G
LOSSARY
Glossary-7
Private Branch Exchange (PBX)
A telephone exchange local to a particular organization w ho use, rather
than provide, telephone services.
Private VLANs
Private VLANs provide port-based security and isolation between ports
within the assigned VLAN. Data traffic on downlink ports can only be
forwarded to, and from, uplink ports.
Quality of Service (QoS)
QoS refers to the capability of a network to provide better service to
selected traffic flows using features such as da ta prioritization, queuing,
congestion avoidance and traffic shaping. These features effectively
provide preferential treatment to specific flows either by raising the
priority of one flow or limiting the priority of another flow.
Remote Authentication Dial-in User Service (RADIUS)
RADIUS is a logon authentication protocol that uses software running on
a central server to control access to RADIUS-compliant devices on the
network.
Remote Monitoring (RMON)
RMON provides comprehensive network monitoring capabilities. It
eliminates the polling required in standard SNMP, and can set alarms on a
variety of traffic conditions, including specific error types.
Rapid Spanning Tree Protocol (RSTP)
RSTP reduces the convergence time for network top ology changes to
about 10% of that required by the older IEEE 802.1D STP standard.