This paper considers a generic CSMA and CSMA/CD protocol that allows one to unify the nonpersistent and one-persistent protocols as special cases, and solve the characterization problem under the infinite population model. Explicit expressions of the interdeparture time moment generating function, as well as expressions for the channel throughput and the variance of output process, are obtained for both slotted and nonslotted cases. In addition to direct simulation results, we also provide a novel statistical analysis/simulation procedure for the purpose of validating the infinite population model and the analytical results. Both approaches indicate that the infinite population model is quite appropriate for analyzing this generic protocol.