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March 13, 2007
Digital Telephone Service
There are a lot of companies marketing
Digital Telephone Service. Digital telephone is a method of taking analog audio signals, like the kind you hear when you talk on the phone, and turning them into
digital data that can be transmitted over the Internet.
Also known as VOIP, or Voice Over Internet Protocol, it is
an alternative to POTS lines (Plain Old Telephone Service),
and many times cheaper and/or provides for unlimited calls
for a flat rate per month. There are different
marketing names used for VOIP, such as "Digital Voice", or
"Vonage". but it is all based on VOIP.
However, with VOIP comes with some landmines that
the consumer needs to be aware of. First and foremost,
if you're going to use it with your alarm system for
reporting alarms, you should know that alarm manufacturers
do not recommend it. The reason is, the alarm
signal was designed to be sent to the alarm receiver in real
time. It's kind of like having a conversation with
someone sitting across the table from you - when you speak
to them, you speak directly to them and they reply directly
back to you. Using this example, with VOIP, a
conversation with someone sitting across the table from
you would
require you to
speak to the person sitting next to you, who relays the
message to the person next to him and so on until
the message gets to the person at the other end of the
table. The reply comes back to you in the same manner.
When you think of broadband internet service,
you think of high speed, cutting edge, state of the art
service that will transmit a web page around the globe
in seconds. And while that might be true, it's also
true that this data is sent in "packets" that can take
infinite routes to get from the sender to the receiver.
That is the underlying reason that VOIP isn't recommended
for alarm transmission: The timing of these packets is
not consistent, and it is possible that your alarm signal will not be received at the
central station.
Many people with alarm
systems have VOIP installed anyway because they are not
aware of the alarm manufacturer's warnings.
And, many times there will not be any problems with signals
being received at the central station.
We at Inner Security
Systems, along with the alarm manufacturers (which, by the
way, includes all of the
alarm manufacturer's without exception) recommends that VOIP
not be used for alarm signaling.
We do, however, get calls nearly every day
from people who want VOIP service anyway. And we get
requests from our clients for us to talk to their installers
so they know how to wire the alarm lines. It puts us
in an awkward position of being asked to help the
cable company do something that we advise against.
It's a catch 22 for us, and regrettably there is nothing we
can do to help your VOIP installers.
We do have alternate solutions, such as long
range radio service, and also do sell internet
communicators, but because this is a service that we need to
subscribe to it is more expensive then regular digital alarm monitoring.
When you add these costs to the initial equipment
and installation costs, all of a sudden, VOIP isn't as cheap
as it appears to be.
If, after all the advice to the contrary, you
decide to risk using digital lines with your alarm system,
please run a test on your system before the installer
leaves. Call the monitoring center, identify yourself
with your user number and password, and ask them to put your
system in test. Then test the alarm system before the VOIP installers leave, so that if there are any problems,
they can fix them before they leave. Again, please
don't ask us to help your VOIP installers. We can
not help them do something we advise against doing.
We can help you in choosing an alternative
signaling method, should VOIP be a "must have". Please
give us a call to discuss alternatives!
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