[asterisk-users] Disconnection supervision: what about PBX

[Stephen Bosch]

Trevor G. Hammonds wrote:
> Yuan,
> Well engineered analogue PBXs typically do not use standard loop start
> subscriber lines.  When digital trunks are not an option, they use analogue
> PBX and/or DID trunks.  At the very least, ground start circuits are
> preferred to avoid "glare".  The best call quality for analogue is achieved
> by using four-wire E&M trunks that provide answer and disconnect
> supervision.  There are two-wire trunks (which are probably more common), as
> well as different signalling methods.  These trunks require special
> interface hardware, and I am unaware of any that work with Asterisk.  As the
> cards are typically very expensive, it is usually better to go with digital
> if you require that functionality.  It would be nice to see a BRI interface
> for Asterisk that works in North America, as BRI circuits are often
> comparable in price to analogue lines.  

Are BRI circuits what phone companies call "digital" lines for use with
digital sets, such as with digital Centrex?

I'm not aware that Telus even offers BRI.

-Stephen-