Disclosed is an apparatus and method for simulating a plurality of cable modems for testing a device, such as a head end complex. In general terms, the present invention provides a multiple cable modem simulator and techniques for setting up and executing the same. In one implementation, the multiple cable modems are simulated by simulating multiple MAC (media access control) state machines for multiple cable modems. In other embodiments, a simulator of the present invention includes a mechanism for simulating physical operating conditions of the simulated cable modems. For example, even when the simulator is located at a single test location, different distances and power levels may be simulated for the different simulated cable modems.