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I know this isn't a network website but I had to think of a fast way to ask this question where knowledgeable people exist.

I have 12 MBps down, 2 MBps up, I have a home server that when I download from it externally I max at 256 KBps.

Anyone know why?

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migrated from Mar 22 '11 at 0:15

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Unless you're actually getting that kind of throughput, you might want to change the capitalization on the speed measurement (MBps reads as Megabytes, whereas Mbps reads as Megabits). – happy_soil Mar 22 '11 at 1:41
up vote 6 down vote accepted

Your bandwidth is really 2Mbps (bits per second... that is 256 kilobytes per second)

2 * 1024 / 8 = 265
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It's sneaky how ISPs measure bandwidth, but this is right on. – Toast Mar 21 '11 at 21:35
it's not sneaky, it's how it has always been done. – Alnitak Mar 21 '11 at 21:38
It's not really sneaky as all. It's just how we look at numbers. If you really want to be confused look how hard drive size is measured. When they write the number on the box the use the 1000 based values but when you look at the disk size in your file manager it's typically based on the 1024 based value. – Matthew Whited Mar 21 '11 at 21:38
@Toast: Networking always (in my experience, at least) uses bits, so I wouldn't say it's really sneaky. It's not like hard drives, where everyone except drive manufacturers measures storage capacity in base 2. – CodeninjaTim Mar 21 '11 at 21:40
I say it's sneaky, because most people don't realize the difference. I called my isp's tech support to explain it to me, and they told me all the speeds were in bytes. When I tried to clarify, they didn't know what I was talking about. – Toast Mar 21 '11 at 21:49

Bandwidths are always measured in bits per second, and your home connection will be measured like that too, i.e. 2 Mbps (note - small 'b').

File download displays however tend to show in bytes per second, since you really care about the number of bytes you're downloading, not the number of bits :)

So your 256 Kilo bytes per second of download speed is approximately equal to 2 Mega bits per second of bandwidth.

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that's very unlikely. 12 MBps is roughly 100 Mega bits per second, i.e. ethernet speeds. – Alnitak Mar 23 '11 at 19:24

You're bandwidth, as an end user, is always bias towards download speed. You have a maximum bandwidth allotted for both up and down, and most users don't care if they have high upload speed.

edit, are you sure it isn't Kb/s? look at the capitalization of the B

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Those are advertised and theoretical speeds. Just like "100Mbps" ethernet doesn't give you 100MBps actual transfer rates, the telcos and cablecos use weasle words such as "up to" or "as much as". The hardware and line may be capable of sustaining a 2Mbps connection outgoing from your home, but that doesn't factor in things such as TCP overhead, throttling, network congestion, etc...

256 v.s. 2000 is a bit extreme, but I'd suggest checking if your ISP is throttling per-connection speeds - try two uploads at the same time. If the effective speed on both drops to 128, then you've really only got a 256kbit link. If both sustain 256kbit, then you're being throttled on a per-connection basis.

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