dry pair

Fri Aug 29 23:43:37 UTC 2003

At 23:03 29/08/2003, Joel Jaeggli wrote:

>On Fri, 29 Aug 2003, Patrick Felt wrote:

[snip]

> > If not,
> > how would the alarm company get the signal pushed through the fiber, and
> > could that be done with the dsl signal?
>
>The alarm companies need to deliver extremely small amounts of data which
>can range from make or break circuits to 60 300 or 2400bps data for things
>like building control systems, that's a considerably different problem
>than try to ram 1-7mb/s through a 25,000 foot long piece of wire.

Not necessarily, the bit rate may be higher. Good modern alarms use a 
cryptographically secured bitstream to provide the anti-tamper part of the 
line protection. A cryptographically useful message size with a reasonably 
short delay between 'raise alarm' and 'indicate alarm' requires a fair bit 
rate.