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List of terms
Nortel Multiservice Switch 7400/15000/20000
Terminology
NN10600-005 7.2S1 Standard
PCR7.2 and up March 2006
Copyright © 2006, Nortel Nortel Confidential
queue
A linked list of buffers that stores user or control data that is incoming or
outgoing from a processor card. The data can be in the form of frames or cells.
queue length
The number of blocks that currently make up the queue.
queue limit
The maximum number of blocks that can be attained by the queue length.
queue threshold
A specific number of blocks used in the determination of the congestion state
of the queue. A queue can define several thresholds. As the queue length
crosses each threshold, the queue enters a more severe congestion state. On
ATM FPs, each queue has three thresholds in addition to the queue limit.
SBIC FPs have up to four thresholds defined.
queue controller (QC)
The part of the shared bus interface controller that maintains the linked list
pointers, blocks, buffers, and queues of the shared memory. The queue
controller manages up to 256 queues.
queue relay device (QRD)
A cell-only hardware chip on certain Nortel Multiservice Switch ATM IP
function processors that provides traffic management functions such as per-
VC queuing and congestion control.
RAI
See remote alarm indication (RAI) (page 112).
RAIG
See resource availability information group (page 113).
random early detection (RED)
A discard mechanism that inhibits the packet synchronization tendencies of IP
traffic.
RCOS
See routing class of service (RCOS) (page 116).
RCC
See PNNI routing control channel (page 102).
RCL
See reduced cell loss mechanism (RCL) (page 111).