Mar 19, 2014

Why are upload speeds so much slower than download speeds?

Whenever I have ran a speedtest on a home network, download speeds are always much faster than upload speeds, sometimes 10x as fast. I’m just curious, if they are using the same “pipe” why wouldn’t they be the same?

How are upload and download speeds related, and why are they different?

"You download much more than you upload.

A typical web browsing session might involve several small requests sent from your computer to remote sites requesting pages (anything sent from your computer to the internet is an "upload", including requests to fetch pages), but the size of the pages and what they contain typically dwarfs the size of the original request by factors of 100 or even 1000 or more at times. A tiny 200 byte request for a YouTube video being uploaded could result in a download of many millions of bytes.

It won't matter to you that the upload of that tiny request is somewhat slower as long as that huge download is as fast as it can possibly be.

The designers of the various technologies that we use to connect to the internet have realized this, and use it to "shift the balance" in your connection. Whereas in the past you might have seen 50/50 allocation in your bandwidth - half for uploading and half for downloading - the technologies being implemented in many cases effectively take away some of the uploading capacity in order to make the downloading speeds faster. Perhaps an 80/20 allocation of the available capacity instead: downloads are faster because you do them more, uploads are slower but you're likely not to notice or care."

I’m not entirely certain, but I think it is related to two things, (1) the average user takes up much more bandwidth downloading music, video, kitty photos, etc. than they do uploading anything, and (2) to discourage file sharing/bittorrents. I’m not sure how hard it is to shift the “balance” (percentage of bandwidth used for uploading vs. downloading) based on need at the moment. Perhaps someone who knows a little more about this topic could expand on it

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