Similar for cable: it's a down conversion and extraction of the modulation from a carrier. Modem is the proper term for both types, since they extract (demodulate) from one spec to another and different IEEE composite signal . "Bridge" is not. > -----Original Message----- > From: tclug-list-bounces at mn-linux.org > [mailto:tclug-list-bounces at mn-linux.org] On Behalf Of steve ulrich > Sent: Thursday, January 16, 2014 8:12 AM > To: TCLUG Mailing List > Subject: Re: [tclug-list] recommendations for linux router devices > > at the risk of being pedantic DSL is a digital *service*. it still > uses high frequency carrier wave modulation (analog signal > transmission) to transmit the data. hence the use of > modulation/demodulation technology. ADSL happens to modulate > frequencies on the line which are outside the normal phone spectrum > and it's this spectral separation that allows co-residence with > standard analog voice services. other flavors do/don't allow for this > but operate on largely the same principles. signal processing is a > wonderful thing. > > On Thu, Jan 16, 2014 at 7:55 AM, Carl Wilhelm Soderstrom > <chrome at real-time.com> wrote: > > On 01/15 07:33 , Jay Kline wrote: > >> I thought anything that modulated an analog signal to a > digital signal (and > >> the reverse) was a modem. It may not be audible, but it is > an analog signal. > > > > But in the case of a DSL or cable Internet connection, it > is digital on the > > wire. (Arguably I suppose in the case of a POTS telephone > connection it uses > > discrete tones, so could be called 'digital' since it > doesn't use a smooth > > wave). > > > > -- > > Carl Soderstrom > > Systems Administrator > > Real-Time Enterprises > > www.real-time.com > > _______________________________________________ > > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > > tclug-list at mn-linux.org > > http://mailman.mn-linux.org/mailman/listinfo/tclug-list > > > > -- > steve ulrich (sulrich at botwerks.*) > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > tclug-list at mn-linux.org > http://mailman.mn-linux.org/mailman/listinfo/tclug-list >