D/l acting weird
Posted 14 September 2005 - 10:54 PM
Posted 14 September 2005 - 11:16 PM
When you get an internet connection, whether it is Broadband (CAble/DSL) or NarrowBand (Analog Modem) you have a max amount of data you can transmit or receive at any given time. This is referred to as your BandWidth.
For an analog modem (dial-up), the max this bandwidth will be is 53K (that's kiloBITS not kiloBYTES), even if your modem is listed as 56K. This is a regulatory communications mandate by the FCC. Then to make matters worse, under ideal conditions, you'll probably only get 44K out of the phone companies lines.
This is the reason people are switching to broadband (Cable/DSL) most home users get ADSL which has download speeds of 1.544mbps(megaBITS per second) - 8mbps. and allows you to share with other telephone equipment.
Now, regardless of which one you have or choose. everytime you request information from the network, it eats up some of this bandwidth.
if you are downloading a file, that is using some of the bandwidth....if you then start browsing the internet...that's going to use more...start something else..still more gets used...etc..
the transfer speed and time remaining numbers in a download are estimates at best. once you stop all the other applications from using the bandwidth...there is a whiplash effect to the download estimates.....on a modem connection anyways.....it will jump sometimes as high as 11k then the numbers drop back down to around 4-5k once a more steady rate can be established....
Posted 15 September 2005 - 02:13 PM
This is a regulatory communications mandate by the FCC.
Just to add to what brianmil0923 said, the FCC cap on bandwidth for dialup connections is partly due to the fact that analog telephone lines were designed and put into use long before there was such a thing as a computer.
When the lines and equipment were developed, the engineers decided that the frequency bandwidth for a single voice channel would be 4,000 Hz. They then used PCM (Pulse Code Modulation) which measures the magnitude (size) of the wave 8,000 times every second. It's then turned into symbols, which in this case happen to be 8 binary digits (bits). This means that every second on a PSTN (Public Switched Telephone Network) line, 64,000 bits per second are being transmitted on one channel. Each line is made up of 24 channels: 23 are voice, and the 24th (D-channel) is a control channel.
Some of that 64,000 bits per second is used up as carrier signal and some is the guard band which prevents interference. This is what limits your telephone line to being able to transmit data on a dialup modem to approximately 53Kbps (Kilobits per second). Speeds lower than that are usually caused by the fact that wires and equipment aren't perfect, and we can never get perfect usage out of them.
As brianmil0923 said, the amount of data you can transmit in one second has to be shared among all the programs that are trying to transmit. The more programs you're using on the Internet, the less of the total each one is going to get. He's also right on that the download times/rates quoted by programs aren't always accurate, but you can use this bandwidth tester to find out what your exact speed is.
Posted 17 September 2005 - 06:27 PM
Its good to see another true blue TECHY in here
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