| Another
FAQ inspired article because many a person has asked about the subject,
this time the situation regarding fitted security alarm systems
and compatibility or incompatibility with ADSL service, and on how
to arrange for filtering them.
"Alarm systems are incompatible with
ADSL." - Not True!
These words are often uttered by BT, BT Broadband, and ISP's when
you call them. Most of the time, it's not actually true, but in
the Real World, we're in agreement with them that it's their best
policy to tell Joseph Public this. Remember that most people signing
up to broadband have little clue about telephone wiring, they just
want to plug it in and surf. The very fact that you're reading this
article suggests that you're not one of the Grazing Cattle Consumer
family. 
But it's VERY VERY IMPORTANT that you understand WHY they tell you
this so read on!
First, lets get the easy bit out of the way
- when IS an alarm incompatible with ADSL, and when is it not?
Redcare is a very specific BT product which monitors
the line 24/7 and alerts the control center in the event of the
line being cut or similar. Redcare keeps a constant signal on the
line to do this.
Previously this system was completely incompatible with broadband
use on the same line, but fortunately good old BT have now changed
things so that Redcare and Broadband can peacefully co-exist.
Redcare connections installed since 31st July 2003
are broadband compatible.
Redcare which was installed prior to that date remain incompatible,
but will begin to be made compatible in early 2004. Until
then line checks will continue to report an incompatibility.
You can find specific BT information on the subject at http://www.redcare.bt.com/security/products/adsl.htm
 To
add some confusion, lots of people say they have a "monitored
alarm system" meaning an alarm box which, upon an alarm trigger
event, dials the monitoring center automatically (just like an autodialing
modem) and tells them there's something happening. These alarms
are what most people have. This kind of alarm is,
for broadband compatibility purposes here, just another bit of plain
old telephone equipment, and is to be treated as such - same as
your phones, your faxes, your SKY box, your dial up modems. Autodialler
alarms must be on the filtered side of an ADSL filter/splitter device
and NEVER directly connected to the unfiltered exchange line. Read
on...
Autodialer
alarms and ADSL
Alarms with autodialers are no big deal to ADSL.
They just dial a number and deliver an ID and an alert to the alarm
monitoring service center.
Since it's a standard telephony device, that means you need to include
it in your ADSL filtering/splitting plans.
Whether you do that with the BT ADSL Adaptor for your NTE5 master
box, or arrange something with microfilters is of course up to you.
But it MUST pass through an ADSL filter or it and ADSL will interfere
with each other's operation.
The
Trouble With Hardwired Autodialer Alarms
The alarm should ideally be wired directly to the
master socket as a normal extension, although there's
no real functional problem if it's hardwired to a secondary extension
point elsewhere. This means that it's connected to the BT Exchange
Line on YOUR side of the master socket. This is VERY important.
Unfortunately, some alarm installers appear to think it's "ok"
to hardwire the alarm connections onto the BACK of the NTE5 box,
effectively directly onto the BT Exchange Line, and bypassing the
all-important master line box which marks the official demarcation
point between you and the public telephone network.
This practice is bluntly inexcusable.
FIRST it's illegal. YOU are
responsible for what's effectively tampering with your BT line,
not your alarm company - so YOU are liable.
SECOND it means that a BT
engineer is unable to make a completely uncontaminated test on the
exchange line via the test socket in the NTE5 unit - which is the
whole point of the NTE5 type unit!
And then we have...
THIRD It means that no amount
of microfilters or master box adaptors is any use for filtering
your alarm if you choose to have ADSL. Without filters there IS
an incompatibility because the alarm and ADSL will pi$$ each other
off no end.
So, given that BT has no way to be sure if your alarm is properly
or illegally installed, it's our feeling that they're quite right
to take the blanket approach and tell consumers that wired alarms
and ADSL is incompatible. Imagine the AMOUNT of hassle they'd get
if they told you it was compatible, and it turned out that YOU have
an illegal alarm installation - because for starters none of their
technical support helpdesk people are going to be able to diagnose
the problem. But you know as well as I do that Johnny Consumer would
proceed to BLAME BT or the ISP for the dropped connections that
would ensue, or when the alarm failed to alert the control center...
Conclusions...
REDCARE service installed prior to 31st July 2003 is absolutely
incompatible with broadband service until at least early 2004. Until
then, you NEED a separate line for each.
Alarms with telephone connections are to be treated like telephones,
same as SKY boxes.
All telephony devices MUST be filtered to work in harmony with ADSL
service,
so this includes autodialer alarms.
If you can provide filtering for your alarm as you would any other
telephone device, then you can have the alarm and ADSL on the same
line.
If you find your alarm has been illegally hardwired to the rear
of the master box instead of to the consumer permitted front plate
(assuming an NTE5 type master) then call your alarm supplier and
insist they correct the illegal wiring. For the avoidance of doubt
NOBODY but BT personnel may work on the public telephone network
wires behind the master socket (just in case your installer claims
they're "certified" to do so or something like that).
Note: this would mean the installer having to AGAIN
work on the master box to correct the wriing, AGAIN illegally -
so technically the correct advice is to call BT, have a BT engineer
site visit and have THEM correct the wiring, then claim the cost
of this back from the installer. It's up to you how you proceed
in this circumstance, but there's the facts of the matter for you
to consider.
Understand WHY BT/ISP's have to often generally list alarms as "incompatible
with ADSL" and don't give them hassle them about it. They're
only doing their job in the best way to suit the masses. Even though
you've been clueful enough to read up on this,
and can resolve any potential alarm wiring issues for yourself,
remember most of the broadband-using Public At Large have no idea
about such things. If you're happy to deal with your alarm wiring
arrangements now, then its best just not to mention it to your prospective
broadband ISP at all!
Above all else, it's extremely important that you now get your credit
card out and buy something from our lovely website.  |
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