The elements of this backbone are core switches fulfilling OSI layer 2 commuting with 100BASE-TX or 100BASE-FX connections in local room and or 1000BASE-LC connections for inter-station connections.

• 该骨干结构的元件是核心开关，实现OSI层2同本地室内100BASE-TX或100BASE-FX连接线的数据交换和/或同站间联络线1000BASE-LC连接线的数据交换。