3Com CoreBuilder 9000 User Manual page 453

G 453
LOSSARY
Partial Packet Drop A procedure for discarding cells related to one user frame to minimize
the impact of congestion.
(PPD)
Port Status LED LEDs that indicate the status of each port.
Software Error LED LEDs that light up in a binary pattern to indicate the nature of the
software error.
Software State LEDs that pinpoint the stage of the software execution at which the
Indicator LED failure occurred.
Synchronous Digital An ITU-T defined hierarchy that standardizes the signal interfaces for
Hierarchy (SDH) very high-speed digital transmission over optical fiber links.
Synchronous Optical An ANSI-defined standard for high-speed and high-quality digital
Network (SONET) optical transmission.
traffic management A mechanism for preventing congestion or other traffic flow problems
in a network, by means of performing a set of actions for managing
the traffic.
User Network The interface, defined as a set of protocols and traffic characteristics,
between the CPE (user) and the ATM network (ATM switch).
Interface (UNI)
VCI Virtual Channel Identifier. Part of the identifier of a particular virtual
circuit in the ATM fabric.
VPI Virtual Path Identifier. Part of the identifier of a particular virtual circuit
in the ATM fabric.
WAN Wide Area Network. Data communications network spanning very large
geographical areas.