Panasonic 15000 - Manual (Page 148)

- 148 -
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
VTDS
Voice transparent data service. See transparent data service (TDS)
(page 136) .
VUNI
See virtual interface (page 142) .
waiting delay
The time a frame or cell waits in a transmission queue before it gets
transmitted.
WAN
See wide area network (WAN) (page 148) .
warm standby
Warm standby applications reduce service outages during an FP or CP
switchover. During an equipment switchover, warm standby applications incur
a longer outage of service than hot standby applications, but not as long as
cold standby applications. As well, all connections must be reestablished.
WFQ
Weighted fair queuing. See weight limited FIFO algorithm (WLFA) (page 148) .
weight limited FIFO algorithm (WLFA)
A Nortel Multiservice Switch system proprietary implementation of weighted
fair queuing (WFQ), a non-shaping intra-class scheduler. WLFA is a
mechanism for deciding which cells arriving at a Multiservice Switch node
over individual circuits are delivered next to the common FIFO (first-in-first-
out) trunk queue. WLF works by giving more common queue space to circuits
that have a higher priority. The allocation of queue space effectively assures
higher priority cells a greater share of trunk bandwidth.
weighted random early detection (WRED)
A mechanism for discarding packets based on a weighted random decision
only after the node exceeds a minimum VC queue-length threshold. The node
determines weights according to the extent to which the queue-length
threshold is exceeded with respect to a defined maximum threshold. WRED
is a method for early congestion detection, useful to window-based protocols
(for example, TCP).
wide area network (WAN)
A network used for data communications among widely distributed
geographic sites (bigger than a MAN). Technologies used include leased
lines, connecting routers, multiplexers, packet switches, voice switches, and
products such as Nortel Multiservice Switch nodes.