Configuration Guide User guide

586 FastIron Configuration Guide
53-1002494-02
Dynamic buffer allocation for QoS priorities for FastIron X Series devices
To set the total transmit queue depth limit on a port, enter a command such as the following.
Brocade(config)#qd 2 2049
This command sets the queue depth limit on port 2 to 2049. Packets are added to the port's
outbound queue as long as the packets do not cause the port to exceed 2048 buffers. If the port
reaches its queue depth limit of 2049, any new packets attempting to enter the port transmit
queue will be dropped until at least one buffer is freed.
Syntax: qd <port> <limit>
Specify the port variable in one of the following formats:
• FSX, FSX 800, and FSX 1600 chassis devices – slotnum/portnum
• FESX compact switches – portnum
The <limit> variable can be a value from 0 through 4095. Table 104 on page 585 lists the default
values.
Configuring the transmit queue depth limit for
a given traffic class on FastIron X Series devices
NOTE
To configure transmit queue depth limits for an SX-FI48GPP module, refer to “Buffer profile
configuration” on page 587.
To set the transmit queue depth limit on a port for a given traffic class, first enter the transmit
queue depth limit for the traffic class, and then specify the traffic class.
Brocade(config)#qd 2 200 7
This command sets the queue depth limit on port 2 to 200 for packets with a traffic class of 7.
Packets with priority 7 are added to the outbound queue on port 2 as long as the packets do not
exceed 199 buffers. When the port reaches its queue depth limit of 200, packets with the given
traffic class will be dropped.
Syntax: qd <port> <limit> <traffic-class>
Specify the port variable in one of the following formats:
• FSX, FSX 800, and FSX 1600 chassis devices – slotnum/portnum
• FESX compact switches – portnum
The <limit> variable can be a value from 0 through 4095 and cannot exceed the total transmit
queue depth limit configured for the port. Table 104 on page 585 lists the default values.
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.