Cisco IPS-4255-K9 Installation Guide - Page 388

Glossary promiscuous delta PD. A weight in the range of 0 to 30 configured per signature. This weight can be subtracted from the overall risk rating in promiscuous mode. promiscuous mode A passive interface for monitoring packets of the network segment. The sensing interface does not have an IP address assigned to it and is therefore invisible to attackers. Q Q.931 QoS ITU-T specification for signaling to establish, maintain, and clear ISDN network connections. quality of service. Measure of performance for a transmission system that reflects its transmission quality and service availability. R rack mounting Refers to mounting a sensor in an equipment rack. RAM random-access memory. Volatile memory that can be read and written by a microprocessor. RAS Registration, Admission, and Status Protocol. Protocol that is used between endpoints and the gatekeeper to perform management functions. RAS signalling function performs registration, admissions, bandwidth changes, status, and disengage procedures between the VoIP gateway and the gatekeeper. RBCP Router Blade Control Protocol. RBCP is based on SCP, but modified specifically for the router application. It is designed to run over Ethernet interfaces and uses 802.2 SNAP encapsulation for messages. reassembly The putting back together of an IP datagram at the destination after it has been fragmented either at the source or at an intermediate node. recovery package An IPS package file that includes the full application image and installer used for recovery on sensors. regex See regular expression. regular expression A mechanism by which you can define how to search for a specified sequence of characters in a data stream or file. Regular expressions are a powerful and flexible notation almost like a mini-programming language that allow you to describe text. In the context of pattern matching, regular expressions allow a succinct description of any arbitrary pattern. repackage release A release that addresses defects in the packaging or the installer. reputation Similar to human social interaction, reputation is an opinion toward a device on the Internet. It enables the installed base of IPS sensors in the field to collaborate using the existing network infrastructure. A network device with reputation is most probably malicious or infected. risk rating RR. A risk rating is a value between 0 and 100 that represents a numerical quantification of the risk associated with a particular event on the network. The risk of the attack accounts for the severity, fidelity, relevance, and asset value of the attack, but not any response or mitigation actions. This risk is higher when more damage could be inflicted on your network. GL-16 Cisco Intrusion Prevention System Appliance and Module Installation Guide for IPS 7.0 OL-18504-01