Cisco's Content Engine Network Modules for the Cisco 2600, 3600, and 3700 series routers offer the industry's first and only router-integrated content-delivery system, combining intelligent caching, content routing, and management with robust branch-office routing conserves WAN bandwidth for important branch IP services such as voice over IP (VoIP), while simplifying configuration, deployment, and operation. Running Cisco Application and Content Networking System (ACNS) Software, Content Engine Network Modules enable Cisco customers to extend the value of their branch router infrastructures to deliver strategic new application services - such as employee Internet management, streaming media, and live and on-demand e-communications and e-learning - with no performance degradation of core routing services. Further, the Content Engine Network Modules interoperate with all Cisco IOS routers, and take advantage of key Cisco IOS features such as multicast and Web Cache Control Protocol (WCCP), while supporting a common command-line interface (CLI).Content Engine Network Modules fit into a single network module slot on the Cisco 2600, 3600, and 3700 series. The network module with SCSI controller has no disk drive on board and requires an external disk array such as the Cisco SA-6.