Access-point correlation for fast client transitions
During operation, an access point may receive, from an electronic device, a roaming request, where the electronic device is currently associated with a second access point. In response, the access point may broadcast a message in a network, which includes the access point and the second access point. Note that the message may include an L2 look-up message. In some embodiments, the message is only conveyed to the second access point via a router or a switch in the network. Then, the access point may receive, from the second access point, PMK information, where the second access point is included in a subset in the network with the access point. Next, based at least in part on the PMK information, the access point may generate a PMK for use during secure communication with the electronic device and may perform a fast BSS transition with the electronic device.
1 . An access point, comprising:
one or more interface circuits configured to communicate with a second access point and an electronic device, wherein the one or more interface circuits are configured to:
receive, from the electronic device, a roaming request, wherein the electronic device is currently associated with the second access point;
broadcast, in response to the roaming request, a message comprising a Layer 2 (L2) look-up message in a network that comprises the access point and the second access point;
receive, from the second access point, pairwise master key (PMK) information in response to the L2 look-up message, wherein the PMK information is received via a Layer 3 (L3) connection, wherein the access point and the second access point are included in an L2 subnet of the network; and
generate, based at least in part on the PMK information, a PMK for use during secure communication with the electronic device and perform a fast basic service set (BSS) transition with the electronic device,
wherein the L2 look-up message is a broadcast frame transmitted within the L2 subnet to identify which access point in the L2 subnet is currently associated with the electronic device and holds the PMK information for the electronic device.
2 . The access point of claim 1 , wherein the message is only conveyed to the second access point.
3 . The access point of claim 1 , wherein, before receiving the PMK information, the one or more interface circuits are configured to establish access point-to-access point communication with the second access point.
4 . The access point of claim 1 , wherein the one or more interface circuits are configured to receive, from the second access point and along with the PMK information, policy information of the electronic device, session information of the electronic device, or both.
5 . The access point of claim 4 , wherein the one or more interface circuits are configured to generate the PMK based at least in part on the policy information, the session information, or both.
6 . The access point of claim 1 , wherein the one or more interface circuits are configured to perform the fast BSS transition without involving a controller of the access point or the second access point.
7 . The access point of claim 1 , wherein the PMK information comprises a secondary PMK of the electronic device.
8 . The access point of claim 7 , wherein the secondary PMK comprises an R1 key holder (R1KH).
9 . The access point of claim 7 , wherein the secondary PMK is compatible with Institute of Electrical and Electronics Engineers (IEEE) 802.11r.
10 . The access point of claim 1 , wherein performing the fast BSS transition comprises:
receiving, from the electronic device, an association request; and
providing, to the electronic device, an association response.
11 . The access point of claim 1 , wherein, after associating with the electronic device, the one or more interface circuits are configured to provide, to a controller of the access point, an update to session information of the electronic device.
12 . The access point of claim 1 , wherein the one or more interface circuits are configured to provide a second message in the network.
13 . The access point of claim 12 , wherein the second message comprises a Layer 3 (L3) lookup message, and
wherein the L3 lookup message is provided to a second subnet in the network that does not include the access point and the second access point.
14 . A method for performing a fast basic service set (BSS) transition, comprising:
by an access point performing operations comprising:
receiving, from an electronic device, a roaming request, wherein the electronic device is currently associated with a second access point;
broadcasting, in response to the roaming request, a message comprising a Layer 2 (L2) look-up message in a network that comprises the access point and the second access point;
receiving, from the second access point, pairwise master key (PMK) information in response to the L2 look-up message, wherein the PMK information is received via a Layer 3 (L3) connection, wherein the access point and the second access point are included in an L2 subnet of the network; and
generating, based at least in part on the PMK information, a PMK for use during secure communication with the electronic device and performing the fast BSS transition with the electronic device,
wherein the L2 look-up message is a broadcast frame transmitted within the L2 subnet to identify which access point in the L2 subnet is currently associated with the electronic device and holds the PMK information for the electronic device.
15 . The method of claim 14 , wherein the fast BSS transition is performed without involving a controller of the access point or the second access point.
16 . A method for performing a fast basic service set (BSS) transition by a first access point in a network, the method comprising:
receiving, from an electronic device, a roaming request, wherein the electronic device is currently associated with a second access point, and wherein the first access point and the second access point are in an L2 subnet of the network;
broadcasting, in response to the roaming request, a message comprising a Layer 2 (L2) look-up message only to the second access point and a router that are in the L2 subnet of the network;
receiving, from the second access point, pairwise master key (PMK) information in response to the L2 look-up message, wherein the PMK information is received via a Layer 3 (L3) connection; and
generating, based at least in part on the PMK information, a PMK for use during secure communication with the electronic device and performing the fast BSS transition with the electronic device,
wherein the L2 look-up message is a broadcast frame transmitted within the L2 subnet to identify which access point in the L2 subnet is currently associated with the electronic device and holds the PMK information for the electronic device.
17 . The method of claim 16 , wherein the fast BSS transition is performed without involving a controller associated with the first access point or the second access point.