Motorola SURFboard SBG901, User Manual

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B Glossary 121
This document is uncontrolled pending incorporation in PDM
TERM DEFINITION
QPSK Quadrature Phase Shift Keying is a phase modulation algorithm. Phase
modulation is a version of frequency modulation where the phase of
the carrier wave is modulated to encode bits of digital information in
each phase change.
QoS Quality of service describes the priority, delay, throughput, and
bandwidth of a connection.
R
RAS Remote Access Server
registration How a cable modem makes itself known to the CMTS. The cable
modem configuration file and authorization are verified and the CoS is
negotiated.
return loss A measurement of the quality of the match of the device to the cable
system. Return loss is the ratio of the amount of power reflected by
the device. A return loss of 20 dB or greater is preferred.
RF
Radio Frequency — signals used by the CMTS transmitter and receiver
to send data over HFC. The carrier is modulated to encode the digital
data stream for transmission across the cable network.
RJ-11 The most common type of connector for household or office phones.
RJ-45
An 8-pin modular connector; the most common connector type for
10Base-T or 100Base-T Ethernet networks.
ROM read-only memory
router
On IP networks, a device connecting at least two networks, which may
or may not be similar. A router is typically located at a gateway
between networks. A router operates on OSI network layer 3. It filters
packets based on the IP address, examining the source and destination
IP addresses to determine the best route on which to forward them.
A router is often included as part of a network switch. A router can also
be implemented as software on a computer.
routing table
A table listing available routes that is used by a router to determine the
best route for a packet.