[bardd]

It's not, the bumper surrounds the frame perimeter.

Edit:

R03
The ROBOT must satisfy the following size constraints:

* total length of the FRAME PERIMETER sides may not exceed 112 in. (see Figure 4-1 for examples),
* PLAYING CONFIGURATION horizontal dimensions may never exceed a 54 in. diameter cylinder (see G23 and G23-1), and
* height may never exceed 84 in. tall.

R22
ROBOTS are required to use BUMPERS to protect all outside corners of the FRAME PERIMETER. For adequate protection, at least 8 in. of BUMPER must be placed on each side of each outside corner (see Figure 4-2).

The bumpers cover the frame perimeter and are not part of it.