Bandwidth? What's that in web terms?

[reith]

Ok, I'm not exactly the most receptive internetter but I keep hearing references to "bandwidth" in web-speak, like: that uses too much bandwidth; you're only allowed so much bandwidth per month; we need more bandwidth to transmit that etc.....

...none of which makes sense to me. I once engaged in electronics with a bit of radio and understood bandwidth to be the size of the band (in Hz/khz/Mhz) that a transmission uses to contain its sidebands. Like UK FM stereo radio uses a bandwidth of 38khz per channel, referring to the carrier plus sum and difference of the maximum modulating frequency.

Google has a few explanations in these terms but not about web bandwidth. I assume when a transmission occurs it involves modulation on a radio carrier but wouldn't the bandwidth be fixed according to some standard?

Thanks for any descriptive explanation (though a technical site might help).

[Thorolf]

Very easy. The old term has been translated to the modern web life, because the problems are rather similar: In the old days, different broadcasters needed this common, limited good called bandwidth, which they were alotted, so that they could transmit their content. Nowadays, the internet bottleneck is always the size and speed of transmissions. Which is why you have to pay for more if you use more.

The word the Internet Service Providers use for size of transmission and/or speed of transmission is simply bandwidth, even if it has nothing to do with the old radio wave thingy.



Regards

[reith]

Ok, I'm getting there. Thanks. One more question if I may, then. I've heard said about downloading files... save them to one's hard drive rather than just open them as that takes up more bandwidth. Surely the same file transmitted over the same medium would occupy the same bandwidth? Or is that the "providers" are getting confused?

thanks.

[Thorolf]

No, it’s the same data. The point about taking more bandwidth, is that when you stream anything “live”, the server is busy connecting for the real-time playing time, but if you just download to your HD, the transmission is “over with” ASAP, which leaves the server free to pack and send data packets as optimised as it can, as opposed to the trickleing of real-time connection.



Regards

[Ron Ofir]

That, and when you save the file you can keep for future uses, however, if you open the file, you'll need to download it every time you want to use, thus using more bandwidth (note this isn't very accurate because of caching).

[reith]

Originally Posted by Ron Ofir

That, and when you save the file you can keep for future uses, however, if you open the file, you'll need to download it every time you want to use, thus using more bandwidth (note this isn't very accurate because of caching).

Ok, thanks. I suppose I resolve it in mind as "it takes more (time) of the same bandwidth". So web transmission pricing must be such-and-such actual bandwidth per unit time. Except the implications here are that the actual bandwidth can be varied according to the bitrate being delivered.

Almost a power equation like killerwatt/hours.

[Thorolf]

Home internet bandwidth in Norway is all about speed, (almost) none about GBs transferred…

Most home solutions here are free download/free upload, limited to a certain speed. Myself got 3896 kbps down and 454.1 kbps up at the moment…

You can test your own speeds here.

Regards

[chckn8r]

Originally Posted by reith

Ok, thanks. I suppose I resolve it in mind as "it takes more (time) of the same bandwidth". So web transmission pricing must be such-and-such actual bandwidth per unit time. Except the implications here are that the actual bandwidth can be varied according to the bitrate being delivered.

Almost a power equation like killerwatt/hours.

Think of bandwidth(or data transfer rate) as a size (width) of pipe. The more bandwidth you have, the bigger the "pipe" - giving you the ability to transfer more bits at one time.

An analogy: It's like filling a swimming pool with a either a garden hose or a fire hose. If you have the same amount of water in a reservoir, you'll be able to fill up the pool quicker with the bigger hose.

So a transfer rate of 5Mbps (Megabits per second) will get you a big file much faster than one with 500Kbps (Kilobits per second) - theoretically, 10 times as fast.

The other thing you were mentioning is "bandwidth per month" - it's not really the same thing as above, but rather what you were alluding to with respect to monitoring your electrical usage (how many killowatt hours you've used). Here, they're referring to how much data you have downloaded and/or uploaded using your connection in a month.

[reith]

Originally Posted by chckn8r

Think of bandwidth(or data transfer rate) as a size (width) of pipe. The more bandwidth you have, the bigger the "pipe" - giving you the ability to transfer more bits at one time.

An analogy: It's like filling a swimming pool with a either a garden hose or a fire hose. If you have the same amount of water in a reservoir, you'll be able to fill up the pool quicker with the bigger hose.

So a transfer rate of 5Mbps (Megabits per second) will get you a big file much faster than one with 500Kbps (Kilobits per second) - theoretically, 10 times as fast.

The other thing you were mentioning is "bandwidth per month" - it's not really the same thing as above, but rather what you were alluding to with respect to monitoring your electrical usage (how many killowatt hours you've used). Here, they're referring to how much data you have downloaded and/or uploaded using your connection in a month.

Thanks. I'm pretty ok with bandwidth in terms of baseband and modulated transmission. It was the seeming misunderstanding (as I saw it but maybe I was wrong) where, for example, the owner of a server would say "when you download click 'save' rather than 'open' because opening the file takes more bandwidth. I couldn't understand why a digital signal that gets reconstructed on my computer would take more bandwidth (i.e. uses a wider frequency band) whether it was opened or saved. I understand that one might take more time than the other but that doesn't affect the signal bandwidth as far as I can see, assuming the reconstitution would be identical in either case. It may be more about switching arrangement.
Also, people talk of cost relating to bandwidth according to how much up/downloading is done from a site. Fine, the line/transmission may be more or less busier but I couldn't see how that affected the bandwidth of the medium. I conclude that people are using the term a bit loosely.

The line I'm using right now is advertised as an 8Mb service. I tested it using Thorolf's link (thanks for that, Thorolf). The download came to 3Mb, the upload 400kb. So I surmise that the line is capable of carrying 8Mb/sec but 'pauses' and the switching system reduce the actual transmission rate.

oh well...back to the cocoa tins and string!

[MaestroX]

The line I'm using right now is advertised as an 8Mb service. I tested it using Thorolf's link (thanks for that, Thorolf). The download came to 3Mb, the upload 400kb. So I surmise that the line is capable of carrying 8Mb/sec but 'pauses' and the switching system reduce the actual transmission rate.

Unfortunately this is the scam of UK ISPs. They are allowed to advertise (and charge you for) "up to" 8Mb/s even if you never reach anywhere near that. The same goes for their ridiculous "fair usage policies" which are hardly fair to the customers.