Oliver Lineham wrote: > At 12:56 12/09/00 -0500, you wrote: > >> Part of the idea that cable modems will get slower with more and more >> people in the 'hood using them is true, part isn't. > > Wow, dan, that was a great explanation of things - thanks! you're welcome, I'm glad so many enjoyed it.. when i get some time, i'll edit, format, and post it on the evolt website.. > > One remaining question I have is, how do upstream speeds compare? I > know the cable modem speed is set by the cable company - eg you might > only get 512kbps upstream although the modem is capable of 2mbps. > Obviously both DSL and Cable have more capacity downstream than > upstream, but which is better in that respect? Good question. Lets take a look at DSL uploads first. DSL is a generic term that encompasses a variety of technologies. Each of these technologies is somewhat the same, but also different in how it can compress data. Compressing the data to send over you're phone line allows you to have faster speeds.. The better the compression, the faster uploads you'll have. The difference between an analog modem(at 56K or 33.6K or 28.8K like many have) and a DSL modem isn't much, but at the same time alot. Don't know when I became the DSL expert here ;) anyways.. An analog modem is so 'slow' because it only uses a small portion of the available amount of information that could be transmitted over copper wires(your phone line), the maximum amount of data that you can receive using ordinary modems is about 56 K(the fastest modem currently). The amount you can download is limited by the fact that the telephone co. filters information that arrives as digital data, puts it into analog form for your telephone line, and requires your modem to change it back into digital. Basically, its dumb and ineffcient. The reasons DSL is so fast over the same wires as an analog modem is digital data(DSL) doesn't need to be changed into analog form and back, like an analog modem does. Data is transmitted to you from the phone company in pure digital form, letting them use more of the 'pipe' that your phone lines offer. Christ, i'm getting of on a tangent here again so I'll cut to the chase :) Here are some of the 'flavors'(different compression techniques) of DSL: ADSL: Asymmetric Digital Subscriber Line - the most common form of DSL. Allows for good download speeds, but upload speeds are limited because most is devoted to the downstream direction. For the majority of web users, this is great, because they don't spend a lot of time uploading data. Typically you'll see 1.5Mbps at 18,000 feet; 2Mbps at 16,000 feet; 6Mpbs at 12,000 feet; 8.5Mbps at 9,000 feet from the phone company download speeds. You'll see from anywhere between 16 and 640Kps upload speeds, depending on distance from the phone company(and therefore signal degridation) HDSL: High Bit-Rate Digital Subscriber Line - oldest form of DSL. It allows for equal upload and download speeds, although it sacrificies(i'm not a f-ing spelling bee contestant obviously :) overall speed to achieve equal upload and downloads. SDSL : Symmetric Digital Subscriber Line - almost the same as HDSL but much faster. Can carry a full t-1 speed(1.54Mps) in full duplex(both upstream(upload) and downstream(download)). You have to be pretty damn close to the telephone company(or one of their switches) to get this though, because the signal degrades in a hurry. VDSL: Very HighDateRate Digital Subscriber Line - if you're within spitting distance of you're phone company, this is the fastest option you can have. You can typically get 55Mps with VDSL's compression algorithms. The tradeoff is that you have to be within 800 feet(i dont know how many meters that is :) of the phone company. There are a number of other compression algorithms out there that add to the alphabet soup, but those above are the most common. And as my previous post mentioned, this is between you and the phone company, *not* between you and the internet. So to answer you're question onlineham ;) - your upload speed depends on what compression technique you're using, which is directly correlated to how close you are to the phone company. You *can* get as high as 55Mps. The common user however is somewhere between 128Kps and 540Kps for upload speeds. A typical cable modem user(myself with time warner) can achiever much higher or lower as well. I can upload to my servers at work at about 1.2Mps in an off-peak time. Naturally, congestion can lower that(or a DSL line) down to what I used to use for a modem when I had an Apple ][gs :) (my favorite computer of all time still btw) Hope that answered your question and cleared up some of the confusion about DSL. Guess I'll have to put this into my other post and make an article out of it :) Thats cool though, we all know that people who put their good posts from thelist( http://evolt.org/index.cfm?menu=8&cid=3093&catid=18 ) on the evolt website are bound to become cult icons of sexy geekiry like our own sgd :) .djc.