NGBE_B2BT
((36 * (NGBE_B2BT(_max_frame_link) + NGBE_PFC_D + \
2 * NGBE_B2BT(_max_frame_tc))
(2 * NGBE_B2BT(_max_frame_tc) + (36 * NGBE_PCI_DELAY / 25) + 1)