Configure your connections to telephone service providers, including VoIP providers and traditional phone company (telco) providers. Several Barracuda Phone System models have built-in hardware for telephone service connections: analog lines for the 270B and PRI circuits for the 370B, 470B, and 670B models. You can also connect the Barracuda Phone System to external systems such as other Barracuda Phone System units or legacy PBX systems. See Connecting to Another PBX or SIP Server for more information.
A connection to a VoIP provider is sometimes called a gateway. This is not an IP gateway like your subnet’s default gateway. When discussing call routing, the term gateway almost always refers to a connection to a VoIP provider. It can also refer to a VoIP connection to another PBX.
When configuring connections to telephone service providers (whether VoIP, PRI, or analog lines), you must consider how calls are routed in the system. This includes incoming calls made to Direct Inward Dialing (DID) numbers and outbound calls going out to providers.