private void doClean(timerEvent ev) {
    // Cleaner event
    if (VERBOSE) System.err.println("-- Cleaning up packetTable");

    // Might cause some recent packets to be dropped
    packetTable.clear();

    if (VERBOSE) {
      Runtime r = Runtime.getRuntime();
      System.err.println(
          "TOTAL: " + r.totalMemory() / 1024 + "KB FREE: " + r.freeMemory() / 1024 + "KB");
    }

    // Reregister timer event
    timer.registerEvent(CLEAN_TIMER_FREQUENCY, ev, mySink);
  }