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List of terms

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).

Nortel Multiservice Switch 7400/15000/20000

Terminology

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Copyright © 2006, Nortel

Nortel Confidential

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Panasonic 15000 manual Raig, Rcos, Rcc, Rcl