This is starting to come up and be a problem as we actually get to using these ...  The usable internal depth is 14" and since the cabinet is passively cooled, any transport gear must be certified for 50 ° C.  This means the the existing Brocade switches wont fit or operate ... the coming 6910 will. Also from the PtP side, the Summit Extreme (their preferred switch) is also too big and not hardened. They have an update coming in the winter; the E4G-200.