The most mature medium access control protocol for wireless local area networks is the IEEE 802.11 standard. The primary access mode of this protocol is based on the mechanism of carrier sense multiple access with binary exponential backoff. We develop a finite-source feedback queueing model for this access mode. In this model, we derive expressions for the throughput and the first moment of the delay and a set of equations to compute the Laplace Stieltjes Transform and higher moments of the delay. The accuracy of the model is verified by simulation.