3/2     If I subscribe to DSL, I can connect to the internet and talk on the
        phone at the same time.  Does that mean I can connect via DSL on one
        machine and connect via a dial-up modem on another machine at the same
        time?  Thanks.  -- yuen
        \_ Assuming you install the frequency filter they gave you, yes.
           \_ I hearby officially announce my ignorance on the subject.
              What is a frequency filter and how is it installed? It was
              expecting something like htonl for floats.
              \_ Non authoritative primer on DSL - DSL utilizes the same
                 copper that dial-up modem (traditional voice) does.
                 However, instead of an analog signal it sends over a
                 digital signal. DSL also does not utilize a modem, as
                 modulation and demodulation of a digital signal is
                 not required. DSL utilizes a very high frequency range
                 that is typically not used by traditional voice
                 communications. However, you can still hear the interference
                 from the high frequency, (probably due to the usual
                 frequency enhancing/cancelling/echoing/etc. which I
                 can't comment on) and so to prevent that from occurring
                 they've designed a frequency filter which filters out the
                 DSL signal. This allows you to talk on the phone without
                 having an annoying hiss in the background. I'm not
                 sure if the hiss will affect a dialup modem's signal
                 (it probably does), but you'll definitely want to install
                 one regardless.
                 \_ DSL utilizes frequency above the voice band.  The filter
                    /hybrid is used to filter out the high freq noise for
                    your phone.  In adsl, digital data is modulated
                    through a IFFT/FFT.  Signals are then converted to analog
                    and blasted through the copper wire through a transceiver.
                    \_ So the $19.99/mo "DSL" that SBC Yahoo sells is actually
                       ADSL, right?
                 \_ sorry, DSL uses modems.  the modulation standard is, for
                    example G.lite, and occupies a different spectrum so
                    that this trick w/ a low-pass filter allows the line
                    to be shared with a POTS signal that has its own specific
                    band-pass characteristics.  what's interesting is that
                    the DSL modem can tolerate the high voltage ring indication
                    without any disruption of service.
              \_ It's simple, they give you a bunch of filters, you install one
                 on each of your phone outlets EXCEPT the DSL one.
              \_ I like to point out that, despite the filter, it somehow fried
                 one of my Panasonic fax machine twice. If I connect my fax
                 to my normal line, it will operate fine. If I connect to DSL
                 line with filter, after a few weeks, the machine will act up
                 weired, after a few months, it stopped working. It was during
                 warranty period, so they replaced the whole board. But after
                 a few weeks, it started to act weired again. So now I have
                 comcast and the fax works fine. I think the filter is far from
                 perfect.
                 \_ Would daisy-chaining the filters for the fax machine help?
                    -- yuen