The Cisco Channelized T1/E1 and ISDN PRI High-Speed WAN Modules combine multiple T1/E1 WAN connectivity-Channelized T1/E1 and ISDN Primary Rate Interface (PRI), in the same card. With flexible WAN connectivity options, together with integrated routing, security, voice, and wireless capabilities, Cisco Integrated Services Routers can meet every need of enterprise-class branch offices today and in the future. The integrated channel service unit/data service unit (CSU/DSU) function allows customers to consolidate customer premises equipment (CPE).