Center City Communications offers traditional PRI (Primary Rate Interface) circuits, which utilize a traditional AT&T copper network via a T-1 circuit and is now available over a coax cable network.

PRI typically offers 23 B channels and a D1. The D channel manages the other 23 channels, which allow for 23 simultaneous inbound and outbound calls. 

The circuit can be leveraged by adding Direct Inward Dial (DID) and Direct Outward Dial (DOD) numbers, which can usually accommodate up to 200 employees in a single facility, by using a single circuit.

Partial PRI is also available with individual channels and trunks. Having individual trunks linked to the DID/DOD is useful and cost-effective for companies that don't need a full PRI, including those that have a smaller workforce. It can be useful to help set up and use an IP-based phone system.

IP Based PRI

Center City Communications offers an IP (Internet Protocol) PRI. It is remarkably similar to SIP (Session Initiated Protocol) trunking. It allows IT managers to scale up or down the trunk they need for their organization, which provides them with extreme flexibility.

IP-PRI uses an IP to connect to the TDM network where the carrier will supply equipment to convert Session Initiated Protocol into PRI Signaling.

IP-PRI are much less expensive and easier to deploy than a TDM PRI, but it depends on Internet connectivity, while copper is more expensive but more reliable.