[asterisk-users] Maximum cable length for analog phone from FXS port

[Lyle Giese]

asterisk-users at rogg.is wrote:
>
> Hello.
>
>  
>
> I am looking for details of the maximum allowed/usable/effective
> wire/cable length of the connection from a FXS port of Digium analog
> cards to the analog telephone handset.
>
>  
>
> To clarify my intention, I need to have an analog telephone connection
> to my asterisk box that is 3000 meters (3km) away at least. If you
> have any details of ATA boxes or other similar devices that I could
> use to do this, I'd appreciate your input. It must be able to use a
> regular analog telephone handset on the far end.
>
>  
>
> I've searched high and low and either I'm not clever enough in using
> the right terms for this or it is rarely documented?
>
>  
>
> Any details much appreciated.
>
>  
>
> Thank you!
>
> Baldvin
>
>  
>
It's not expressed in distance.  They will supply the current & voltage
output and you need to apply ohm's law.  That requires knowing the
resistance of the cable which is dependent on length and gauge.

Lyle Giese
LCR Computer Services, Inc.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20090526/f45b27b1/attachment.htm