Specifications

Guidelines for Configuring QoS
ExtremeWare XOS 11.0 Concepts Guide 121
Displayed information includes:
• QoS profile name
• Minimum bandwidth
• Maximum bandwidth
• Priority
• Additionally, egress QoS information can be displayed from the traffic grouping perspective by
using the command, which displays the QoS profile assignments to the port:
show ports
{<port_list>} information {detail}
.
Guidelines for Configuring QoS
The following are useful guidelines for configuring QoS:
• If you are using DiffServ for QoS parameters, Extreme Networks recommends that you also
configure 802.1p or port-based QoS parameters to ensure that high-priority traffic is not dropped
prior to reaching the Master Switch Module (MSM).
• The command to replace the 802.1p or DiffServ value affects only those traffic groupings based on
explicit packet class of service and physical/logical groupings.
Bi-Directional Rate Shaping
With software version 11.0, you can configure and display bi-directional rate shaping parameters.
Bi-directional rate shaping allows you to manage bandwidth on Layer 2 and Layer 3 traffic flowing to
each port on the switch and from there to the backplane. You can configure up to eight ingress queues,
which send traffic to the backplane, per physical port on the I/O module. By defining minimum and
maximum bandwidth for each queue, you define committed and peak information rates for each queue.
You can define different priorities for each queue for each port. Rate shaping on the ingress port allows
the switch to enforce how much traffic from a particular port can ingress to the system.
Bi-directional rate shaping controls the traffic from the ingress ports to the backplane and provides
guaranteed minimum rates. The number of queues from the ingress port to the backplane differs
between I/O modules. The 1 Gbps I/O module has 2 queues from the ingress port to the backplane,
and the 10 Gbps I/O module has 8 queues from the ingress port to the backplane.
You set minimum bandwidth, maximum bandwidth, and priority for each queue for each port. Use
prioritization when two or more hardware queues on the same physical port are contending for
transmission, only after their respective bandwidth management parameters have been satisfied. Once
the priorities are satisfied, the switch uses a round-robin system to empty the queues to the backplane.
Table 23 displays the mapping of the ingress queues and the priority value for each I/O module.
Table 23: Ingress queue mapping for I/O modules
I/O module Ingress queues Priority value
1 Gbps module IQP1 1 to 4
IQP2 5 to 8