Imagine how many relatives and friends of that guy go like: "hey you are good with computers, can you have a look at mine? its working weirdly with this and that!"

Working for an Australian ISP as a Technical Support rep myself, I feel like I have some input on the topic of this episode. You've essentially explained in this episode, very succinctly how exchange congestion occurs. On the note of ISPs "getting away with selling more than they can provide" (heavily paraphrasing) often it's not that bandwidth is oversold, more that the Infrastructure is installed for a Suburb and it's requirements, only for new housing settlements and the like to increase the load. To that effect, the options to resolve this would either be to have an enormous overhead on bandwidth, and provide way more than required in case of future congestion issues, which would cost more to install and likely drive up plan costs across the board. Alternatively, the other option would be to install the required infrastructure (with some overhead of course) and further upgrade across a State/Country as required, which blows out restoration timeframes for congestion events. Neither option is really smiled upon. It really is a balancing act as far as I understand it, and that's why the load balancing explained in this episode is so important. Not only to ensure you get the bandwidth you need when you need it, but make sure that the cost of maintaining such a network doesn't bite the consumers in the butt at the same time. Also worth noting I'm not a US Citizen and do not know how different things are across the pond.

Instead of saying "100 mbps", why don't they say "max 100 mbps, with a guaranteed min of 10 mbps" or something? That would be so much more honest.

The illustration of Poisson distribution at 4:00 gave me a chuckle. Nice one

Prior to fibre optics, when the voice network prevailed, stat muxing was necessary because trunk line and CO costs increased linearly with demand. Not so with glass fibres and modern electronics in routers. Not only is there a lot of dark fibre out there resulting in unused capacity, there are technologies like WDM that can put orders of magnitude more data across existing fibres. Rather than optimizing network design, stat muxing is currently used as an excuse to extract the maximum amount of money out of consumers at the ISP level, not because network capacity is a scarce or overly expensive resource.

Thank you for eschewing the wadsworth constant by immediately answering the question in the video's title.

i like the beginning of the video with the word "because" :)

Personally over the years I have adapted my Internet usage to be heavily weighted to the least busy times. 2am to 5am is my favorite time to get lots of Internet stuff done. I'm pretty much certain to get my full advertised bandwith.

Perhaps they should legally be required to advertise internet speeds as a range of expected speed.

Good video. Well explained so was easy to understand, and something I think we all have experienced. I have 30/2 and I get that speed 90% of the time. However, between 7-10PM I'm lucky to get 3/0.5.

This effect is obvious to anyone who has ever tried to use school wifi during said school's lunch break

We're subscribing to a 6/6 line, but never get more than 4/0.3 (5a.m.)... This video explained our problem in a great way!

12 view club :) Reminds me of that power grid video where they had to plan for the end of a television show because half of britain would put on the kettle afterwards and it could overload the grid.

If you think about it, the same concept applies to things like roads too. Only a small proportion of cars can be on the road at once, if everyone tried to drive their car at the same time it would just be a massive traffic jam.

I love this channel! :)

So, mechanically; how does paying for guaranteed bandwidth get me around the queues? Is my traffic prioritized in some way that prevents experiencing packet loss, or maybe I go through different 'VIP' queues?

The practice of loading more customers onto an ISP's Internet link than that link can support as if each customer were using their full capacity simultaneously is called "oversubscription." Back in the dialup days, ISPs commonly used a ratio of 10 to 1, but I don't know what common practice is for broaband these days. There's actually a measurement unit used in telephone traffic planning called the "erlang." Wikipedia has a half way decent treatment of that (in the Erlang (unit) article). There is a somewhat serious problem with Internet operations these days called "buffer bloat." It is the result of RAM prices falling quite a lot since the TCP was first engineered. Back when RAM was expensive, buffers were small, and relatively speaking a lot of packet loss occurred. That packet loss is what causes TCP to slow down its transmission of packets so as to use the links efficiently and to their capacity. However, when RAM got cheap, routers and the like were equipped and programmed with larger buffers in the belief that it was more important not to drop/lose traffic. But the resulting delay wreaks massive havoc with TCP's timing algorithms for adjusting transmission rate to match link transmission capacity. It's counterintuitive, but packet loss is actually good for the Internet, especially since such a large proportion of Internet traffic is TCP traffic. So unfortunately, buffer bloat tends to slow down apparent performance of people's connections in addition to oversubscription.

enlightening info!

An (arguably) bigger problem in the UK is crosstalk between phone lines on 'fibre' packages (VDSL2). In a DSLAM distribution cable, you can get 150 odd people's phone lines travelling right next to each other and the signals will interfere with each other. This means that if a whole load of people on your distribution point connect to a VDSL 'fibre broadband' service, even if they're not using the internet, your speed will be affected. A lot.

This is called overselling and nearly all service providers do this, going as deep as the virtual server market for personal websites. Many virtual game servers oversell each systems ram as well, in hopes that all of the virtual servers will not be using 100% of their ram all the time.

You can actually try if your isp (or something else) causes data loss: if you use the windows command line or linux shell and type for example "ping google.com" your computer sends message to google and waits for an answer. It will print how long it takes to answer and also give you an error message if your data got lost on the way. But I guess everyone knows that already?!?

No difference between land line trunking out of the local exchange and central office. There was typically only 10% capacity to make calls by subscribers in a branch exchange. When a notable event happened which would drive people to use their phones, you might get a fast-busy or warning message that all circuits are busy.

how did things go with the net neutrality thing? is it still recurring?

nice info on networks

And what about network shaping done by the ISPs ?

"you pay for the guarantee" No, you pay for the delivery of that ammount. if they can't deliver it, they shouldn't be allowed to sell it.

5 likes 0 dislikes and 2 comments 5+0+2 ＝ 502 and less than 302 views HACKED

So is this caused directly by the ISPs or the world wide fiber network ?

there is also the problem that the advertisements are done in bits/sec to get the number bigger even through everybody uses bytes/sec (ie: 100megabits/sec is actually 12.5megabytes/sec in fact)

awesome!!!!

You should have mentioned bufferbloat - if the buffers were smaller at the ISP level then the latency wouldn't be so bad even under congestion.

Got me wondering... When there is a big event of some kind and the phone network "collapses", e.g. thousands of people essentially ddos the phone network by accident. Is it really just like "packets" are dropped; in a protocol (humans calling) that doesn't handle dropped packages very well; or does the phone switches actually shut down as a "panic" response to too high demand?

They're making a satellite wireless for the whole world, cant wait till thats out!!

Did big cable companies and AT&T sponsor this video?

burst packages is not a tendency, is used that way from the bare start of the DSL connections atleast. It was done to obtain high speed, and not be LATENCY SENSITIVE. Any single FILE DOWNLOAD protocol works bursting package and tolerate to receive the ackanoledges LATER. So, it is not a tendency, it is how it works!.

"Statistical multiplexing" is just a fancy term for overselling.

Well - there's also QOS that can be applied too.

Illuminating!

Can you guys use a smoother marker or maybe a pen to write things? That scratching sound hurts!

I wonder if for moments when there are transients of demand then moments of quiet, if the ISP started storing sites like google and popular youtube videos based on the user's demand in a local HDD as a local cache. This way that can be accessed and deliver, say the otherwise redundant information. Maybe if multiple users are requesting the same, say, video stream, only one version of the stream is being pulled, and that goes out to the users, that way there is no possibility of redundant information using up bandwidth. I suppose the issue is technical (encryption of the packets, etc) or a general privacy invasion issue that would crop up otherwise.

Great for the Provider that they can garanty less than they advertise. I would wish that I could get what they would advertise 24/7, also I'd rather like a synchronous Internet connection (Upload bandwith = Download bandwith).

I have a question how does your ISP know at which speeds to send packages to you and vise versa? because when your computer is the bottleneck in a system using the internet, packets would get lost if your ISP would send them at full speed, and i doubt that they just send the packages over and over until you have received them. so does your computer send a "slow down" message or something?

Access to reliable, fast internet should be a human right even if it takes a lot of resources to accomplish that. Soon enough it will be as essential as air I'd be more satisfied to know how much internet they can give me in the worst case escenario when everybody is using bandwidth and when no one is so I know what to expect.

I use an ethernet cable through a router for my PC. The router is connected to the wall ethernet port.

So if have a regualy broadband and most people who share my isp aren't using it does that mean my internet speed will be 100mbps (If i bought 100mbps)

Why not develop a protocol so that it will decrease bandwidth rather than relying on cues and packet loss? Doesn't doing it this way slow everything down by a factor of 2 more than necessary?

how does FTTH affect the issues in this video? perhaps you guys could do a video about it ;)

ha 100Mbs ya right here (in Canada) with many people here in the building all various degree of moderate to heavy internet users, our landlord has had to go with small business option, and so ask us each to pay a little a month, and its only 50Mbs down, or so we're told of course

Why can't they just let people use extra bandwidth or throughput if their network isn't maxed out.. Maybe because the people they buy from (upstream) oversell, too.

What happens in reality: "lets charge our customers more money for less bandwidth and not upgrade our network!"

And that's why I love my ISP. 100/100 Mbps guaranteed bandwidth for roughly 15 quid a month. :)

Wouldn't it be much clearer for the customer to understand if ISPs sold/advertised average speeds? Then you'd be able to calculate on a monthly basis what speeds are reached and adjust the infrastructure so it delivers the promised average. What good is a 100mb/s connection to me if I am never expected to reach that speed? But if I knew I could expect an average of 50mb/s, I'd know what I pay for and would not be frustrated every time I check. But I guess transparency doesn't get you far in business...

Resource Sharing. . .if you dont wanna share. Pay more. . .

Can you guys talk about pointers

Why is it sometimes KZfaq will get VERY slow on my ISP, **ONLY** my ISP, but every other site is fast and I measure a good 5Mbps (paying for 10, but I live too far away from the DSLAM to really get good signal) and youtube buffers even at 144p! (seriously, I can load on 700Kbps-2.5 Mbps 3G a 720p video with only a little buffering at the beginning!!!) How can I prove that Centurylink is purposely slowing down youtube to a crawl??? or is it in fact some youtube IP selection problem thing where by chance the ISP somehow selects the slowest, furthest away server for youtube.com!

comes down to not being able to foresee when i want to use my internet, right? say i want to see every video from numberphile, when it comes out i might be at school and the internet is 'fast' but when i get home everyone watches stuff, so why cant there be a youtube 'app' that knows what i will want to watch because of my history and therefore caches the videos while the internet is 'fast' and thus give room for others at times of high usage? and i wont ever have to wait on videos to buffer as i have already downloaded them. i can even tell the 'app' what i want to watch next via the watch later list, so when i watch the precached videos it could load the ones i want to watch afterwards. maybe even connect to social media and preload the posts of my interest before i come home or leave the computer. now i have no clue how that could work, but it would be cool to not have to wait endlessly when i want to consume content

The worst enemy of ISPs are the major social events!.

Was I the only one not expecting to hear the word "suck" in his explanation? :P 1:47

That's why internet is so much faster after 1 am....

The whole "up to" thing is shitty enough as it is, but when they start suing/warning people who use a lot all the time or businesses that takes a lot of bandwidth then it's not okay.

This, to me, is just false advertising. An ISP should be able to give what they promise.

Kind of like how universities over-sell parking spots on-campus. The likelihood that all students will be on campus on the same day is slim.

I like the "UNISEX" tee-shirt :D

Just a thought. use users as p2p and internet as a file. more user better internet hybrid

As far as im concerned, if you pay for 100 mb/s, and you cannot provide that as stated, then it should be grounds for a lawsuit, especially when we pay them to upgrade their shit, and they dont.

Why are these videos 25 frames per second? I downloaded youtube center, and what

so basically what you're saying is that the internet slows down because it's not like a big truck, it's a series of tubes?

"The network provide makes assumptions..." Do you know what they say about assumptions? ;)

*it's

Well, so it's actually illegal what the companies are doing. They are lowering the maximum bandwidth on purpose.

Wow. Just like banks.

so that is why DDos'ing works right?

So.... ISP's need to build the infrastructure so they can actually support what they are selling? Getting more business but not building more supports to hold the business up...

Fortunately my 30 mb/s connection has 21 mb/s guaranteed.

*TL;DR* - that's OK; I don't know when reading became so reviled, but, OK, move along, no summary here (it wasn't worth reading anyway). _A random observation_ This all just seems like a clever way of saying that there is a false economy at play, and in order to disguise that fact they made false advertising legal. I'm not an ISP. One of the (many) reasons I'm not an ISP is because I know it's very complicated on many fronts, including load balancing and scaling. I am not skilled enough (or at all) to do the analysis and make the computations required in order to provide a workable operational model for an ISP. So, call me crazy, but I did not set up business as an ISP. Is it not reasonable to expect, even categorically demand without compromise, that someone choosing to do business as an ISP should be competent in the things that an ISP needs to do to operate? Including the complicated bits, like this? Yes, I know it's complicated, but you have actively chosen to set up in business as an ISP - you knew these problems existed before hand, they did not just suddenly occur anew out of nowhere as an impediment to your operations - so naturally, you are perfectly capable of dealing with this. Right? But, no, they're aloud to gamble on the balance of probability as a business model and plead that, 'it's complicated' when they get it wrong - frequently in my experience. Then, rather than deal with the fundamental shortcomings in their business model,they instead (successfully) lobby parliament to allow them to sell the service as, "*up to* 'n' MB/s". And with that semantic sleight of hand, they deftly abrogate all responsibility for the actual quality of their service, and sidestep any reasonable expectations that their service sold and advertised as "up to 'n' MB/s" need ever come anywhere close to actually providing anything like the 'n' in question - not just regularly, but ever, not even once. Because, it's complicated; but, also, charging extra, to avoid legal semantics, and get a verifiable measure of your quality of service as a guarantee, is a very profitable revenue stream.

A series of tubes...

Statistical multiplexing - "smuxing"?

So what if I use 100% of my internet 100% of the time?

The twenty-eight dislikers always have slow internet. xdddd

i always get more than i pay for and i am always at 100% upload and download

The Internet always slow

So that might be the reason why I can't really watch twitch during the evening times... Time to get a buissnessline I think.

You didn't even mention the more malicious possibilities of why your connection could be slow. We don't live in a perfect world; this video is far from complete.

it's

TL;DR Learn to torrent or download in advance of 5pm ! ! ! xD

Like a bank

pipnina 152mbps indicates virgin media, who use shielded coax cable, so crosstalk is pretty much non existant.

So what you are saying is, if someone comes up with a solution to this, they will be one rich son of a gun?

oh i hate the sound of this pen on paper.. it is really not made for that :D

I believe it is It's LOL

www.speedtest.net/result/3922611242.png My internet is always like this despite being on a 90mb/s plan

IINET is terrible, so much packet loss....

Yes son, that's how shitty (99.9% of all) ISP's work..sell lies to the consumer.

Its like a Ponzi scheme but with bandwidth

"Why traffic slows down when the roads are busy" or What a stupid question. Is there really anyone asking this? OK, people who don't know anything about the technology, but with the traffic/roads comparison, anyone will understand it.

Sorry, your video is probably great, but due to your constant use of permanent markers I must avoid watching. It's painful for my ears. I'm sure it's some phobia I am unaware of. Silly, I know but to me it sounds like nails on a chalk board.