Rate shaping configuration notes

Rate shaping smooths 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 following apply when configuring outbound rate shaping:

• Outbound rate shaping can be configured only on physical ports, not on virtual or loopback ports.
• RUCKUS ICX devices have 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.
• 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 link aggregation group (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 any other type of LAG (for example, keepalive).
• RUCKUS ICX devices do not support port-based rate shaping for PE ports.
• You cannot configure rate shaping on devices where the packet-forwarding method is cut-through (except ICX 7850). On ICX 7750 devices, the default packet-forwarding method is cut-through so you must first configure the store-and-forward command to change the method to store-and-forward. On ICX 7450 devices, store-and-forward is the default method.
  Note: You must save the configuration and reload for the change to take effect. Refer to the description of the store-and-forward command for more information.
• When configuring rate shaping on dynamic LAGs for ICX 7750 devices, you should configure the queues where the Link Aggregation Control Protocol (LACP) packets are not forwarded. If you configure rate shaping on dynamic LAG ports (either on the port or on the queue), LACP packets can be dropped and cause a dynamic LAG failure.

For more information on LAG configuration, refer to the RUCKUS FastIron Layer 3 Routing Configuration Guide.

The configured rate shaping 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 kilobits per second (Kbps) for all the platforms.