Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide - Manual (Page 48)

For ports that use buffer profile 2, packets with priority 1 are added to the outbound queue as long
as the packets do not exceed 299 buffers. When the port reaches its queue depth limit of 300,
packets with the given traffic class will be dropped.
Syntax: [no] qd slotnum/portnum limit traffic-class
The limit variable can be a value from 0 through 4095 and cannot exceed the total transmit queue
depth limit configured in the previous step.
The sum of the queue depth limits for individual traffic classes on a port does not need to equal the
total queue depth limit for the port:
• If the sum of the individual traffic class queue depth limits exceeds the total port limit and the total
port limit is reached, any buffer that gets released can be used by any traffic class queue that
has not reached its individual limit.
• If the sum of the individual traffic class queue depth limits is less than the total port limit, the
remaining buffers can be used only by packets with a priority of 7.
The traffic-class variable can be a value from 0 through 7, where 7 is the highest priority queue.
4. Enter the write memory command to save the configuration.
Displaying the buffer profile configuration
To display the buffer profile configuration for an SX-FI48GPP Interface module, use the show
configuration command.
The following example shows that buffer profile 2 and its configured queue depth values apply to ports
1/1 and 1/2. Although the profile configuration was changed for port 1/1 only, port 1/2 has also
changed to match the configuration.
device(config)#show configuration
qd 1/1 profile-id 2
qd 1/2 profile-id 2
!
qd 1/1 1000
qd 1/2 1000
qd 1/1 300 1
qd 1/2 300 1
Syntax: show configuration
Default queue depth limits for FastIron X Series devices
Table 7 on page 45 defines the default maximum queue depth values per port, per traffic class. The
Brocade device drops the packets that cause the port to exceed these limits.
NOTE
The SX-FI48GPP Interface module supports 48 tri-speed (10/100/1000) ports. When the ports are
configured at lower speeds, for example 100 Mbps or 10 Mbps, the maximum queue depth is less than
256 when egress congestion occurs at the front-end Network Processor (NP) of the SX-FI48GPP
module. If egress congestion occurs at the back-end NP of the SX-FI48GPP module, the maximum
queue depth is 4095. The limit for buffer sharing is 4088.
Displaying the buffer profile configuration
48 FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide
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