Question regarding UK telephone extension wiring & DSL internet
connection. Probably best answered by a researcher with some
familiarity or comfortableness with UK telecom installation / DSL
internet provision?
I need an answer to this particular question before I leave for work
in the morning, which will be at 0700 GMT (7am UK time) Friday 24th
Jan.
Customer has one standard incoming telephone line, supplied by British
Telecom. It is terminated by a standard BT NTE capacitor linejack.
Customer accesses the Internet over this line using DSL (data signal
superimposed on the voice pair).
Recently she had 2 extension sockets added:
Standard 4-pair cabling was stapled along skirtings from the BT NTE,
for a distance of 10 metres, to additional socket number 1, which was
type lj2/1a (standard 'master', or capacitor, socket). The new cable,
(blue) pair number 1, was connected directly across the screw
terminals of the incoming line at the NTE, & the same (blue) pair was
connected to the new additional socket number 1 using terminals 2 & 5.
Similar wiring was then run from additional socket number 1, to
additional socket number 2, using the blue pair to connect the second
additional socket to the first additional socket, pin 2 to pin 2 and
pin 5 to pin 5:
--------------2----------/---------2-----------------------2
--------------5--------------------5-----------------------5
line in.....bt nte...........new socket 1............new socket 2
With the new setup as above, the customer cannot access the Internet
using her DSL connection from any socket, although all three phone
points operate for voice or standard dial-up 56k internet connection.
A 'stopgap' solution has been found; a make-break single pole switch
type 2a has been fitted in the line between the NTE and additional
socket 1. using this, the customer can disconnect one leg of the pair
feeding the two new extensions. By this means, she may use the
Internet connection from the NTE, but loses the use of the 2 new
extension sockets whilst online.
Her DSL connection seems to be of the following format: a small box,
about the size of a matchbox, which has a standard BT plug on a flying
lead, plugs into the phone point. The small box itself has two
sockets: one to plug a standard pot or slt type phone in, for voice,
and an (rj45?) socket into which a (patch lead?) from the Internet PC
plugs. It is labelled 'DSL filter' and is identical in general
appearance to a junction box BT78a.
My job tomorrow is to arrange the wiring in such a way as to provide 3
permanently working voice phone points, any of which may be used if
and when desired to access the Internet via DSL, by plugging in the
DSL filter.
My guess, and it *is* a guess, having little experience with DSL, is
that the capacitors in the two additional sockets are somehow
interfering with the DSL signal. I'm planning on replacing the two
additional sockets with type 3/1a, slave sockets containing no
capacitor, and wiring pin 3, the ringer output, from the NTE, through
to pin 3 on each new extension in addition to the '2&5' speech pair.
Is my guess as to the cause of her problem (too much capacitance
across the line) likely to be correct, and is the solution I propose
likely to work, or, am I barking up the wrong tree?
The newsgroup uk.telecom might help in answering, or, if you have the
required knowledge I'm happy to accept a personal knowledge, rather
than research, based answer. |
Request for Question Clarification by
sublime1-ga
on
23 Jan 2003 16:51 PST
gan...
I'm not sure how well this translates to a British system,
but when I used a local American DSL service, the configuration
was as follows:
The DSL 'modem' card acted as a 'DSL filter', of itself, and
so was plugged directly into an outlet. A phone could then
be plugged into the card itself, which served as a filter.
All other wall outlets (to which a device of any kind - phone
or fax - was attached) had to have a DSL filter placed in line
between the wall and the device.
The way I'm understanding your description of her setup is that
she has her computer (that is, the DSL modem) plugged into a
DSL filter which is then connected to the wall socket. In the
American system, this is specifically stated to be unnecessary,
and likely to cause problems.
Given this, and assuming it translates to the British system,
I would first remove the DSL filter between her wall jack and
her computer's DSL modem card, and use a straight connection
(and test it with the inline switch open). If that works, I
would then close the switch, with no devices connected to
'new socket 1' and 'new socket 2'. If the connection remains
functional, I would then connect a phone to 'new socket 1
or 2' with a/the DSL filter in between the phone and the
socket. If that works, as I believe it should, it just
remains to add another DSL filter to the second new socket
prior to adding a phone to that socket.
Let me know if all of the above makes sense to you, and if
you try it, let me know the results.
sublime1-ga
|
