An electronic device may be operable to communicate over a physical medium and to regulate the transmission of a message onto the physical medium. The device may access the medium in accordance with a CSMA scheme, wherein one or more values of one or more CSMA parameters may be determined based on the result of a comparison of a received search token to data stored in the communication device. The message may be a response to a received request message, and the search token may have been received in the request message. A value of the CSMA parameter(s) may be determined based on the result of a comparison of the score and one or more thresholds. The threshold(s) may have been received in the request message. The value(s) of the CSMA parameter(s) may be determined based on one or more initial values contained in the received request message.