The bottom line is that passive scanning in systems can expose a lot of information about all aspects of the system in normal communications without intruding upon operations. Active scanning has the potential to discover more information, and when combined with passive scanning, it gives a more complete picture.
Brick sizes vary depending on the country, the manufacturer and the purpose for which they are intended. In the United States, standard modern bricks are usually about 8 Ã 4 Ã 2.25 inches (203 Ã 102 Ã 57 mm). modular bricks are 7 5/8 long x 3 5/8 thick x3 5/8 deep.
The shape of the bricks also tends to vary, and thickness accounts for more of the size difference than length or width. The thickness of the bricks I measured ranged from 42mm to 90mm, a ratio of 2.1 between thickest and thinnest. The thickness of a standard modern brick is 65Â±3mm (ie 62-68mm).