Brocade Multi-Service IronWare QoS and Traffic Management Configuration Guide (Supporting R05.6.00) - Manual (Page 68)

54 Multi-Service IronWare QoS and Traffic Management Configuration Guide
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Displaying QoS information
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Displaying QoS information
You can display the following QoS information as described:
• QoS Configuration Information – Using the show qos-map decode-map and show qos-map
encode-map commands, you can display the priority and drop-precedence values mapped
between values internal to the device and values that are received at the device or marked on
packets leaving the device. This is described in
“Displaying QoS Configuration information” on
page 54.
• QoS Packet and Byte Statistics – Using the show qos-map decode-map and show qos-map
encode-map commands, you can enable and display the contents of the QoS Packet and Byte
Counters as described in
“Clearing the QoS packet and byte counters” on page 54.
Displaying QoS Configuration information
You can display the following QoS Configuration information:
• QoS Decode Policy Map Configurations
• QoS Policy Map Binding Configurations
Clearing the QoS packet and byte counters
You can clear the QoS counters whose display is generated using the show np statistics command
as shown in the following.
Syntax: clear np statistics
Scheduling traffic for forwarding
If the traffic being processed by a Brocade device is within the capacity of the device, all traffic is
forwarded as received. Once we reach the point where the device is bandwidth constrained, it
becomes subject to traffic scheduling as described in this section.
The Brocade devices classify packets into one of eight internal priorities. Traffic scheduling allows
you to selectively forward traffic according to the forwarding queue that is mapped to according to
one of the following schemes:
• Strict priority-based scheduling – This scheme guarantees that higher-priority traffic is always
serviced before lower priority traffic. The disadvantage of strict priority-based scheduling is
that lower-priority traffic can be starved of any access.
• WRR (Weighted Round Robin) – With WRR destination-based scheduling enabled, some
weight-based bandwidth is allocated to all queues. With this scheme, the configured weight
distribution is guaranteed across all traffic leaving an egress port and an input port is
guaranteed allocation in relationship to the configured weight distribution.
• Mixed strict priority and weight-based scheduling – This scheme provides a mixture of strict
priority for the three highest priority queues and WRR for the remaining priority queues.