Sams Teach Yourself TCP/IP in 24 Hours, Third Edition

Q&A

Q1:	Why does a mobile device associate (register) with an access point?
A1:	Incoming frames from the conventional network are relayed to the mobile device by the access point to which the device is associated. By associating with an access point, the device tells the network that the access point should receive any frames addressed to the device.
Q2:	Why does an 802.11 frame sometimes require four addresses?
A2:	The access point acts as a bridge, forwarding messages between the conventional Ethernet and the 802.11 wireless network. Devices on the conventional network must know the address of the access point (the receiver) that will forward the message to the wireless recipient. In bridging situations, it is also sometimes necessary to specify ...