
13-23
Port Traffic Controls
Guaranteed Minimum Bandwidth (GMB)
Syntax:
[ no ] int <
port-list
> bandwidth-min output
[ <
queue1%
> <
queue2%
> <
queue3%
> <
queue4%
> <
queue5%
>
<
queue6
%> <queue7%> <queue8%>]
For ports in
<
port-list
>
, specifies the minimum outbound
bandwidth as a percent of the total bandwidth for each
outbound queue. The queues receive service in descending
order of priority. You must specify a bandwidth percent
value for all eight queues, and the sum of the bandwidth
percentages must not exceed 100%. (
0
is a value for a queue
percentage setting.) Configuring a total of less than 100%
across the eight queues results in unallocated bandwidth
that remains harmlessly unused unless a given queue
becomes oversubscribed. In this case, the unallocated
bandwidth is apportioned to oversubscribed queues in
descending order of priority. For example, if you configure
a minimum of 10% for queues 1 - 7, and 0% for queue 8,
then the unallocated bandwidth will be available to all eight
queues in the following prioritized order:
1. Queue 8 (high priority)
2. Queue 7 (high priority)
3. Queue 6 (medium priority)
4. Queue 5 (medium priority)
5. Queue 4 (normal priority)
6. Queue 3 (normal priority)
7. Queue 2 (low priority)
8. Queue 1 (low priority)
A setting of
0
(zero %) on a queue means that no bandwidth
minimum is specifically reserved for that queue for each
of the ports in
<
port-list
>
. Also, there is no benefit to setting
the high-priority queue (queue 8) to
0
(zero) unless you
want the medium queue (queue 4) to be able to support
traffic bursts above its guaranteed minimum.
(continued)
3500-5400-6200-8200-MCG-Jan08-K_13_01.book Page 23 Monday, January 28, 2008 10:04 AM