Planet Technology Planet Intelligent Gigabit Ethernet Stackable/Routing Switch WGSW-2402A - Manual (Page 159)

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P2 6.25% e-mail Web research
P1 6.25%
P0 (Lowest) 6.25%
Casual web browsing
Total 100%
Note:
Low Drop Subclass - If class is oversubscribed, these packets are the last to be dropped.
High Drop Subclass - If class is oversubscribed, these packets are the first to be dropped.
T ABLE 5- 3 M EGABIT P ORT Q O S C LASS
Sample Application Class of
Megabit Port
Bandwidth Partitions
(Default and User
Configurable)
Low Drop Subclass High Drop Subclass
P3 (Highest) 75% Control information,
phone calls, circuit
emulation
Training video,
other multimedia
P2 12.5% Interactive activities
Web business
Non-critical
interactive activities
P1 6.25% E-mail, file backups
P0 6.25% Casual web browsing
Total 100%
In the Switch, it is possible that a class of traffic may attempt to monopolize system resources by
sending data at a rate in excess of the bandwidth partitions for that class. A well-behaved class offers
traffic at a rate no greater than the agreed-upon rate. By contrast, a misbehaving class offers traffic that
exceeds the agreed-upon rate. A misbehaving class is formed from an aggregation of misbehaving
microflows. To achieve high link utilization, a misbehaving class is allowed to use any idle bandwidth.
However, the quality of service (QoS) received by well-behaved classes must never suffer.
As above table illustrates, each traffic class may have its own distinct properties and applications. As
shown, classes may receive bandwidth assurances or latency bounds. In the example, P7, the highest
transmission class, requires that all frames be transmitted within 0.2 ms, and receives 30% of the 1
Gbps of bandwidth at that port.
Best-effort (P1-P0) traffic forms a lower tier of service that only receives bandwidth when none of the
other classes have any traffic to offer.
In addition, each transmission class has two subclasses, high-drop and low-drop. Well-behaved users
should not lose packets. But poorly behaved users - users who send data at too high a rate - will