This read-create value holds the Excess Burst Size, in bits, for this traffic descriptor. Be is the additional above-CIR allowance a burst can use before it's eligible for outright discard rather than merely being marked as excess, making it effectively the last line of tolerance before traffic starts getting dropped for exceeding the contract. Setting Be to 0 on a PVC means any traffic beyond the committed burst is dropped immediately rather than being marked discard-eligible and forwarded whenever the network happens to have spare capacity.