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DTUS065 rev A.7 – June 27, 2014
V.5.3
Pre-shared key mode (PSK)
In Pre-Shared Key mode (PSK, also known as personal mode), each Access
Point client must provide a password to access the network. The password
may be from 8 to 63 printable ASCII characters. Most operating systems
allow the password to be stored to avoid re-typing. The password must also
remain stored in the Wi-Fi access point.
All Wi-Fi devices on your Wi-Fi cell must have the same Pre-Shared Key.
V.5.4
Enterprise mode (802.1x, RADIUS)
WPA/WPA2-Enterprise, or 802.1x, provides authentication to devices trying
to attach to a private network through a boundary Access Point, establishing
the access point as the gateway to LAN resources, or preventing access from
that device if authentication fails.
NOTE: since in a chain of repeaters the farthest ones would depend
on the nearest ones to access the 802.1X server, this security is not
available in repeater mode. WPA/WPA2-PSK can still be used.
The authentication process is organized around several agents:
-
User, also called supplicant or Wireless Node (WN),
-
Wireless access point or authenticator,
-
Authentication server, most often a RADIUS (Remote Authentication
Dial-In User Service) server,
-
Authentication modus operandi.
When a wireless node (WN) requests access to a LAN resource, the first step
is the physical association between the client and the access point, defining a
so-called “access port” (number 1 on the diagram).
The access point (AP) asks for the WN's identity. Then it establishes a point-
to-point EAP tunnel between the WN and the authentication server (number
2 on the diagram).
No other traffic other than EAP is allowed until the WN is
authenticated (the
“port”
is closed).
Until authenticated the client cannot
access the LAN.
Once the authentication server informs the authenticator that the WN is
authenticated, the traffic to the LAN is allowed (number 3 on the diagram):
the “port” is open. Otherwise the “port” stays closed.
Note: 802.1x also offers a system to exchange keys which will be used to
encrypt communications and to check integrity.
