Cisco Content Engine 500 series units are Internet content delivery devices that offer content caching, hosting, and other content-based services. The Content Engine sits on the WAN edge between your small business site, enterprise, or service provider network and the Internet.The Content Engine 590 (CE-590) is a high-end Content Engine that services Internet service providers and large enterprise networks. The Content Engine sits on the WAN edge between your large enterprise or service provider network and the Internet and is designed to handle DS-3 traffic at 45 Mbps speed. The CE-590 is configured for AC-input power, whereas the CE-590-DC is configured for DC-input power. The default factory configuration comes with one power supply installed. The CE-590 has two internal 18-gigabyte (GB) Ultra2 LVD SCSI hard drives and an external SCSI port for attaching a six-drive Cisco Storage Array that increases the Content Engine storage capacity by an additional 108 GB (6 x 18 GB).