8.5, Cisco Mobility Express will add support for Passpoint on WLANs. Access
Points which supports IEEE 802.11u-based network information and phone client
devices that are certified for WiFi Alliance's are able to work together to
support the Passpoint functionality.
enabled phone client devices discover and select target AP based on the
information gathered during the pre-association stage from an 802.11u-enabled
AP/Cisco Mobility Express controller. A phone client device has pre-provisioned
network information such as home OI Information, realm name and domain name,
presented as configuration file inside the phone client device. In addition,
the phone client device may obtain home network information using the IMSI data
derived from the inserted SIM/USIM card.
The 802.11u AP
provides various information listings that provide the HotSpot owner details,
roaming partners, realm list, 3GPP cellular information, and domain name. The
realm list also provides listings of the realm name and its associated EAP
authentication type mappings. Knowing this information is essential for the
phone client device so that correct EAP credential exchange may take place.
Through the WLAN
configuration, single SSID and multiple SSID will be configured with necessary
Passpoint information. This additional Passpoint information will be added on
beacon or probe response information, so that Passpoint-enabled phone client
device can detect and query AP to get further information. During the query
process, standard protocol format called ANQP-Access Network Query Protocol-is
followed. Here, the protocol describes the standard 2-way or 4-way handshake
process to get enough information from the AP and ANQP server to determine the
best AP that the phone client device can authenticate and associate with. This
handshake process is called GAS-Generic Advertisement Service-protocol that is
defined on IEEE 802.11u standard.
Passpoint, follow the procedure below: