Oversubcription is the norm for residential customers. And it makes sense in the way that you don’t download at max speed 24/7 content from the internet and you don’t upload either. The usage tends to be: access an article/picture, then read/watch, rinse and repeat. So for those few seconds/minutes you don’t use the internet connection.

When people watch a movie on Prime/Hulu/Netflix, sure, you have constant usage, but 4K streaming is less then 20Mbps…

Most people never use the full amount of even the lowest guaranteed availabke bandwidth per customer.

I am more concerned with underutilization. I am specifically looking at Disney Plus delivering barely 720p to browsers no matter the available bandwidth (while easily streaming hdr 4K to Apple TV on a same network).

init7's post about overbooking is somewhat misleading. As their customer, I think it's more about how overbooking hurts them as a provider, not just us end-users.

I used to have a 10Gbps connection through Swisscom (Switzerland's de-facto main fiber provider) using XGS-PON. My internet service was from a third-party ISP, but the underlying infrastructure was Swisscom's. My speed tests consistently showed around 8Gbps up and down (10G minus XGS-PON overhead)

Init7's issue is that XGS-PON requires specific equipment and network access from Swisscom. Swisscom charges them for this, and it can also create other limitations (I remember problems with IPv6). With P2P fiber, init7 can connect directly to their own equipment in a local hub, giving them more control.

For most users, the occasional latency spikes or brief speed drops from 8Gbps to 1Gbps aren't a major concern - at least I never had serious problem with FPS games where latency matters.

I wish there was more concerted effort being made to utilize the idle upstream in residential connections. Something like bittorrent.

The average consumer fibre install in a building needs to cater for weekend mass netflix watching. There is no equivalent for up. It's just sitting idle.

Think we could make a decent dent in the amount of datacenters needed if that was solved.

I worked at a large ISP and telco in my youth, and ofc this is how its done, its been this way forever, and is also basicly how phone networks where and are built, because you know that everyone is not going to call everyone at the same exact time, so you use an Erlang B calculation to figure out what you actually need..

For reference ths ISP i worked for, that was pretty damn big, started out with 40 modems, and that lasted a looong time..

Btw. Biggest issue with traffic when i worked there was the advent of p2p sharing, that required massive upgrades

Overbooking used to be called the "contention ratio" back in my day when I was working with Nortel CVX 1800 modem racks (and before that too with older, crappier, less dense racks running off E1s or even ISDN).

A full rack of 1000 modems at 56kbps means 7Mbps bandwidth needed to feed the box. We had ~20 racks, so we'd need (in theory), 140Mbps up to the internet to service them all at a 1:1 contention ratio. In truth, we had ~35Mbps - a very generous 4:1 contention ratio.

Why does it work? Well, when you're browsing the web, you load a page (and use bandwidth), and then you read it and don't use bandwidth.

For every second of download, you probably have 30+ seconds of idle bandwidth while you're reading those emails or web pages or whatever - and yes, one manager was pushing us to get to 30:1 contention, which was industry norm at the time - so this actually works fine. One colleague who had worked at a major competitor told us they regularly pushed to 100:1 and no customer seemed to care. We actually benchmarked them (and a bunch of other ISPs), and yeah, was a little slow at peak, but actually not awful most of the time.

The problems started to come when people wanted to max out their connection more because of an evolution of applications, technology and expectations (in short DSL, the rise of P2P services and people "being online" more was a triply whammy), and so more customers wanted to use every bit of bandwidth every second, all day, every day. In the UK, even the BBC was being asked to do something because the launch of iPlayer absolutely crucified a lot of ISPs.

I was out of the game by then, but approaches seemed to include citing breach of acceptable use policies (very unpopular), blocking certain services (one of the reasons why the major ISPs block TPB in the UK), or - in at least one case I heard about - traffic shaping those "greedy" customers until they went away. If you throttle someone who is paying for 10Mbps down to 1Mbps, because they've been taking all 10Mbps 24x7 for the last three months, they'll get frustrated and leave your service with the only real cost being a bad online review you can blame on backhaul network/bad copper/bad modem, and which is drowned out by other "normal" users claiming you're a great ISP. And yes, I do know of at least one ISP who did this regularly - a former staffer told me a few years after he left.

I've always known that internet is oversubscribed (it's the only way to do it, really), but I'm still surprised just how far they have gone.

The 1:32 split of XGS-PON is already bad enough - especially with providers selling 8Gbit connections - but a 32Gbit uplink for 4000 customers?! If GunBlastGame 5000 releases an update, the 5 kids from the same school all starting an update when they come home is already enough to saturate the entire neighborhood's connection. I was expecting something more like 400Gbit for a city of 75.000 - less total capacity, but far harder to saturate at a local level.

I think one interesting topic missed in the article is how the GPON network is actually constructed. Some providers have the splitters placed close to the customers, while others have them placed close to the upstream connection. Having splitters close to the customer means you need far less fiber and can easily add an extra home, but the customer is always stuck with their neighbors - it's expensive to add extra capacity. Having a centralized splitter cabinet makes it way easier to patch a customer onto another splitter - or even give them a dedicated connection. On the other hand, you have to lay far more fiber as every home now needs its own connection to the cabinet, and adding a new home can become quite tricky if you haven't planned ahead.

i didn't realize fiber could be overbooked similar to cable. I had a 3gbit plan but downgraded to 500mbit because barely any transfers would go over 300mbit during the day. I kept thinking the servers I download from are overloaded, but it makes more sense my provider overbooks than the entirety of the internet being slow... time to put in some complaint calls during peak hours!

I've always wanted to know this. The local provider keeps selling nominal 1GBit/s (to the DSLAM) but does the uplink hold up to this if every endpoint is saturating its connection?

As a consumer I always assumed the network capacity scaled exponentially at each aggregation point. Sounds like it's much less than one would assume given the number of consumers...

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> PS: Most complaints about “slow Internet” are due to poor WiFi quality.

The exception to this is Deutsche Telekom. They demand atrocious pricing for peering and only have very limited peering at DE-CIX and BCIX - 20 Gbit/s at DE-CIX [1], compared to the 2x600 Gbit/s that, say, Vodafone has.

The result is massive complaints about peering with virtually anyone, even the big dog Cloudflare [2].

I recommend every fellow German to subscribe with a regional provider - in Bavaria for example, book a M-net connection. The last mile will be handled by Telekom who are subcontracted by M-net or whomever else you choose, but there's government-regulated exchange points so you bypass Telekom's shitty peering.

[1] https://www.golem.de/news/de-cix-nutzer-leiden-unter-geringe...

[2] https://telekomhilft.telekom.de/t5/Festnetz-Internet/Peering...

Yeah, this was noticeable during lockdown when everyone was doing video calls while working from home.

This was one more reason why I was skeptic about VR, the infra isn't there for mass adoption as it was marketed at the time.

they've oversold the flight!