Nortel Networks NN47250-500 WPA information element

370 Configuring user encryption
NN47250-500 (Version 03.01)
WPA information element
A WPA information element (IE) is a set of extra fields in a wireless frame that contain WPA information for the access
point or client. To enable WPA support in a service profile, you must enable the WPA IE. The following types of
wireless frames can contain a WPA IE:
• Beacon (sent by an AP)—The WPA IE in a beacon frame advertises the cipher suites and authentication methods
that an AP radio supports for the encrypted SSID. The WPA IE also lists the cipher suites that the radio uses to
encrypt broadcast and multicast frames. An AP radio always uses the least secure of the cipher suites to encrypt
broadcast and multicast frames to ensure that all clients associated with the SSID can decrypt the frames. An AP
radio uses the most secure cipher suite supported by both the radio and a client to encrypt unicast traffic to that
client.
• Probe response (sent by an AP radio)—The WPA IE in a probe response frame lists the same WPA information that
is contained in the beacon frame.
• Association request or reassociation (sent by a client)—The WPA IE in an association request lists the
authentication method and cipher suite the client wants to use.