_________ SWAT MAGAZINE ISSUE SEVENTEEN: MAY 1999 __________ / \___________________________________________/ \ / Asymettric Digital Subscribers Lines \ / By Unknown Guest \ ----------------------------------------------------------------------- This article is written by Unknown Guest the new member to SWATeam so if it is a bit shit you'll know why. Now i want to tell/inform you about the ADSL. Now ADSL was "probably" brought out to combat the failiure of Home Highway. Home Highway was BT's attempt to make ISDN a home useage. Home Highway failed because it defeated the object of having an ISDN line. What is the object of having an ISDN line?? Well, ISDN uses normally fibre optics to obtain the fast (relatively fast connection compared to a modem) data connection it has. But with home highway the connection uses some shit copper wiring connection same as the usual telephone wire stuff. A bit shit. If you dont know what ADSL (Asymettric Digital Subscribers Line) is, well it is a new technology launched by BT about 4 months ago and is currently on trial in London (west). The ADSL trial requires a BT engineer to come round to install the equiptment and then another engineer comes round to install the 10mbs network card (NE2000 compatible) and the software. Now the hardware engineer install a ADSL modem, a router and some other box not too sure what is does yet. The router is connected directly upto a coaxial cable which runs down the side of the house and into the main BT personnal box. The router is also connected upto the main telephone number in my case 0181-xxx-xxx. The router is present to direct the calls so you dont get a engaged tone when someone decides to call your telephone number. Well the router inside you house is directly connected to the modem using a RJ45 cable. Then the modem is connected upto your NE2000 card using another RJ45 cable but this time the cable is crossed over on pin 8 from 1 i think. The technology looks a bit like this layed out: ---- -------- -PC-_____------____- MAIN -___-------___-------_______----- ---- ------ -------- -VIDEO- -CACHE- -WWW- ------- ------- ----- PC>ADSL MODEM>MAIN MAIN TERMINAL>VIDEO SERVER>CACHE> WWW What type of speeds do i get with ADSL?? Well on a good day and a good server i am able to download (downstream) speeds of upto 300k/sec, sorry that is a bit of an exageration. I ONLY get about 250k/sec. And when recieving data from a webpage through port 80 i get about 2Mbps. These speeds do fluctate hurgely: "the connection is only as fast as the computer you are connected to" As the saying goes!! Now ADSL is so fast due to the special cache using a remote server where it stores all the previously visited webpaged. This brings fast access to all of the users. There are also lots of different servers including video,push,gaming. All of these bring the large speed increase to ADSL. Another advantage with the ADSL connection is that there are no call charges yes the £200/month phone bills have gone. For £30/month you get the highspeed connection and the unlimited calls but BT might start to monitor the number of megs you download. Now if youre thinking that is ok i dont download many megs during the month anyway well this limit includes the number of megs you download from the webserver. So this will severely limit the point of ADSL. Now those are the advantages of ADSL now for the disadvantages. Now i was slightly pissed off that the BT engineer took 2 months to come round to my house but i have to say it was worth it. Plus the other BT engineer took 3 months to come round and install the software and network card that i could have done myself. Basically the settings go along the lines of: DNS server Client IP Gateway iP Proxy Pac etc.. BT said people using a different OS apart from win9x will be infringing the trial bounddaries and could be chucked off, they also said that ADSL wont work on any other OS anyway. Well thats a load of Bolllocks isnt it. I am currently using it on WinNT server and Linux. I havent got it to work with FREEBSD yet but i am fucking close. So BT fuck you. If you live in London (West) you should consider getting it. For more info on it. go to: http://www.btinteractive.com/Registration http://www.adsl.com/ If youre a yank and you want to know more about the hardware and stuff, check out this link. http://www.3com.com/solutions/dsl/dsl_product_line.html Other new connections are cable modems. More info on them soon. m adding this end section onto the article cause a week ago before this article was published i found out what the prices are likely to be for ADSL. Well, BT said that there would be a one off fee probably in the range of £600-1000! then the cost will be about £40-45 per month for the usage If anyone has any knowledge about C programming it would be much appreciated. I am currently trying to recompile the NAT program to work with a list of hosts. Cheers. If you want to ask me something Im at email:unknown.guest@swateam.org ICQ: 16735367