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Can you explain a bit more to help me understand how 1gbps is enough for 500 customers? I would have imagined that during peak times, you might have, say, half

Can you explain a bit more to help me understand how 1gbps is enough for 500 customers? I would have imagined that during peak times, you might have, say, half of your customers streaming video at the same time, which is only 250KiB/s for each customer before any overhead. How is the connection shared between customers? Can one kid downloading blu ray rips over NNTP eat half of that 1gbps? What's the price range for the end customer?

bluedino 10y ago
Each customer doesn't get the full 1Gbs - you'd oversubscribe them at a 10:1 to 200:1 ratio, and you might only offer say 40mbs.
sathackr 10y ago
A conservative oversell ratio is 4:1. I've seen them as high as 100:1 in older communities. Also, counterintuitively, with some exceptions, the higher the speed you promise, the greater your oversell rate can be. 4:1 on a 1Gb connection gets you 4Gb/s. Divided into 500 connections is 8Mb/s per connection. I've fought this battle before on HN, but everyone does not need a 150Mb/s connection. Yes, some people do, but most do not. I haven't checked recently but last time I looked an HD Netflix stream used about 5mb/s of bandwidth. I think your assumption that half of your subscribers would be streaming video is a bit on the high side -- in some communities it may be accurate but not most by my observations. For planning, I would say 10%, maybe 20% tops. If you're selling a 100Mb/s to residential customers, you could probably even oversell at 8:1 or higher, since their usage compared to total will be much lower. Your oversell rate will also heavily dependent on how much your base is commercial/business customers. Residential use is peanuts during business hours, business use is peanuts during residential hours. So you can almost oversell by a factor of 2x over your normal rate for business vs residential, and it's also been my experience that as a whole, businesses use far less bandwidth than residential. There are some outliers that will really skew your numbers. If you sell a 100Mb/s connection to a college that is providing it to their dorms with 1000 students, you can almost guarantee they will be nearly continuously saturating their connection. Edit: adding answer for 2nd question. For the most part, without any throttling or queuing users downloading will get an equal share of the bandwidth available. 10 simultaneous users would get 100Mb/s, 100 simutaneously downloading users would get 10Mb/s each. Upload is what will kill your bandwidth. One user saturating your connection with outbound traffic will slow everyone down. But most ISPs queue/rate limit customer traffic. It's integrated into most commercial wireless equipment and routers. On top of that, depending on what technology you use, CPE(customer premise equipment) generally doesn't have the ability to pull more than 100mb/s. Some are lower, a few can go up. I'm not a Mimosa fan yet, but there is a guy woth a usually well informed blog[1] that sings their praises in providing multi-hundred megabit service to residential customers. My experiences with Mimosa gear have been such that I can't recommend them right now, but they have potential. [1] http://muniwireless.com http://muniwireless.com
- grahamburger 10y ago
  Yup, this is exactly right. The way I usually look at is this - if I put 100 customers on a link that had unlimited bandwidth and then watch the max usage on that link, how high will it spike and for how much time? The current situation is that 100 customers won't spike to more than around 400-500 megs for more than a few minutes a day. But that number goes down the more customers you aggregate, to the point that 600 or 700 customers won't spike to more than 1gpbs for more than a few minutes a day. So if you buy a 1gbps link to serve them, you're only slowing things down for a few minutes a day.
- gabemart 10y ago
  That's a really informative answer, thanks very much

bluedino 10y ago

Each customer doesn't get the full 1Gbs - you'd oversubscribe them at a 10:1 to 200:1 ratio, and you might only offer say 40mbs.

sathackr 10y ago

A conservative oversell ratio is 4:1. I've seen them as high as 100:1 in older communities. Also, counterintuitively, with some exceptions, the higher the speed you promise, the greater your oversell rate can be. 4:1 on a 1Gb connection gets you 4Gb/s. Divided into 500 connections is 8Mb/s per connection. I've fought this battle before on HN, but everyone does not need a 150Mb/s connection. Yes, some people do, but most do not. I haven't checked recently but last time I looked an HD Netflix stream used about 5mb/s of bandwidth. I think your assumption that half of your subscribers would be streaming video is a bit on the high side -- in some communities it may be accurate but not most by my observations. For planning, I would say 10%, maybe 20% tops. If you're selling a 100Mb/s to residential customers, you could probably even oversell at 8:1 or higher, since their usage compared to total will be much lower. Your oversell rate will also heavily dependent on how much your base is commercial/business customers. Residential use is peanuts during business hours, business use is peanuts during residential hours. So you can almost oversell by a factor of 2x over your normal rate for business vs residential, and it's also been my experience that as a whole, businesses use far less bandwidth than residential. There are some outliers that will really skew your numbers. If you sell a 100Mb/s connection to a college that is providing it to their dorms with 1000 students, you can almost guarantee they will be nearly continuously saturating their connection. Edit: adding answer for 2nd question. For the most part, without any throttling or queuing users downloading will get an equal share of the bandwidth available. 10 simultaneous users would get 100Mb/s, 100 simutaneously downloading users would get 10Mb/s each. Upload is what will kill your bandwidth. One user saturating your connection with outbound traffic will slow everyone down. But most ISPs queue/rate limit customer traffic. It's integrated into most commercial wireless equipment and routers. On top of that, depending on what technology you use, CPE(customer premise equipment) generally doesn't have the ability to pull more than 100mb/s. Some are lower, a few can go up. I'm not a Mimosa fan yet, but there is a guy woth a usually well informed blog[1] that sings their praises in providing multi-hundred megabit service to residential customers. My experiences with Mimosa gear have been such that I can't recommend them right now, but they have potential. [1] http://muniwireless.com http://muniwireless.com

grahamburger 10y ago
Yup, this is exactly right. The way I usually look at is this - if I put 100 customers on a link that had unlimited bandwidth and then watch the max usage on that link, how high will it spike and for how much time? The current situation is that 100 customers won't spike to more than around 400-500 megs for more than a few minutes a day. But that number goes down the more customers you aggregate, to the point that 600 or 700 customers won't spike to more than 1gpbs for more than a few minutes a day. So if you buy a 1gbps link to serve them, you're only slowing things down for a few minutes a day.
gabemart 10y ago
That's a really informative answer, thanks very much