Configuration Guide User guide

FastIron Configuration Guide 589
53-1002494-02
Dynamic buffer allocation for FCX, FWS, and ICX devices
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.
Syntax: show configuration
Default queue depth limits for FastIron X Series devices
Table 104 defines the default maximum queue depth values per port, per traffic class. The craig
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.
Dynamic buffer allocation for FCX, FWS, and ICX devices
By default, the IronStack architecture allocates fixed buffers on a per-priority queue, per-packet
processor basis. The buffers control the total number of packets that can be queued in the
outbound transmit for the port. In instances of heavy traffic bursts to aggregation links, such as in
stacking configurations or mixed-speed environments, momentary oversubscription of the buffers
and descriptors may occur. A descriptor points to one or more packet buffers.
Brocade FastIron stackable devices provide the capability to allocate additional egress buffering
and descriptors to handle momentary bursty traffic periods, especially when other priority queues
may not be in use, or may not be experiencing heavy traffic. This allows users to allocate and
fine-tune the depth of priority buffer queues for each packet processor.
Brocade(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