Refer to the Exhibit.

Label A, B and C.

A.
A-Gigabit Uplink ports, B-Cube Switches, C-Root Switch

B.
A-Gigabit Uplink ports, B-Root Switches , C-Cube Switches

C.
A-Cube switch spare ports, B-Cube Switches, C-Root Switch

D.
A-Cube switch crossover ports, B-Cube Switches , C-Root Switches