[Asterisk-Users] What's the difference?

[Steven Critchfield]

On Thu, 2004-09-30 at 20:11, Lyle Giese wrote:
> The orginal use for these was to extend dialtone over a channalized T1
> between towns.  In the old days, businesses would buy phone numbers in a
> different town/phone exchange and port it to their offices.  This was way
> before call forwarding was popular or practical dues to long distance rates
> at the time.
> 
> At the orginating end, we would put in a Foreign eXchange Office channel
> unit and wire it to the local dial tone port on the telco switch.  At the
> other end, we would put in a Foreign eXchange Subscriber channel unit and
> wire it to a cable pair that went to the business that purchased that out of
> town(or Foreign eXchange) dial tone.
> 
> An FXO gets dial tone from somewhere and the FXS faces the subscriber
> equipment/phones/stations.

Dialtone is only for the humans. An FXO port is a non powered port and
is plugged into a line with power on it. FXS provides battery power to
the line. FXS can provide ring voltage and FXO can not.


-- 
Steven Critchfield <critch at basesys.com>