Just get several T1's from your Telco, each supports
24 simultaneous lines. You also get Direct Inward Dialing (DID's)
from them. YOu can have more numbers assigned than physical lines,
however as they all aren't in use at the same time.
The T1' interface to Asterisk with a T1 or Quad T1 card.
On the other hand if your doing VOIP, you just get
several DID's from any VOIP provider and don't need
any hardware ( just a fast Inter