-definition video conferencing along with other simultaneous internet usage, I had to order the 250 Mbps download speed. I recognize that I seldom use 250 Mbps download, but I can fill up 10 Mbps upload pretty easily.

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You are a minority 1% user who doesn't really show up in the statistics. Most likely your upload is classified as file sharing and you are probably seen as abusing your connection. There is a reason why uploads are so limited for consumers. You should get a business connection if you really need it for conduction serious business.

If you do online backups you better get the backup plan that will be coming soon from a range of supported backup providers. /s

Comcast Business operates on a 10:1 dL/uL ratio, at least here in Colorado. We have 300/30mbps, no option of 200/100 etc.

Could you get a dedicated fiber connection for your business? Those things cost a bit more.

Video conferencing isn't the only use for upload bandwidth. There are lots of other use-cases which are much more mainstream, like streaming, YouTube uploads, backups (lots of phones these days do photo/video backups automatically), photo sharing, etc. Downloads are still more common of course, but these days I'd say upload bandwidth gets used far more than it ever has in the past.

Every use case you’ve given are minority use cases or power users. I’d say less than 5% of subscribers do the above and most do not use a lot of upstream bandwidth. Most phones do the backups at night when most people are sleeping.

> There is a reason why uploads are so limited for consumers.

and that reason is that DOCSIS allocates more channels for down than up. and DOCSIS does that because that's what most consumers want.

Over copper it's easier to provide asymetric connections because the provider can better manage interference between different cables. When there's no interference problem it's only a question of allocating the bandwidth. Ideally the connection would auto-adjust and provide up to the full bandwidth in both directions instead of constant half/half or 0.9/0.1.

Yep. I have a 350/35 connection.

Are backbones usually heavily asymmetric? Or do the ISP's just have say, 10gbit symmetric lines that barely get used on one side, with the odd content host saturating?

Backbones are generally symmetric.

Without getting into super deep detail, on cable internet, there is a balance between spectrum allocated for Tv content, and internet bandwidth. The system will have a finite amount of spectrum available, which can be divided between TV content, downstream internet, and upstream internet.

Given that most peoples usage is mostly downloading, the CATV carriers allocate more spectrum/bandwidth to downloads vs uploads.

Any reason why can’t those be allocated dynamically and switched between upload/download? So your connection is still not symmetric, but at least your 350Mbps download speed can suddenly turn into 350Mbps upload, or be roughly evenly split in half if you’re both uploading and downloading?

I was pretty sure fiber was bi-directional so you can always saturate the same fiber with all upload or download based on demand. Copper wire can't do this so they use most of their last mile copper for download since that is what most people use the most of.

Yeah but my point is why can’t it do the same as Wi-Fi (since technically coax is just radio anyway) and dynamically allocate bandwidth for upload or download depending on usage?

technically possible, would require a ton of upgrades to the infrastructure to support such a thing, and probably just not worth the investment for these companies right now.

It possibly could be. It has been 15 years since I worked in the CATV market, so I'm not totally up to speed on the nuances of the latest platforms.

1) The filters and amplifiers that split upstream/downstream/video are typically hardware, tuned for specific frequency bands.

2) The cable is a shared medium (like wifi) so it’s not just a matter of what you’re doing, but what everyone else is doing.

Also, most downloads can be cached through CDNs near the requester, while uploads can not.

ADSL2+ uses frequency division duplexing (FDD), ~9:1 ratio (50/448 bins). DOCSIS up to 3.1 is also FDD. Typical EuroDOCSIS 3.0 modem deployments work in 8/4 (max 400/100 Mbit) or 16/8 (max 800/200 Mbit) channel configurations.

Finally 'full duplex' DOCSIS 3.1, renamed to 4.0, promises up to 10Gbps symmetric transfers thanks to echo cancellation (V.34 dialup modem says hi). Of course we barely switched to 3.1 and its unlikely cable networks will jump on the 4.0 bandwagon any time soon.

4:1 is a reasonable ratio for consumer connections, at least. I'm sitting here on a DOCSIS 3.0 modem but it's set up as 10:1. And going up a tier doesn't increase upload speed at all.

The transmission lines are half-duplex on a channel by channel basis. At any given time you can either use a channel for upload or download, but not both. And usage is very asymmetric. It's more efficient to thus allocate more channels for download. Otherwise, you'll have unused upload channels while the download channels are saturated.

It's mostly about the connection from the local node to your house, not the backbone.

Ultimately I think this is an outcome of asymmetric price elasticity:

People who are downstream limited tend to be on the consumer side. Even if they might be willing to pay more for higher bandwidth it's more a convenience than something they really need. So in order to actually get them on a more expensive tier, the ISP has to offer an upgrade with a relatively high bandwidth per dollar difference in downstream.

People who are limited primarily by upstream however tend to be be more of the productive side and, if what they have is not enough, there is probably some form of urgency for more. They will jump on higher tiers for much smaller upstream deltas than their downstream-limited counterparts.

I don't know if there is an actual technological or logistical reason forcing ISPs to only offer one up/down ratio per price tier, but if they offered selectable asymmetry or symmetric, they would either get less money from downstream users (not attractive enough to upgrade) or from upstream users (problem solved at a lower tier).

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