Metering

Per-flow metering measures and controls the rate of packets for each flow entry. Per-flow meters enable OpenFlow to implement simple QoS operations, such as rate limiting, and can be combined with per-port queues to implement complex QoS frameworks, such as DiffServ.

Meters are attached directly to flow entries. Each meter can have one or more meter bands. Each meter band specifies the rate of the band and the way packets are processed (DROP or DIFFSERV). OpenFlow metering operation is similar to ingress rate limiting in a QoS operation.

A meter table consists of meter entries. The counters in the following table are available in the meter entry.

Meter Entry Counters

Counter Description
Meter Identifier A 32-bit unsigned integer uniquely identifying the meter.
Meter band A list of meter bands, where each meter band specifies the rate of the band and the way to process the packet. Rate and burst size are based on the line rate of the data traffic in contrast to the information rate.
Counter Number of packets processed by a meter.

Packets are processed by a single meter band based on the current measured meter rate. The meter applies the meter band with the highest configured rate that is lower than the current measured rate. If the current rate is lower than any specified meter band rate, no meter band is applied.

Supported Meter Bands

Meter Bands Supported by ICX
DROP Yes
DSCP_REMARK No
EXPERIMENTER No

Each band type contains the following meter configuration parameters from the controller:

  • Rate value in kbps
  • Rate value in packets per second
  • Burst size
  • Statistics collection

Meter Configuration Parameters

Configuration Flags Supported by ICX
OFPMF_KBPS Yes
OFPMF_PKTPS No
OFPMF_BURST Yes
OFPMF_STATS Yes

The metering system supports the features in the following table.

Metering Capabilities Supported for Metering Features

Feature On RUCKUS ICX Devices
Maximum meter available in the system 1024
Band types (bitmap) DROP
Capabilities (bitmap) KBPS, BURST, STATS
Maximum number of bands per meter 1
Maximum color value 2