The Cisco 7505 router supports multiprotocol, multimedia routing and bridging with a wide variety of protocols and any combination of available electrical interfaces and media. Network interfaces reside on interface processors that provide a direct connection between the CyBus in your Cisco 7505 and external networks. The Cisco 7505 has five slots: four interface processor slots (0 through 3) and one slot for the Route Switch Processor (RSP1 or RSP4). The Cisco 7505 uses a single power supply, with two models available: DC input or AC input. The front, or noninterface processor end of the Cisco 7505 has a removable panel that is secured with two captive fasteners. Removing the panel provides access to the internal components: the power supply and fan tray.