Why Uploading Is Slower Than Downloading

If you're like most of the rest of us, the speed at which you upload is way slower than the speed at which you download. That makes sense if you think of the Internet as a publishing medium, with most of its participants as recipients. It makes much less sense if you think of the Internet as a participatory medium.

So, I canvassed some friends and colleagues who know a lot about this stuff — I'm leaving them unnamed so my mistakes won't besmirch them — about whether this asymmetry is baked into the technology or whether it's a matter of choice and policy. The answer turns out to be complex. But the bottom line is that we download faster than we upload because of economics, not physics. The economics are those of telephone and cable companies. Their business models assumed the value of the Net came from the content they deliver to us. The business models got written into a physical infrastructure that favors downloads over uploads. So, here we are.

It could have been otherwise. If only the access providers hadn't built a business and an infrastructure on the assumption that we really just want to lean back, relax, and scarf down gigabits of tasty content.

Physics of course sets the boundaries for any business model. If you're uploading and downloading through the same "pipe," increasing upload speeds requires decreasing download speeds. To oversimplify incredibly complex technology, it's like having a single tunnel for one-way traffic: If you now make it two-way (instead of, say, putting in another tunnel), you've reduced the one-way capacity. When the Internet started almost all of us downloaded far more than we uploaded — simply visiting a Web page requires downloading it. Asymmetry reflected our typical usage pattern. Most of us still pull down more than we put up, but with the rise of P2P networks, voice over IP, etc., we're doing much more uploading than we used to. And if the access providers made static IP addresses more affordable, we could host our own Web sites and be uploaders to everyone who visits.

Nevertheless, users generally aren't picking up their pitchforks and demanding higher upload speeds ... perhaps because when we can't upload very quickly, there's little market for services that require a lot of uploading, so people don't build upload-heavy services, so we don't see good reasons to demand faster uploading...

The answer to the question of asymmetry gets more complicated when you look at the various ways of connecting. (There are some details in the longer version of this post.) For example, asymmetry seems to have been engineered into the way the providers deployed coaxial cable, but would be easier to turn on with optical fiber.

Nevertheless, given that physics requires an apportioning of bandwidth between up and down, economics could route around physics: If a provider were committed to providing symmetry without lowering download speeds, it could have (for example) put in a second line when it put in the first. The trade-offs were made by the access providers, largely based on business concerns. For example, one reason we have asymmetric fiber may be that the providers have been charging such high premiums for symmetric access that they don't want to lose that extra money, even as the technology makes symmetry more do-able.

So, as was said by David Isenberg (who gave me permission to credit him): "Asymmetry is a belief system. The purveyors of connections looked at the Internet and saw TV, then acted according to what they saw." That's the infrastructure they built. That's the infrastructure we're currently stuck with. If we can get unstuck, we might at long last get ourselves some symmetry...or have broad enough broadband that symmetry doesn't even matter.

 

 

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Comments

[RTIII]

"Physics of course sets the boundaries for any business model. If you're uploading and downloading through the same "pipe," increasing upload speeds requires decreasing download speeds."

This sentence and ones like in the article are patently false.

I agree with a number of points made in the article, but the questions of physics should have been passed by someone who actually knows something about physics.

...Messages can be sent bidirectionally (in virtually every current physical technology in use on the internet today) at speeds that are completely independent of one another. A good analogy is that two people in one room can both talk at the same time and create words at different rates; their different vocal signatures (frequencies, harmonics) permit our ears (brains) to distinguish them.

Just because it _can_ does not mean that businesses (hardware vendors who make the underlying physical apparatus and ISPs who use that hardware) actually take advantage of the possible physics. My point is that "Bandwidth" is not necessarily shared between both directions of a bidirectional link, and in fact sharing like this is somewhat rare with cell phone / PDA links being the only one that immediately comes to mind because all users share a common set of frequencies. Yet even then, you can get better bandwidth by having multiple radios and linking them together - still sharing the same underlying medium, though!
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[unitron]

The one-way versus two-way tunnel analogy explains it pretty well it you take it far enough.

As long as most of the demand for use of the tunnel is in one direction it's a trade off between who goes which direction how fast and who wants to fork over the extra money to build that extra tunnel.

Until every household had a need to put as much stuff on the Internet every day as, oh, say, HuffingtonPost, it makes more financial sense not to spend the extra money on a second tunnel.

Remember, when you're downloading, HuffPo is uploading, and the bill from their ISP is probably a whole lot bigger than the one from yours.

[Jeff Yablon]

Oh please. This is TOTALLY about Economics

Want Proof? Think of a little thing called a T-1. Companies STILL buy them. Symmetrical upload/download speed at guaranteed rate, to your telecommunications provider's Central Office.

Differing up/down speeds with the better being down is a consumer-grade-originated service that was designed A) assuming that surfing (receiving) was what consumers did, and B) making it harder to run a business over those lines (you can't have YOUR sever sending OUT data slowly).

So the economic reality is that there's no reason to make that better now, because it's both what we've come to expect and protects existing so-called (but not really) "better" lines.

Jeff Yablon
President & CEO
http://answerguy.com

[jeremydbrooks]

Exactly. Not sure if they still do, but in the past I've used DSL, cable, and even dial-up ISPs who blocked outbound traffic on standard web, mail server, DNS, and FTP ports--the only possible intention being to prevent consumers-level accounts from running servers. The goal there obviously was to sell you a business account and/or sell you on their webhosting services and make sure that when you gave out your business card, the email addy was selfimportantisp.netntisp.net.

[Lochmon]

This is a problem that should mostly take care of itself in the next few years. People are uploading more photos, videos and other large files than ever before. "Cloud computing" needs more symmetry in upload speeds. Google Wave and similar techs, the same. Simply changing the balance in what people are trying to do will force changes in the infrastructure, because the new efficiencies will become the more economical way to do business.

The real problem is not the upload/download rate disparity, but that we pay far more money for far less bandwidth than nearly any other technological-developed country. Everyone concerned about this situation should be paying close attention to the FCC right now... they're in the process of rewriting the rules of how broadband is provided in the US.

[dkoch]

the facts on the physics are that the current technology in cable modems that are being provided by ISPs today are capable of hundreds of megabits per second, up and down, yet ISPs are only motivated to increase bandwidth availability when the competition does so also..., so, yes, the reason is economics, but it's based on a policy of only giving up the bandwidth that is required to compete in the market place, versus offering up the available technology for maximum available bandwidth speeds.

[SeanOcali]

Why would a telco want you, the customer, competing with them? When you have the bandwidth to host your own server, why do you need pay for expensive hosting?

[SusanStoHelit]

Fact is, this is the correct decision. We do need to download a lot more, and significantly larger chunks of data, than we need to upload. You upload emails, some pictures, videos once in awhile. You view far more pictures than you upload, and ridiculously more video than you upload.

Download needs to be faster. Pretty obvious - just look at these little forums here. I'll read 100 posts (at the least) for every post I write and upload.

This is a correct business decision, and a correct decision for all of us.

[macweenie]

I am SO there!

I am currently running (though I will disavow this statement due to my EULA with my provider) a website from my own Mac (testing mode only at present) and my current problem is how do I upload large files to end users either via FTP or DAV FASTER? I need to move hundreds of files per job which often works out to 1 gb of material plus or minus and just moving those files takes MUCH LONGER than processing them into a final product! I am willing to pay a fair price for symmetrical access but there's what the providers deem fair and what the market says is fair.

Unfortunately those of us who care about symmetry comprise a fairly small market. I sense severe rectal pain in my future.

[kendraro]

These are the kinds of things we discuss around my techie household frequently (just the other day in fact) we kind of think that when people Really start to use the internet there is going to be massive overload. Because there is so much unrealized potential right now - and I am really sure that it has been a mistake to let the decisions be made solely by those with a profit to make. I know it is the sacred American Way, but I think having someone look out for what actually serves the needs of the people is a good idea long overdue.

[billkarwin]

The truth is that SDSL (sometimes called "business DSL") with high-speed upstream bandwidth and static IP addresses has been available for as long as ADSL.

SDSL isn't advertised as much as ADSL because there's less consumer demand for it. If telecom companies have built more ADSL infrastructure, it's more likely because of market demand than because they have some kind of agenda.

SDSL is also typically more expensive than ADSL. That's no doubt partly because of the economy of scale, but also because if you prefix any product with "business-class" or "enterprise" you can immediately charge three times as much for it.

With respect to running your own web server, it's far less expense and work to use an inexpensive hosting service. If you still really want to run a web server from an ADSL or SDSL connection to your home, have you looked at dyndns.com or similar services? This is a solved problem.

I think you're seeing problems where there are none.

[userw014]

I'm a DYNDNS user. Nice way to make my personal website (which I use for bookmarks) available at any browser I might use. I also run a vpn off of it - to access my own IMAP mail server - I want my personal e-mail that I want to keep on physical hardware I own - not subject to bankruptcies or changes in business models.

As for VOIP - I'd rather stick with regulated POTS (Plain Old Telephone Service.) I've hard far more service trouble with Comcast (my ISP) than my telco.

[ramblingjohnny]

I use xmarks to sync my bookmarks between browsers that remove a lot of pain when I have to nuke a partition like I did last night.