3Com 4007, Command Reference Manual

Page: 549 / 574

549
Layer 2
Switching
Modules
✓
Multilayer
Switching
Modules
qos statistics transmit Displays QoS transmit statistics on a Multilayer Switching Module.
Valid Minimum Abbreviation
q s t
Important Considerations
■
The transmit statistics help you track bandwidth utilization and packet
loss by physical port and queue (
reserved
,
high
,
best
, and
low
).
■
The RSVP and network control packets go out on the reserved queue.
■
When you mark any packet (
conforming
or
excess
) as
loss
eligible
, the packet is dropped if the transmit queue for which it is
destined is over its threshold. A packet that is marked loss-eligible falls
into one of the two
highLoss
statistic categories:
■
If the transmit queue is not over its threshold, the packet is sent
and counted as a
highLossSent
packet.
■
If the transmit queue is over its threshold, it is dropped and
counted as a
highLossDropped
packet.
■
If you do not mark a packet as loss-eligible, it falls into one of the
three
lowLoss
statistics.
■
If the queue is not over the threshold, it is counted as a
lowLossSent
.
■
If the queue is over its threshold, it is counted as
lowLossDelayed
.
■
If the queue is full, it is counted as
lowLossDropped
.
■
Loss-eligible packets are conforming packets that are discarded
instead of queued when transmit queues back up beyond a threshold.
You can specify whether conforming packets (as well as
nonconforming excess packets) are loss-eligible when you define a
control. Marking packets loss-eligible is useful to enable intelligent
discard of traffic in a congestion situation. When the module is
congested, you can decide which traffic can be discarded and mark
that traffic as loss eligible.