24-6 User Guide for the Avaya P580 and P882 Multiservice Switches, v6.1
Chapter 24
High Priority
Allocation Displays the percent of the buffer’s queuing space allotted to
high priority traffic. Because the high-priority queue is
serviced more frequently than the normal priority queue,
raising this value may not necessarily provide better service.
In fact, if you are using the high-priority queue for delay-
sensitive traffic, you may want to reduce the amount of
memory devoted to the high-priority queue. This ensures that
packets that cannot be delivered in a timely manner are
discarded. If you want the high priority queue to guarantee
delivery of as many packets as possible, regardless of delay,
increase this value. The change does not take effect until you
reset the switch.
Priority
Threshold Allows you to set this parameter to the value at which the
switch starts sending packets to the high-priority queue. The
default value (4) causes all traffic with a priority greater than
or equal to 4 (4, 5, 6, and 7) to be assigned to the high-
priority queue. Priority schemes have more than two queues
(the IEEE allows up to 8, numbered 0 through 7). Avaya
recommends that you do not change this parameter.
High Priority
Service Ratio Allows you to set how many times the high priority queue is
serviced for each time the low priority queue is serviced. The
ideal value changes from queue to queue, but the goal is to
ensure that traffic mix guarantees optimal mix between high-
priority and best effort traffic.
High and
Normal
Overflow Drops
Displays the number of packets dropped because the
associated buffer is full. Indicates that the device
immediately before the queue is processing traffic faster than
the next downstream element can process the same volume
of traffic. For example, overflow drops on the input buffer
indicate that traffic is arriving faster than the switch matrix
can process it. Overflow drops on the output buffers
indicates that the output port cannot handle the volume of the
load being offered.
High and
Normal Stale
Drops
Displays the number of packets dropped because they timed
out waiting for service (using the age timer value). In the
high-priority queue, this can help determine how efficiently
the switch is processing “better never than late” traffic.
Excessive stale drops on the high-priority queue may
indicate the need to increase the service ratio on the high-
priority queue.
Congestion
Drops Displays the number of packets dropped because the switch
controller has sensed congestion at the outbound port.
Table 24-2. Buffer Detail Configuration Web Page ParametersParameter Definition...
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