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We have a fiber connection from CenturyLink--one of their first. Our download speed is 10 Mbps, but upload is usually less than 1 Mbps. My understanding is that fiber is fundamentally different than DSL, in that reducing upload speed doesn't allow for more download speed. Is there any technical reason why they would set that limit?

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In all cases the download speed is higher because the upload speed is only needed for uploading a lot aka "servers". When download a file the OS generates ACK (acknowledements) "yes" the packet is ok or "NACK" no it is not. These ACK are 4 bytes or less in size so you download 1500 bytes and send back 4 bytes or less. For people who mostly download slower uploads speeds are a non-issue. – cybernard Apr 24 '13 at 1:29

I asked this same question about my internet, which is 115Mbps down, 1.5 up. The response I received basically stated that they want to encourage people to buy a business internet plan if they are doing a lot of uploading.

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The only reason is economics, in general people don't need that much upload speed so it's something the average customer won't really miss. Therefore, it discourages people with these needs to take the cheaper plans and forces them to get a more expensive/business plan which has more upload.

There is a 2nd reason which is also economic in nature, ISP's have contracts about how much bandwidth they use and usually they don't expect much upstream bandwidth (one of the major reasons that many ISP's throttle Bittorrent traffic).

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