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Definition: CIR

(Committed Information Rate) In a frame relay network, the average transmission rate in bits per second (typically Kbps) for a virtual circuit. It defines the maximum rate that the network can handle under normal conditions. The CIR rate plus excess burst rate (Excess Information Rate, EIR) is either equal to or less than the speed of the access port into the network. Frame relay carriers define and package CIRs differently, and CIRs are adjusted with experience. See UNI, DLCI and frame relay.