Doug Crompton on Sat, 8 Jun 2002 05:38:07 -0400 |
Just to make it clear xDSL as it is often called refers to a multitude of formats. We are usually talking about ADSL -Asyncronous Data Subscriber Line - which has a maximum loop range of 12-15K feet from your CO. It will not work through a carrier system (SLC). There is a variety of xDSL that will go to 46K feet and work through Fiber or carrier systems and that is IDSL - which is a DSL version of ISDN. It runs at (usually) 142K in both directions. It does NOT have a voice band although there are formats that incorporate a voice phone connection. So there is a DSL for virtually everyone if the line provider is willing to provide it. At the moment Verizon will not qualify a line for any format beyond 18K feet. That is what I am in a battle with them over at the moment. www.crompton.com/Verizon-PUC/Verizon-PUC.html Doug > > Actually, no. The line from your home to the CO is NOT Digital. It really > is still analog, and will continue to be analog into the forseeable future. > If it really were a digital line, you would not be able to use an analog > modem (ie dial-up) on that line. That's why in may hotels you can't use > your modem -- they DO have a digital PBX. > > The line from your home to the CO is normally a "dry-copper" pair. If you > live in an apartment building or development, you may have a "green box." > in which case, the line is analog from your wall jack to that "green box," > where it is multiplexed together with "everybody else" onto a "T-circuit" > and shipped back to the CO. > > But analog is why you can have DSL service. DSL was developed as a > technique for providing digital service over an analog line. Similarly, > until they put the DSLAM in the "green box" at the curb, instead of at the > CO, people in many appartment buildings and developments can't get DSL > because they do have T-service into that "green box." > > T.T.F.N. > William H. Magill Senior Systems Administrator > Information Services and Computing (ISC) Networking & Telecommunications > University of Pennsylvania > magill@isc.upenn.edu magill@acm.org > http://www.isc-net.upenn.edu/~magill/ magill@mcgillsoceity.org > > > ______________________________________________________________________ > Philadelphia Linux Users Group - http://www.phillylinux.org > Announcements-http://lists.phillylinux.org/mail/listinfo/plug-announce > General Discussion - http://lists.phillylinux.org/mail/listinfo/plug > **************************** * Doug Crompton * * Richboro, PA 18954 * * 215-431-6307 * * * * doug@crompton.com * * wa3dsp@wa3dsp.ampr.org * * http://www.crompton.com * **************************** ______________________________________________________________________ Philadelphia Linux Users Group - http://www.phillylinux.org Announcements-http://lists.phillylinux.org/mail/listinfo/plug-announce General Discussion - http://lists.phillylinux.org/mail/listinfo/plug
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