GrandCentral via Asterisk

[JD Austin]

You could go all voip but I wouldn't recommend it unless you have a terrific
internet connection... even then it isn't always as good as a land line
except in my case where all of the land lines available are horrid (thanks
Qwest!).

Here comes the terminology overload.... :)

Inbound lines are called FXO and outbound ports are called FXS.  FXO ports
receive dial tone from the phone company.  FXS give dialtone to devices such
as a phone or fax.

Trunks are a block of lines.  Usually they come in on a PRI.  You can also
have voip trunks that give you a set number of concurrent connections with
the same DID (Direct Inward Dial) number.

To build an asterisk based system yourself you need a computer to run it on
(1.5GHZ+ Intel/AMD with 512MB+ of ram, 80G+ hard drive), hardware to
interface it with the PSTN (public switched telephone network) unless you're
oing all voip, and the asterisk bundle such as PBXInAFlash or Trixbox.
Keep in mind that many TDM cards generate a ton of interrupt requests and if
the irq it is using is being used by something else you can have all sorts
of audio quality issues.