Digital Port Cards

NOTE: Each voice channel represents a digital trunk into the Plexus system.

T-1/E-1 CAS Digital Trunk Interface Card Channel Associated Signaling (CAS) is a generic name for a signaling method used on T-1 and E-1 carriers. T-1 uses Robbed Bit Signaling (RBS). This method utilizes all 24 channels for voice, data, and signaling, offering 24 voice channels for the Plexus system. E-1 provides 30 ‘clear’ channels for voice. The two remaining channels are reserved for framing and signaling.

ISDN PRI Digital Trunk Interface Card ISDN PRI is an interface between a user and a digital telephony network capable of delivering many types of services. PRI can be implemented on either a T-1 or an E-1 carrier. In both cases, the full bandwidth of the bearer or B-channels is available for the transmission of voice. T-1 ISDN PRI offers 23 voice channels. E-1 ISDN PRI offers 30 voice channels.

ISDN BRI Digital Trunk Interface Card ISDN BRI is a communication protocol that utilizes existing local loop wiring (i.e., standard 2-wire, single pair) to carry a digital signal. This signal can be split into two separate voice or data channels. A four port ISDN BRI card offers up to eight voice channels.

Digital Extension Interface (DEI) The Digital Extension Interface card provides 8 digital extension ports. These ports are designed to operate with the Plexus Digital Key Telephones. Due to the digital signaling, these ports are not compatible with Plexus Analog Key Telephones or other analog phone devices (see Analog Extension Interface).