Specifications

Bi-Directional Rate Shaping
ExtremeWare XOS 11.0 Concepts Guide 123
Please note that these maximum committed rates vary with the number of active ports on each I/O
module. The rates shown in Table 24 are what you can expect when you all running all ports at traffic
level. If you are using fewer ports, you will have higher committed rates available for each port. And,
the maximum committed rate is reached when you are running traffic on only one port.
NOTE
Keep the sum of the minimum bandwidth values for the applied ingress queues less than 90%. If the
sum exceeds 90%, a lower priority queue might be unable to transmit in a sustained over-subscription
situation.
If you choose a setting not listed in the tables, the setting is rounded up to the next value. If the actual
bandwidth used is below the minimum bandwidth, the additional bandwidth is not available for other
queues on that physical port.
Configuring Bi-Directional Rate Shaping
The maximum bandwidth or rate defined in the ingress QoS profile defines the rate limit for ingress
traffic on rate-shaped ports. You set minimum and maximum rates for each port on the ingress port,
using either percentage of total bandwidth or absolute values for committed and peak rates in Kbps or
Mbps. You also set the priority level for each queue.
To define rate shaping on a port, you assign a minimum and maximum bandwidth or rate plus a
priority value to each queue on the ingress port (see Table 23 for the number of queues available to each
port on the I/O module). Use the following command to define rate shaping:
configure qosprofile ingress <iqp> [minbw <percentage> maxbw <percent> |
committed_rate <bps> [k | m] peak_rate <bps> [k | m]] priority <level> ports
[<port_list> | all]
If you choose to use committed rate and peak rate values, be aware of the interactions between the
values and the command line interface (CLI) management system. You can enter any integer from 0 in
the CLI; however, functionally the switch operates only in multiples of 62.5 Kbps. Also note that the CLI
system does not accept decimals.
Rate shaping is disabled by default on all ports; the system does use existing 802.1p, port, and VLAN
values to assign packets to the ingress queue. The rate shaping function is used to assign specific
priorities by absolute rates or percentages of the bandwidth.
To enable this rate shaping feature, use the configuration command. To disable the rate shaping, use the
following command:
unconfigure qosprofile ingress ports all
To display the parameters for rate shaping (the values for the IQPs), use the following commands:
show qosprofile {ingress | egress} ports [ all | <port_list>]
show ports {<port_list>} information {detail}
Additionally, you can monitor the performance by using the following command:
show ports <port_list> qosmonitor {ingress | egress}