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.Cisco offers 2524/25 ISDN-BRI (Basic Rate Interface) with U bus Interface that allows you to increase the bandwidth speed up to 128 kbps.