3Com 7000 manual

GLOSSARY 139

SVC Switched Virtual Connection. A standard signaling protocol that automatically defines connections as they are needed, and discards them when complete.

switched virtual LAN A logical network consisting of several different LAN Emulation domains controlled through an intelligent management application.

switching module A CoreBuilder 7000 switching module found in the slot just under the power supply. An additional switching module can be used for redundancy. The switching module contains a control port, a management port and a service port.

synched external Port that has been synchronized according to the external clock clock port supported by the external clock source port. Only on-board 8-port ports

can function as synched ports. Ports that are to be synched should be configured to internal clock mode.

T

topology database The database that describes the topology of the entire PNNI routing domain as seen by a node.

topology The physical or logical placement of stations on a network in relation to one another.

traffic management The aspect of the traffic control and congestion control procedures for ATM. ATM layer traffic control refers to the set of actions taken by the network to avoid congestion conditions. ATM layer congestion control refers to the set of actions taken by the network to minimize the intensity, spread and duration of congestion.

U

UBR Unspecified Bit Rate. UBR is an ATM service category which does not specify traffic related service guarantees. Specifically, UBR does not include the notion of a per-connection negotiated bandwidth. No numerical commitments are made with respect to the cell loss ration experienced by a UBR connection, or as to the cell transfer delay experienced by cells on the connection.

UNI User-Network Interface. An interface point between ATM end users and a private ATM switch, or between a private ATM switch and the public carrier ATM network defined by physical and protocol specifications per