Specifications

Glossary 317
RAID level A storage allocation scheme used for storing data on a RAID array. Specified
by a number, as in RAID 3 or RAID 0+1.
RAID set See RAID array.
Real Time Streaming Protocol See RTSP.
Real-Time Transport Protocol See RTP.
realm General term with multiple applications. See WebDAV realm, Kerberos realm.
relay In QuickTime Streaming Server, a relay receives an incoming stream and then
forwards that stream to one or more streaming servers. Relays can reduce Internet
bandwidth consumption and are useful for broadcasts with numerous viewers in
different locations. In Internet mail terms, a relay is a mail SMTP server that sends
incoming mail to another SMTP server, but not to its final destination.
relay point See open relay.
root An account on a system that has no protections or restrictions. System
administrators use this account to make changes to the system’s configuration.
RTP Real-Time Transport Protocol. An end-to-end network-transport protocol suitable
for applications transmitting real-time data (such as audio, video, or simulation data)
over multicast or unicast network services.
RTSP Real Time Streaming Protocol. An application-level protocol for controlling the
delivery of data with real-time properties. RTSP provides an extensible framework to
enable controlled, on-demand delivery of real-time data, such as audio and video.
Sources of data can include both live data feeds and stored clips.
SACL Service Access Control List. Lets you specify which users and groups have access
to specific services. See ACL.
scope A group of services. A scope can be a logical grouping of computers, such as all
computers used by the production department, or a physical grouping, such as all
computers located on the first floor. You can define a scope as part or all of your
network.
SDP Session Description Protocol. A text file used with QuickTime Streaming Server
that provides information about the format, timing, and authorship of a live streaming
broadcast and gives the user’s computer instructions for tuning in.
search path See search policy.
search policy A list of directory domains searched by a Mac OS X computer when it
needs configuration information; also, the order in which domains are searched.
Sometimes called a search path.