>Blizzard used to use Bittorrent in some of their installers/updaters a while ago.

Yes, WoW used to have bit-torrent based update.

>Many residential connections are heavily asymmetric.

this is a US centric-view, though. For instance I have 300Mb up/down. At least for most of the Europe (and I suppose Asia), it's pretty common not to be restricted in any way.

I could leave a bit-torrent client non-stop and won't feel it. Like I've said: alas. There is some stigma associated with p2p/torrents.

I have very rarely seen symmetric broadband plans available in Finland. In the past I've had 10/1, 24/1, 100/10 and now I have 1000/100. With ADSL connections being asymmetric was basically necessary because the bandwidth is so limited - I think most consumers would prefer 24/1 over 12/12. With fiber I think it's more about market segmentation: ISPs want businesses to buy significantly more expensive symmetric plans.

Not sure where you are in Europe, but in Germany you have to search a bit to find a residential ISP with symmetric bandwidth. Mine is 50/10.

Asymmetry is the rule in my country for both copper and fibre lines, although it's less pronounced with fibre. Symmetric lines are a specific business option.

> At least for most of the Europe (and I suppose Asia), it's pretty common not to be restricted in any way.

In the Philippines, 15 Mbps down / 3 Mbps up ADSL with a static public IP is not something that a foreigner could easily buy. Globe Telecom in Cebu asked for evidence that I have sufficient income to pay for this (2600 PHP per month), and their rules only allow documents from the Philippines, so my bank statement was rejected. I had to talk to their higher-level manager to negotiate an exception. And their default router has 2 seconds of bufferbloat, so I bought a TP-Link Archer C7 and installed OpenWRT to compensate.

> this is a US centric-view, though

I live in Europe and I have a 1000/0.5 Mbit/s connection.

My gut feeling says you have a 200/0.5Mbit/s connection at maximum, because just from watching some download monitor out of the corner of my eye while downloading something with 100Mbit/s requires about 250kbit/s ACK packets in the upstream.

No more ACKs? No more DL!

No, I can still hit (almost) 1 Gigabit on the downlink. DOCSIS networks are so heavily asymmetric, they take special measures (ACK compression) to get around that!

Interesting... never been on Cable/DOCSIS.

That seems very atypical. As the link capacity ratio goes past 10:1, even for typical dowloads, speed starts to be limited by the ability to send requests, or even TCP ACKs.

I've seen 20:1 offers on cable providers, but it's mostly marketing BS, as you're unlikely to get full download speed in most circumstances due to upload limitations.

True - my nominal bandwidth (i.e. what I pay for) is 1000/50.

I do reach the full downlink speed though due to (presumably) ACK compression in the modem and ACK synthesis/reexpansion in the CMTS. You are right that otherwise such a high ratio would not be feasible with TCP.

Plain single-stream download-only TCP should fit without compression, probably even without Delayed ACKs.

IME, the line starts to choke when you actually want to send requests and they compete with ACKs and your internet stutters and crawls in both direction. Though that was with a slower connection - it's harder to fill a bigger pipe.

BTW, is the ACK compression counted for consumers benefit?

This is not the standard at all in Europe, maybe that's the standard in your specific country?

I have lived in quite few countries, travelled as well. Someone mentioned Germany (and Bavaria) - indeed, it had one of the worst inet couple of years back. OTOH, Austria was totally fine.

"It's fine" is a different statement from "up- and downlink bandwidths are heavily asymmetric", no?

While asymmetric connections make sense for many residential use cases, P2P is not one of them.

Your claim was that the lines were symmetric and "unrestricted". Neither are the standard unfortunately.