Why do ISP's not give faster upload speeds?

[Cracktic]

This is something that has confused me for a long time. Why are ISP upload speeds so much slower than download? The canned reason is often "Well users spend more time downloading than uploading so networks have been optimized for download speeds by design". This is a common theme with cable and dsl. Often times in contrast, I see that fiber connections are synchronous (i.e. giving the same upload speed as download speed) .

I also feel like this "optimized by design" explanation is a cover for laziness or something else like ISPs are somehow using that bandwidth that isn't allocated to user upload connections for something else. I really don't know how cable and dsl infrastructure works as far as what determines speed capabilities so I'm guessing. I also have to wonder why fiber connections aren't "optimized by design to provide faster download speeds" and instead give synchronous speeds.

[corrado33]

Higher upload speeds are reserved for the more expensive business plans because the typical user doesn't really ever need to upload anything that strenuous. 

 

They don't want  users running businesses (websites) off of their "home" internet connections.

 

They want to sell them the more expensive "business" connection.

[ProjectBox153]

2 minutes ago, Cracktic said:

This is something that has confused me for a long time. Why are ISP upload speeds so much slower than download? The canned reason is often "Well users spend more time downloading than uploading so networks have been optimized for download speeds by design". This is a common theme with cable and dsl. Often times in contrast, I see that fiber connections are synchronous (i.e. giving the same upload speed as download speed) .

I also feel like this "optimized by design" explanation is a cover for laziness or something else like ISPs are somehow using that bandwidth that isn't allocated to user upload connections for something else. I really don't know how cable and dsl infrastructure works as far as what determines speed capabilities so I'm guessing. I also have to wonder why fiber connections aren't "optimized by design to provide faster download speeds" and instead give synchronous speeds.

If an ISP gives the option of a fast upload speed on a residential connection, users wouldn't need to pay for a specialized connection that would cost a lot more if they were running a server. ISP's really don't want people running high-traffic servers off of not-too-expensive connections. 

[NTDaws]

Our ISP has good speeds. http://www.telus.com/en/ab/internet/?INTCMP=LNK_frmCTA_TopNavigationAll_toHomeInternet

[pwn_intended]

You wont like the answer:

Residential ISP networks are designed for higher download speeds because, well, that is what the use case is for residential internet. Also, this has to do with how bandwidth on the cable is used as well. A much larger portion of the frequency range (for COPPER lines anyway) allotted for downstream traffic because that is what is needed by 99%+ of consumers.

 

Business internet lines will be optimized differently depending on your specific needs and what the ISP actually has to offer.

[Elerek]

A connection to an isp can only handle so much bandwidth. If you get 60 down and 10 up, you have a 70mb/s connection. Sure, they could give that to you as 35/35, but that's not how you use it. You would be wasting a huge amount of that bandwidth while you sit there waiting on youtube to load.

[tt2468]

8 hours ago, Dawson Wehage said:

Our ISP has good speeds. http://www.telus.com/en/ab/internet/?INTCMP=LNK_frmCTA_TopNavigationAll_toHomeInternet

Cool story bro!

[Curufinwe_wins]

7 hours ago, Elerek said:

A connection to an isp can only handle so much bandwidth. If you get 60 down and 10 up, you have a 70mb/s connection. Sure, they could give that to you as 35/35, but that's not how you use it. You would be wasting a huge amount of that bandwidth while you sit there waiting on youtube to load.

You say that like bandwidth is constantly consumed...

 

It isn't.

 

The ONLY reason they do it is because they can (aka profit). Because they can charge more for a higher upload speed in the right conditions.

[mariushm]

Sometimes it's a limitation of the medium.

For example, in the case of ADSL (internet through phone line) or cable internet (DOCSIS) by design the download bandwidth is much higher than upload, because in real life you're usually downloading more than you're uploading. For example, you request a web page, and you get the text, pictures, and everything.. so for 1 KB of request (upload) you may get 200 KB of data back.

By making things asynchronously (disproportionate), it's possible to raise the actual download bandwidth with such technologies.

 

That's no longer the case with optical fiber where the technology allows for same bandwidth in both directions.

The ISPs however still have to pay for bandwidth, for the interconnection to other networks.. the upload traffic users make is what costs the most for them, as most of the download content is usually free (comes into ISP networks through internet exchange points where ISPs exchange data at no cost or very little cost). 

[brwainer]

I don't know how things work for DSL, where you have a dedicated line per residence to the telco, but for DOCSIS you have you have a limited amount of bandwidth that is shared for an entire neighborhood, or possibly part of a neighborhood (in the city it might be per block or for a few blocks). Depending on the amplifiers and splitters, you have between 750 and 1000MHz to play with. But before you can talk about internet use, you first have to allocate a large portion of that bandwidth to TV channels. Each analog TV channel (NTSC) uses 6 MHz. Right before the advent of digital TV (QAM), it was common to have 60-80 channels available on cable. That's 360-480MHz already in use out of 750-1000, meaning about 1/3 to 3/5 of the bandwidth. Digital TV improved this greatly, now we can put 4 SD channels, 2 720p channels, or 1 1080p channel in that 6MHz spacing - this is why you may see channels with a period or dash in the middle, like 6.2 which means the second channel on the 6th frequency band. Most cable companies still offer SD channels for a large portion because it allows them to offer greater internet speeds, or conversely more channels without taking up as much bandwidth.

 

Up to this point we are only discussing physical limitations. It is basically impossible to use more than 1000MHz on coax unless you want amplifiers every 50 feet.

 

From here we start to talk about ways the cable company might be screwing you a bit. Of the remaining 400-700MHz on the coax, this must be split up between all the houses in a given "cable plant". A cable plant is all the houses and businesses that share a single headend. Every single communication in a cable plant is broadcast - your modem actually receives every bit of data that the other modems upload, and also every bit of data someone else is downloading (the communications are encrypted between the modem and the headend). This, more than anything else, is why your internet speeds slow down in the early evening. At the time of installing the cable plant, you have to decide how big or small it will be. Say there is a new neighborhood of 1000 houses being built - how many seperate cable plants do you install? 10, each with 100 houses? 4, each with 250? The cable company has to decide now, at the time the coax is being laid, because separating it in the future is very costly - more costly than separating it now, but they don't want to spend a lot of money now either. This is the first place the cable company can screw you. If they think the neighborhood is going to be a less wealthy one, they will put more houses per network than average. If they think it will be a very wealthy neighborhood, they will put less houses than average per network.

 

Also at the time you install the cable plant, you have to decide how the available bandwidth (after subtracting TV service) is to be divided between uploads and downloads. If you devote too much bandwidth to uploads, it will go unused. Devote too little and you end up causing congestion. I don't have any data to back this up, but my own experience of working for an ISP is that normally, upload traffic is 10-15% of downloads - and this is even if the bandwidth caps are removed (sometimes our system is a bit inconsistent about applying the upload cap). At some point, the cable companies all settled on around 35MHz for uploads for residential, and more for areas where more business use is expected. The reason this has to be decided when you install the cable plant, is that the amount of upload traffic has to be set in the amplifiers. The amplifiers don't just have to amplify traffic downstream, towards the users, but also have to amplify the upload traffic upstream, back towards the headend. If you don't set this properly, you will royally screw up your signals. So once a cable plant is installed, you have to reconfigure or replace every amplifier in the entire area to increase upload speeds.

 

Beyond this first few years when cable systems were a new thing, you enter a chicken and egg situation. Why are uploads a fraction of downloads? Because that's how the amplifiers are configured. Why are the amplifiers configured that way? Because upload traffic is a fraction of download traffic. It can be argued that upload traffic would be higher if the upload speeds were symmetrical, but on a DOCSIS system you would never be able to test that theory. But I've see the aggregate usage of 500-5000 residents in apartment complexes, that share fiber connections between 500 and 10,000 Mb/s, and I can tell you that if the upload cap is removed, upload traffic barely increases, and sits around 10-15% - and this is on all-ethernet networks, where each resident can theoretically get gigabit in each direction.

[Remix]

Many speculate that the primary cause for not having high upload speeds on a residential connection is the ISP not wanting you to host things from your home. While I would tend to agree this is a reason, I know it's not the only limitation. With DOCSIS 3.0, most ISPs have a fairly limited spectrum. Some are ~600MHz and some are 1.2 GHz. TV uses a decent chunk of that spectrum. The rest is left for DS and US, and considering most individuals download more than they upload, 4 US channels is technically enough for ~100 Mbps of upload. If the CMTS only has 4 US channels, that's a total of ~100 Mbps. Allocating users a high rate of that would slow others down. DOCSIS 3.1 fixes many of these issues, but because of the mixed environments and limited spectrum, we aren't seeing the Upstream Channels change... yet.

 

Fiber isn't limited in the same way, though it still has limits. The cable is able to withstand high-speed connections at symmetrical rates, unlike the way Cable or DSL was built. We see similar limitations in LTE, where uploads seem capped. This is due to spectrum too.