<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by aborg</i>
<br />Can someone explain to me in toddler language plz
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Does this mean people have been abusing the open proxies on sucktech and thereby reducng available bandwidth that sucktech is blaming on poor MW customers being abusive.
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Let me try to give a simple explanation of the problem for the less tech literate.
The situation in South Africa is that local bandwidth is plentiful and relatively cheap. However, international bandwidth is insanely expensive due to Telkom's de facto monopoly on international data communications. Retail international bandwidth costs about R5000 pm for a 64 kilobits per second slot on SAFE-SAT3.
If you're an ISP you want to buy as little international bandwidth as possible because it will make up the bulk of your operating expenses.
Let’s say you are an ISP with 1000 users. Each night your users get home from work and fire up Google to find something or catch up on the latest news. The Google front page is pretty small size-wise ... it’s about 11 kilobytes. Now of that 11 kilobytes, 9 kilobytes is the Google logo image: "logo.gif". That means that about 90% of what you need to download to see Google's home page is this one image. You can search for lots of things and get lots of results on Google that change the text you are seeing on the page but the Google logo stays constant and unchanging.
Now there are two ways to give our 1000 users the Google logo image. Allow all 1000 users to download it individually which would require about 1000 X 9 kilobytes or 8 megabytes of international bandwidth. OR, we can download it once, as the ISP, and then "cache" (save) it locally on our system and give it to the other 999 users using cheap local bandwidth. If we do this we have saved nearly 8 megabytes of international bandwidth! A HUGE saving!
The type of software that does this local caching is known as a proxy. Squid is a well known example of such software. But there is a problem. If we cache stuff locally as the ISP our users might not be getting the latest split-second-up-to-date-version of international sites. Devious, tech literate, users of our ISP want to be sure that what they are seeing is the very latest up-to-date version of international sites when pressing "refresh" in their browser. So they choose not to use our proxy and set their browsers to connect directly to our international pipeline. This is a problem because our 1000-1 = 999X bandwidth saving is now only a 1000-2 = 998X bandwidth saving. And so on …
So to FORCE all our users to first try to get content they request from our proxy server rather than use our expensive international pipeline we use a "transparent" proxy. The "transparency" means that our users are forced to go through the proxy whether they want to or not. It's not optional, that’s why it’s "transparent" to the user.
For example some time back MWEB only had a 40 megabyte international pipeline that served about 100000 users. Caching content with a proxy makes using a pipeline as small as 40 megabytes a feasible option rather than needing a 100000 X 56 kilobits (analogue modem) = 680 megabyte pipeline. MWEB only needed an international pipeline 5% the size of what they otherwise may have needed. (I’m ignoring the contention issue for now … lets keep this simple!)
Now there is another concept to understand: Open vs. closed proxy's.
We don’t want any Joe Soap to be able to connect to our proxy and request and receive content. Our proxy is the "gatekeeper" of our expensive international pipeline. Once a content request is accepted, and the content is not found locally, it has to be downloaded via our expensive international pipeline. Naturally we should only allow our OWN users (i.e. the 1000 legitimate customers of our ISP) to be able to use our proxy. This is a closed proxy.
On the other hand if we configure our proxy as an open proxy, which is normally the default setting, any Tom, Dick or Harry can connect to it and download content using our international pipeline without paying a cent. If this happens who suffers? Our 1000 legitimate users suffer lower speeds and we as the ISP bitch and moan about our users "using too much bandwidth". We as the ISP would typically say things like "6% of our users are using 50% of our bandwidth". Sound familiar???
Do you know of any group of people in ZA who have lots of local bandwidth but have no international bandwidth??? Come on think! ... YES .... Capped ADSL users. I hope the penny is dropping by now??
Naturally open proxy's can be used and abused by anyone who knows about them not just local capped ADSL users. As it happens open proxy’s are regarded as being so valuable by hackers and other nefarious types that these people use automated software packages to search for such open proxy’s to exploit. Sentech’s open proxy’s were found by these persons and the "free ride" was advertised for all and sundry to use at will.
So the bottom line for all you MyWireless users: People in ZA and all over the world have been stealing the bandwidth you have been paying so dearly for. They have been able to do this because of Sentech's monumental bungling incompetence. And to really make this a comic tragedy, Sentech have been blaming the slow speeds you currently experience on YOU the MyWireless users for using too much bandwidth! Meanwhile, the real problem has been that Sentech have left their international pipeline open to use and abuse by all and sundry!
-Professional information anarchist-
www.sentechhatesfreespeech.org.za
I support:
www.hellkom.co.za
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