Network

A network is viewed as the transport mechanism that conveys data from one point to another. TAPI service providers handle the specific protocols required to perform operations such as establishing a communications session on a given network. An end-user or server application normally requires only very general network information, such as address type.

Some common types of networks:

• POTS (Plain Old Telephone Service): Voice and data are transmitted in analog format while in the local loop and are digitally transmitted elsewhere. Typically, one media type per call, one channel per line.
• ISDN (Integrated Services Digital Network): Transmitted digitally. Speeds of up to 128 Kbps on Basic Rate Interface (BRI-ISDN) lines and much higher on Primary Rate Interface (PRI-ISDN) lines. At least three channels and as many as 32 channels, for simultaneous, independently operated transmission of voice and data. International standard.
• T1/E1: Transmitted digitally. T1 is a transmission link with a capacity of 1.544 Mbps, typically used for connecting networks across remote distances. In Europe T1 is called E1.
• Switched 56: Signaling at 56 Kbps over dial-up telephone lines, but requires special equipment. Limited to calls to other specially equipped facilities.
• CENTREX: Centralized network services through regular telephone lines and using telephone company equipment. No special equipment required.
• Digital PBXs (private branch exchanges) and key systems: Voice and data transmitted on private telephone systems using proprietary interfaces.
• IP Networks: Voice and data transmitted on networks using the Internet Protocol (IP), such as the Internet itself or a corporate intranet.

Please note that this list is not exhaustive. Any network transport mechanism can be supported, given appropriate service providers.