[信息与通信]Aruba mobile-LAN solution-v3.ppt

* WLAN switching uses “thin APs” There is very little functionality included in the AP. An Aruba AP attaches to the network and an image is downloaded through TFTP to the AP. The AP does not permanently store the image. After receiving the image, the AP then builds a GRE tunnel back to the WLAN switch where the wireless intelligence is located. These functions can include authentication, encryption and other pieces described in other parts of the course. Because the functionality is located in the switch, upgrades do not require a change in the APs. Rather, it can occur in the switch. * This diagram shows how Aruba addresses these issues. Here we have a similar topology to the previous network of a traditional wireless network. This one is implemented with Aruba technology instead of the traditional model. However there are key differences. Like the previous model, APs are attached to the wired network. But in this case they are thin APs that tunnel all of their traffic back to the Aruba mobility controller. The mobility controller is placed between the wireless and wired network and serves several purposes: To serve as the point for encryption and decryption for all wireless traffic To provide authentication and authorization, including firewall functionality To manage the thin APs These changes are fundamentally different from the previous model. Let’s explore these differences in more detail. Earlier we mentioned that, in a traditional model, once the wireless traffic is placed on the wired network the packets intermingle and the firewall cannot tell the difference between these packets – other than by IP address and MAC. As a matter of fact, the firewall does not even know which packets originated on the wireless network versus the wired network. This is not true in the Aruba model. By terminating wireless traffic on the mobility controller, we know exactly which traffic originated on the wireless traffic. No other traffic will be placed into th