Brocade FastIron Ethernet Switch Traffic Management Guide - Manual (Page 52)

Rate shaping overview
Outbound Rate Shaping is a port- level feature that is used to shape the rate and control the
bandwidth of outbound traffic on a port. This feature smooths out excess and bursty traffic to the
configured maximum limit before it is sent out on a port. Packets are stored in available buffers and
then forwarded at a rate no greater than the configured limit. This process provides for better control
over the inbound traffic of neighboring devices.
The device has one global rate shaper for a port and one rate shaper for each port priority queue.
Rate shaping is done on a single-token basis, where each token is defined to be 1 byte (1 packet for
ICX 6650).
Configuration notes for rate shaping
The following rules apply when configuring outbound rate shapers:
• Outbound rate shapers can be configured only on physical ports, not on virtual or loopback ports.
• When outbound rate shaping is enabled on a port on an IPv4 device, the port QoS queuing
method (qos mechanism ) will be strict mode. This applies to IPv4 devices only. On IPv6 devices,
the QoS mechanism is whatever method is configured on the port, even when outbound rate
shaping is enabled.
• You can configure a rate shaper for a port and for the individual priority queues of that port.
However, if a port rate shaper is configured, that value overrides the rate shaper value of a priority
queue if the priority queue rate shaper is greater than the rate shaper for the port. .
• You can configure rate shaping on individual ports of the LAG. You cannot configure rate shaping
on the LAG itself.
• You can enable rate shaping on the individual ports for static and dynamic LAG. You cannot
enable rate shaping on other types of LAG (for example, keep-alive).
• For configuring rate shaping on ICX7750 devices, you must reset the default switching
methodology from cut-through to store-and-forward mode. To change the default setting, use
store-and-forward command.
• For configuring rate shaping on dynamic LAG for ICX 7750 devices, be sure to configure the
queues where LACP packets are not forwarded. If you configure rate shaping on dynamic link
aggregation group (LAG) ports (either on the port or on the queue), it can drop LACP packets and
cause a dynamic LAG failure
For more information on LAG configuration, refer to the FastIron Ethernet Switch Layer 3 Routing
Configuration Guide.
The configured rate shaper values are rounded up to the nearest multiples of minimum values
supported on the platform. The following table shows the minimum and maximum values for output
rate shaping on various devices. Values are in Kbps for all the platforms except those for ICX 6650
devices, which are in pkts/s.
Output rate shaping on FastIron devices TABLE 29
Device Module Minimum Maximum
ICX 6610 1 Gbps ports 3 999750
ICX 6610 10 Gbps ports 3388 9996513
ICX 6430 All 55 890232
Rate shaping overview
50 FastIron Ethernet Switch Traffic Management Guide
53-1003093-03