The Digital E1 Packet Voice Trunk Network Module provides a flexible and scalable E1 voice solution. A single packet voice trunk network module supports both on-premise and off-premise connections to both Private Branch Exchanges (PBXs) and Public Switched Telephone Networks (PSTNs). This product is ideal for enterprise branches, large businesses and service providers wishing to migrate to packet-based multiservice infrastructures. This network module leverages existing legacy telephony equipment investments in addition to providing the ideal gateway interface for IP telephony within the Cisco Architecture for Voice, Video and Integrated Data (AVVID). It also enables the deployment of new packet voice applications while reducing recurring telephony charges.