■ Digital voice ports are found at the intersection of a packet voice network and a digital, circuit-switched telephone network.
■ T1 CAS use a digital T1 circuit together with in-band CAS.
■ E1 digital circuits can be deployed using R2 signaling.
■ ISDN is a circuit-switched telephone network system designed to allow digital transmission of voice and data over ordinary telephone copper wires.
■ ISDN uses Q.921 and Q.931 for signaling.
■ Before configuring a T1 or E1 trunk, you must gather information about the requirements for Framing, Linecode and DS0 gourps.
■ Configuring an E1 trunk is similar to configuring a T1.
■ Many PBX vendors support either T1/E1 PRI or BRI connections.
■ Various show commands are available to verify and monitor digital voice ports.
■ QSIG allow feature transparency between different vendor PBXs.
■ QSIG can be configured over PRI or BRI.
■ Various show and debug commands are available to verify the QSIG connection.
PR