Specifications

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percent full, a non-PLP packet is never dropped (it matches the stream profile,
but not the non-PLP profile), and a PLP packet is always dropped (it matches
both the stream and PLP set profiles and in the PLP profile has a 100-percent
drop probability).
Figure: RED Drop Profiles
To randomize the drop event, RED generates a random number for the packet in
the queue and plots this number to the Y axis of the drop profile graphs shown in
the figure above. If, at the stream's or queue's congestion level, the drop
probability is greater than the random number, the drop decision for the profile is
taken.
The stream, PLP, and non-PLP drop profiles apply to all the output transmission
queues on an FPC.
The queue fullness is the percentage of the total buffer assigned to an output
transmission queue. A queue that has only 20 percent of the total buffer becomes
full faster than one with 60 percent of the total buffer if an equal amount of traffic
is being placed in both queues.
The details about the complete Class of Service implementation can be found
hereinafter.
2.6.3 Setting congestion control variables
For all interface types except ATM and Gigabit Ethernet, you can configure leaky
bucket properties, which allow you to limit the amount of traffic received on and
transmitted by a particular interface. You effectively specify what percentage of
the interface's total capacity can be used to receive or transmit packets.
By default, leaky buckets are disabled and the interface can receive and transmit
packets at the maximum line rate.
To configure leaky bucket properties, include one or both of the receive-bucket
and transmit-bucket statements at the [edit interfaces interface-name] hierarchy
level:
[edit interfaces interface-name]
user@host# show
receive-bucket {
overflow (tag | discard);
rate percentage;
threshold number;
}
transmit-bucket {
overflow discard;
rate percentage;
threshold number;
}
In the rate option, specify the percentage of the interface line rate that is available
to receive or transmit packets. The percentage can be a value from 0 (which
means none of the interface line rate is available) to 100 (which means that the
maximum interface line rate is available). For example, when you set the line rate
to 33, the interface receives or transmits at one third of the maximum line rate.