Amar KHELIFI wrote: > > sorry i don't agree. > check the bandwidth calculator on the net, u will see that i > was correct. > + for the K and k and B and b, it is so obvious that an > explanation is not > necessary........... > thanx for letting my messages show up normally and then respond > to > them............;
I don't know what bandwidth calculator you're talking about but I suspect it measures throughput based on bytes. That's fine (and is, in fact, exactly the source of confusion I was talking about). Computers deal in bytes and so they're interested in how many bytes per second they can download. But a WAN circuit, which has nothing to do with computers, doesn't care about bytes. It lives in a bit world. A 32kbps circuit operates at 32,000 bits per second. With a good many years designing, building, and troubleshooting WANs under my belt, I can say this with some authority. I've directly observed thousands of WAN circuits with WAN analyzers. I know what rates they operate at. But don't take my word for it. Study the Digital Plesiochronous Hierarchy for yourself. You will find that the basic WAN unit is a DS0, which operates at 64kbps. That's 64,0000 bps. In North America, the next step up is the DS1. It consists of 24 DS0s multiplexed together plus 8 kbps overhead. Multiply 24 by 64,000 and add 8,000. You get 1,544,000 bps. Ever heard of that data rate? If not, you may be more familiar with the European system -- which also starts with a basic unit of 64,000 bps. Regardless of which hierarchy you look at, you'll find that the math doesn't add up according to your calculations. For example, 24 multiplied by 64 multiplied by 1024 plus 8kbps overhead would add up to 1,580,864bps. Most certainly not a DS1. > > > ""s vermill"" a icrit dans le message > de news: > [EMAIL PROTECTED] > > I should also have mentioned that the "B" is typically > capitalized along > > side the "K" when dealing with kilobytes (KB) and the "b" is > typically not > > capitalized when dealing with kilobits (kbps). That's > probably at least, > if > > not more, significant than the "K/k" capitalization (if, in > fact, any of > it > > is significant). I mention it because it seems to cause so > much > confusion. > > You won't see it around here much, but at some other forums > one of the > chief > > complaints relates to achieving only 1/8th the expected > download rate. > > What's happening, of course, is that the download is being > measured in > > KB/sec while the connection is rated in kbits/sec. I'll shut > up now... > > > > > > s vermill wrote: > > > > > > Amar KHELIFI wrote: > > > > > > > > since > > > > 1byte=8bits > > > > and > > > > 1Kbits=1024bits > > > > then > > > > 32kbps=32768bps=4096bytes > > > > there is no formula. > > > > > > Amar KHELIFI, > > > > > > 1kbits does not = 1024bits and 32kbps does not = 32768bps. > > > 1kbps = 1,000bps & 32kbps = 32000bps. "k" simply means > 1,000. > > > The whole idea of 1KB (KiloByte) = 1024 bits has to do with > > > binary math and the fact that computers deal in bytes vs. > > > bits. 2^10 = 1024, which is divisibly by 8 (whereas 1,000 > > > would not be). It would be very inconvenient for a > computer to > > > have to deal with information blocks that are not divisible > by > > > 8. Modern communications systems are not byte-aligned at > all > > > and deal strictly in bits. For example, a DS0 is 64kbps. > > > That's 64,000bps. > > > > > > As a side note, and I'm not sure that there's any official > > > convention to go along with this, in general, a KiloByte is > > > abbreviated KB, with a capital K. kilobits per second is > > > generally abbreviated kbps, with a lower-case k. Thus, when > > > you see a capital K, it's safe to assume 1024 is being > implied, > > > whereas when you see a lower-case k, it's safe to assume > 1,000 > > > is being implied. > > > > > > Regards, > > > > > > Scott > > > > > > > > > > > > > > > > > ""Robert Perez"" a icrit dans le > > > > message de > > > > news: [EMAIL PROTECTED] > > > > > Anyone know how the conversion techniques for converting > > > > bits, bytes, > > > > > kilobits, etc, to calculate bandwidth usages? > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=65186&t=65008 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
