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i'm from Malaysia. I am subscribed to 2mbps pack from my country's ISP. But all i get is only 200kbps when download files from the internet, when i test my speed on speedtest.com , it shows me 1.7mbps.

I am pretty confused , ISP should give users what they stated , yeah a 2mbps. But i only recieved 200kbps and the speedtest shows 1.7mbps which makes me confused even further.

So i started googling and found out that it is related to something called VPN compression?

can anyone explain to me how these things works? why am i getting much much lower speed than i have subscribe to. (I am using a D-Link DSL-2750 U modem)

Thanks.

ETAN
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7 Answers7

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Mb/s means megabits per second. To convert to megabytes (MB), you simply divide by 8, since there are 8 bits in a byte:

2Mb/s = 2Mb/s * 1Mb/8MB = 0.25MB/s = 250 kB/s

So you can theoretically cap out at just under 250 kilobytes per second.

Note that I have used megabyte here, which assumes 1000 kilobytes per megabyte. The convention for unit steps of 1024 is used for mebibyte (MiB), which consists of 1024 kibibytes (kiB). What your browser/download tool uses depends on how the developers implemented the math, but in the case they do use mebibytes/kibibytes, your theoretical maximum speed would simply be:

2Mb/s = 2Mb/s * 1Mb/8MiB = 0.25MiB/s -> 0.25MiB/s * 1024 kiB/MiB = 256 kiB/s

Note that kilobyte is a common misnomer for kibibyte, but the difference is neglegible for most purposes (as you can see above, both results are fairly close to eachother). If you require an exact calculation, and you're unclear what units the result is in, you need to ask the developers how the math was implemented in the program or operating system.

Breakthrough
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Actually the internet service providers mentioning our internet speed in bits per second.

And your speedtest website also showed it to you in bits per second ,whatch it clearly.

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But in our computer level,our download managers or some applications shows the download speed in Bytes per second like this,

enter image description here

8 bits = 1 Byte

So if your ISP mentions 512 Kbps , 1 Mbps , 2 Mbps , 4 Mbps ., to calculate your download speed in Bytes simply divide it by 8 , that will be your download speed in KiloBytes or MegaBytes . example

512 Kbps = 64 KB/s

1 Mbps = 1024 Kbps = 128 KB/s

2 Mbps = 2048 Kbps = 256 KB/s

4 Mbps = 4096 Kbps = 512 KB/s

Desingh
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Your speedtest shows 1.7Mbps, your connection is 2mbps, your download speed is approx 200kBps.

Nothing is wrong

b=bits

B=Bytes

Akash
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Line speeds are measured in decimal units and in bits per second. Data transfer rates are measured in binary units and bytes per second. Also, the line doesn't just carry data, it has to carry address and control information as well. The overhead of the line encoding is already figured in, but the overhead of control and address information is not.

So if you have a "2Mbps DSL" service, that means your line carries 2,000,000 bits per second. You divide by 8 to get bytes per second, or 250,000. You can then divide by 1,024 to get kilobytes per second, or 244KB/s. TCP over DSL has a maximum efficiency of about 95%, so multiply by 0.95 to get 232KB/s. So a 2Mbps DSL line would be expected to provide a maximum download speed of 232KB/s.

So you're in the ballpark.

By the way, speed testing sites generally just measure the usable data rate over TCP and then multiply by eight. So a 2Mbps DSL line, even if it was actually providing precisely that line rate, would actually give a lower measurement (around 1.85Mbps).

David Schwartz
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People tend to forget to read the fine print. Most ISP don't say 2mbps, 20mbps, 200mbps. Or they do say it, but then in the fine print there's this:

They say UP-TO 2mbps. Unless they made any guarantee it could very well be only 0.5mbps and you're SOL then.

Grumpy ol' Bear
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For various reasons, actual "speedtest" results are generally about 20% lower than provisioned speeds. This is just the way it goes. So with a 2mbps service, I would expect speedtest to show 1.8mbps. If I had 1.7mbps I would not complain.

The 200kbps is possibly due to restrictions on the server you are downloading from (most servers have outbound bandwidth restrictions to avoid being clobbered by DOS attacks) and possibly a problem with your TCP windowing. Since you are getting 1.7mbps from speediest, it is not likely to be a problem with your ISP.

More likely is that you have confused bps with Bps, as 200kBps = 1.6mbps

Old Pro
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Another possibility: your provider promised you DSL up to 2000 M where the dsl and 2000 M are in 36 font and the up to is in 2.5 font. You must share the bandwidth with people on the same physical wire. This is similar to UMTS where you share the bandwidth with others on the same cell.

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