3Com 3C13636 Configuration Manual page 1314

3Com Router 3000 Ethernet Family
Configuration Guide
Type
WFQ
CBQ
Queue
Advantages
No.
Easily configured
Capable
bandwidth-occupying for data
sources (e.g. TCP packets
sending) used for interactive
purpose
Capable of reducing jitter
Capable of reducing the delay
Configur
for interactive application with
able
small data
Capable of assigning different
bandwidth for traffics with
different priorities
When the amount of the
traffics decreased, it can
automatically increase the
bandwidth for existing traffics.
Capable of classifying data
according to flexible, various
rules,
queue
mechanism for the expedited
forwarding
forwarding
best-effort (BE) services.
Capable of providing highly
precise bandwidth assurance
for the
ensuring
dispatching
according to a certain weight
Configur
proportion among various AF
able
services.
(0 to 64)
Capable
absolutely preferential queue
dispatching for the EF service
so as to ensure the real-time
data delay. In the mean time,
it can
disadvantage that the PQ of
low preference will "extinct
due to too little data flow"
since it restricts the data flow
of high preference.
Capable of providing WFQ
dispatching for the default
data of best-effort forwarding.
3Com Corporation
Chapter 3 Congestion Management
of ensuring the
providing different
dispatching
(EF), assured
(AF) and
AF service and
that the queue
is performed
of providing
overcome the
3-8
Disadvantages
The system overhead is
greater than that of FIFO
but smaller than that of PQ
and CQ
The system overhead is
large.