Since pc can be easily connected to the network and get all kinds of internal information , there exists information security hidden troubles in the system . aas can establish a hierarchical communication safeguard to enforce the strict authentication on those who want to connect into the network . this action insures that only those expected users will be connected into the network and avoid the illegal entry 針對個人計算機可以很方便的接入網絡而獲取各種內部資源的信息安全隱患, aas接入認證服務器可以構筑一種分層次通信保護結構,對試圖接入網絡的用戶進行嚴格的認證,保證只有系統期望的用戶才能接入網絡,避免非法用戶的侵入。