On Mon, 25 Oct 2004 00:57:00 GMT, "John \"O\"" <(E-Mail Removed)>
wrote:
>From what I understand there is a main switchboard but my client informs me
>that there is a independant line available, if this is the case would it be
>only the one ADSL filter required ??
If the POTS (plain old telephone service) line goes through an
electronic switchboard, then DSL will not work. Same with lines using
Pair-Gain, SLC95, VoIP, and various digital multiplexers. You need a
POTS metallic connection between either the CO (central office) or the
RT (remote terminal) to do DSL.
You have two choices in wiring. You can use a splitter at the MPOE
(minimum point of entry) also known as the demarc (point of
demarcation), after the NID (network interface device). This is
generally best as it isolate the ratty inside wiring from the rest of
DSL part of the circuit. The wire going between the DSL modem and the
NID should be a "home run" or direct connection. The splitter has no
circuitry (except possibly a fuse in the Siecor/Corning incantation)
on the DSL side of the circuit. The rest of the phones connect to a
low pass filter in the splitter, thus isolating them from the DSL
modem at the high frequencies (30Khz -> 1.5Mhz) used by DSL.
Instruments can be added to the phone line without changing anything.
The other way is to use microfilters. These are exactly the same as a
splitter, but with limitations as to the number of POTS instruments
that can be connected to the microfilter. More simply, the low pass
section is not as good as the splitter. They're cheap enough that you
could, and should, attach one to every POTS instrument on the line.
That includes FAX machines, answering machines, satellite TV boxes,
CATV settop boxes, modems, computahs with modems, etc. The DSL modem
gets a direct connection to the line. The most common problem is that
someone adds a new instrument to the line, and forgets to install a
microfilter.
For installation with ratty or lengthy inside wiring, or for marginal
distances from the CO, or for VHDSL 6Mbit/sec connections, I recommend
a splitter. For the generic ADSL line, that's fairly close to the CO,
microfilters work well enough.
--
Jeff Liebermann
(E-Mail Removed)
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558