rewrite_calling_station_id {
        if (Calling-Station-Id =~ /([0-9a-f]{2})[-:]?([0-9a-f]{2})[-:]?([0-9a-f]{2})[-:]?([0-9a-f]{2})[-:]?([0-9a-f]{2})[-:]?([0-9a-f]{2})/i){
                update request {
                        Calling-Station-Id := "%{1}:%{2}:%{3}:%{4}:%{5}:%{6}"
                }
        }
        else {
                noop
        }
}
