When inbound or outbound traffic exceeds the bandwidth available for the defined CIR and CBS, it is dropped or made subject to the conditions set in the excess information rate (EIR) and excess burst size (EBS).
EIR and EBS accommodate traffic that exceeds the conditions of the committed information rate (CIR) and the committed burst size (CBS). EIR is the maximum sustained rate at which inbound and outbound traffic can exceed the CIR. Traffic that does not use all of its allotted EIR accumulates credit (bandwidth) up to the amount defined by the EBS. This accumulated bandwidth can be used to accommodate temporary bursts of traffic that exceeds the EIR. Inbound or outbound traffic that exceeds the amount of accumulated bandwidth is dropped.