The excess information rate (EIR) is used to control the data rate of a virtual circuit when no network congestion exists. The EIR specifies the data rate (in bits per second) in excess of the Committed Information Rate (CIR) to which a virtual circuit can burst when no network congestion exists.
If the EIR is set to zero (disabled), a virtual circuit will burst up to the full access port data rate, when there is no network congestion. When network congestion exists, the virtual circuit data rate is throttled to the CIR. This is the default setting.
If the EIR is non-zero, the virtual circuit will burst up to CIR+EIR when there is no network congestion. When network congestion exists, the virtual circuit data rate is throttled to the CIR.