That's easy to claim, but there are a lot of places where everyone is surrounded by everyone else's wifi routers. If you have 9 routers that you share walls with and even more that can reach you, wifi starts to break down, but people will blame their service provider.
I've been there a bunch, my colleague has lived there. We work in the telco area. My own experiences I would question, his I don't.
It's oversubscription.
Can I provide citations or proof? No. That's extremely hard to do with oversubscription in general, no telco will admit their exact ratio without being forced to. Sometimes you can reverse engineer it from peering relationships, but that doesn't allow identifying bandwidth constraints on medium haul.
You said that already, but repeating something isn't evidence. Oversubscription would be something that happens with cable internet on a node by node basis, so to say the problem is one thing and only that doesn't make any sense. Not only that but people will sign up for hundred megabit to gigabit internet but they only really need to watch some streams that use 3mb each.
You can actually figure out oversubscription if you ping nodes, especially over time.
There are more factors like international bandwidth, lack of caching servers in smaller countries so bandwidth has to be international, cable signal levels etc.
None of these come close to wifi contamination. If you have two neighbors trying to watch tv over wifi and you're trying to watch tv over wifi, you're sunk. Now take that to being surrounded by a dozen people, all watching tv over wifi and all watching videos on phones and tablets.
Unless someone is in a house, more isolated from their neighbors it is going to be a much bigger problem for almost everyone.
You can say 'oversubscription' because you're buddy said that, but even that can have some truth while still being a marginal issue next to the real problems. Even in places with great internet, people get a single wifi router, put all their computers and TVs on it, then blame their ISP.
You seem to be making arguments with significantly less of a connection to the actual scenario being discussed. And you're explaining oversubscription to 2 network engineers, one of them having presented at APRICOT and APNIC.
I guess I should've focused less on oversubscription and made clear that we know it's not spectrum utilization. For that, we have the equipment to measure, and we did, and it's not the problem.
For that, we have the equipment to measure, and we did, and it's not the problem.
It has been a problem for basically everyone living in apartments that had network problems that I've seen. If you measure at the wrong time it's going to look fine. You have to be there when people are watching video over wifi.
Again, just because people can't get their full bandwidth, it doesn't mean oversubscription is the actual bottleneck.
Dude, how oblivious are you. You're {man,nerd}splaining. Hard. Did you miss the "network engineer" part? Do you think our first step in debugging performance issues seen on wifi would be anything other than grabbing a cable?
I get that you don't want to actually confront what I'm saying by pulling out a label and doing the appeal to authority routine, but that isn't real evidence or information.
You're still ignoring that two things can be true, but it doesn't mean they are both equal contributors when you take a birds eye overview of entire countries.
You also aren't explaining why wifi wouldn't be the primary bottleneck when you're surrounded by dozens of routers with shared walls and everyone is watching multiple video streams.
If you go into an apartment 10 floors up anywhere with internet you see dozens of wifi networks.
Not a network engineer by any measure - but I think if it was wifi contamination, it wouldn't get worse in the evenings. The routers are on 24/7. Thoughts?
That's why professionals don't call this "wifi contamination", we call it spectrum utilization/congestion. The problem isn't the number of wifi APs, the impact of beacons (i.e. idle APs) is, while not zero, quite limited and only visible in extreme cases. The actual problem is traffic, which consumes available spectrum when being carried.
It's a factor of RF bandwidth, time and space. With some non-obvious parts:
- setting your TX power too high makes you consume spectrum in a larger area, harming your neighbors. Don't yank the TX power to maximum just because it "feels" like that should be better; there is no difference between MCS (= speed/rate) 11 with 10 dBm headroom and MCS 11 with no headroom, you get ≈120Mbit either way.
- conversely, using old APs, devices, or stretching the wifi connection too far consumes excessive spectrum since you'll get a bad data rate and use much more time to convey the same data. Due to this, a repeater can in fact improve performance for devices not even using it, by getting rid of low-MCS traffic.
- don't use wide channels when you don't need the performance. A 160MHz channel means 160MHz width of picking up interference. While chipsets are somewhat intelligent about this, if you're fine with ≈200 Mbit (single MIMO stream) there's no point in going wider than 40 MHz.
- multicast is death. It's a very common wrong belief that wifi requires you to send multicast traffic at the lowest possible rate. It doesn't, but almost all low-end implementations are lazy and do just that. "Lowest possible" in this case means the lowest rate the BSS configured to support. If you have 802.11b enabled, that's generally 1 Mbit/s. Disable that, and you get the lowest 802.11n rate, which is ≈6.5 Mbit/s. If you need to deal with a lot of multicast, disabling some low MCS might also be worth it to raise that even further, but then those MCSes are not available to cover far-away devices anymore. But then again you may not want that to begin with (see above).
- it's highly dependent on building characteristics; thick stone/steel walls block much more RF energy than drywall or wood.
- if you can, just use cables. If it doesn't help you, it might still help your neighbors.
So… yeah, a lot of people consume media in the evening, and that does make it much worse.
Why not? People come home and start using their internet. They watch TV over wifi, use their PCs, watch videos on their phones, everyone uses what they have at the same time.
