the Pvdm4 Modules Are Supported On The Cisco 4451-x Platform. You Can Plug Them Directly Into The Single Slot On The Router Motherboard Or Onto The Network Interface Module (nim) That Supports T1/e1 Ports. Enhanced Dsp Architecture Accommodates A New Packet-processing Engine Optimized For Rich-media Voice Applications, While Concurrently Supporting The Time-division Multiplexing Ip (tdm-ip) Voice Framework. A Pvdm4 Module Plugged Onto The Motherboard Delivers Ip-based Voice Services Such As Conferencing, Media Optimization, And Transcoding. A Pvdm4 Module Plugged Onto The Nim Daughter Card Would Be Used For Voice T1/e1 Connectivity.all The Pvdm4 Modules Have The Same Form Factor And Are Field-upgradable To Allow You To Easily Scale Your Voice Deployments.