A test packet generator (225a) within a physical layer device (230) may generate test packets to be communicated over a closed communication path established within the physical layer device (230). The test packets may include a pseudo-random bit sequence. A receiver within the physical layer device (230) may receive at least a portion of the generated test packet. A test packet checker (225b) within the physical layer device may compare at least a portion of the received test packets with at least a portion of the generated test packets in order to determine the bit error rate for the physical layer device. A window counter (225c) within the physical layer device (230) may count at least a portion of a number of bits received within the generated test packets and a number of bits that are in error in at least a portion of the number of bits received. Accordingly, the bit error rate may be calculated based on a ratio of the number of counted bits in error to the number bits counted in the at least a portion of the number of bits received.