Cisco offers a wide variety of connectivity, expansion and upgrade modules to accommodate the range of application needs in customer networks. The network modules assure customers that they can choose a connectivity solution that fits their requirements. As modular components, they are easily and inexpensively field upgradeable as customer requirements change.The digital signal processor (DSP) module contains 6 DSPs per module and provides voice compression and packetization services to the VoIP card so that you can configure and expand them.