This attribute indicates the committed information rate (CIR) in bits
per second (bit/s). When rateEnforcement is set to on, cir is the rate
at which the network agrees to transfer information under normal
conditions. This rate is measured over a measurement interval (t)
that is determined internally based on CIR and the committed burst
size (Bc). An exception to this occurs when CIR is provisioned to
be zero, in which case the measurement interval (t) must be
provisioned explicitly.
This attribute should be ignored when rateEnforcement is off.