The Cisco Secure IDS-4210 Sensor is a network security "appliance" that detects unauthorized activity traversing the network, such as attacks by hackers, by analyzing traffic in real time, enabling users to quickly respond to security breaches. When unauthorized activity is detected, the sensor can send alarms to a management console with details of the activity and can control other systems, such as routers, to terminate the unauthorized session(s).The Cisco Secure IDS-4210 Sensor is optimized to monitor 45-Mbps environments and is ideally suited for monitoring multiple T1/E1, T3, and Ethernet environments. Sensors can be placed where other security devices may not be practical; for example: internal network segments, in front of a firewall, behind a firewall, behind a dialup modem server, and at extranet connections. Sensors may be placed on almost any network segment of the enterprise-wide network where security visibility is required.