(1) See network access server.

(2) (Remote Access Service) A Windows NT/2000 Server feature that allows remote users access to the network from their Windows laptops or desktops via modem. See RRAS and network access server.

(3) (Registration, Admission and Signaling) In an H.323 audio or video system, the RAS is a control channel over which H.225 signaling messages are sent. It provides a central point that all devices monitor for an incoming call signal. See H.225 and H.323.

(4) (Reliability Availability Serviceability) Originally an IBM term, it refers to a computer system's overall reliability, its ability to respond to a failure and its ability to undergo maintenance without shutting it down entirely.

(5) (Row Address Strobe) A clock signal in a memory chip used to pinpoint the row of a particular bit in a row-column matrix. See CAS.