Convert Annnex A to B or Annex B to A You can convert you Annex B router to make it work on an Annex A line, or the opposite from A to B. This method has been tested by some users and most of the time it works. In order to make the conversion, you need to flash the router with a special firmware, with the header of the original firmware, but with the ADSL drivers of the right Annex version. To return back to the original state, simply flash the router in “recovery” mode, or, if u have flashed the AnnexA to B firmware, then flash the AnnexB to A.