The Cisco DT-24+ digital gateway provides a connection path between the Cisco AVVID (Architecture for Voice, Video and Integrated Data) packet telephony network and the Public Switched Telephone Network (PSTN) or a PBX using digital (PRI ISDN) trunks. The DT-24+ supports 23 voice channels on a T1 interface. Gateways are managed, controlled, and administered through the required Cisco CallManager. The DT-24+ gateway consists of a single PCI bus-based card and mounts in any PCI bus PC (where it only draws power).When deployed in a network, the DT-24+ Digital Gateways can be located in any convenient PCI bus-based PC. They simply draw power from the host PC and are completely managed via browser access through the Cisco CallManager. Because they only draw power, they do not affect the performance or operation of the host PC, nor do they require any special software or drivers. The DT-24+ communicates with the Cisco CallManager, which allows the implementation of supplementary services such as hold, transfer, and forward on outside calls.