"the LWAPP Control and Data messages are encapsulated in UDP packets that are carried over the IP network. The only requirement is established IP connectivity between the access points and the WLC. The LWAPP tunnel uses the access point's IP address and the WLC's AP Manager interface IP address as endpoints. The AP Manager interface is explained in further detail in the
implementation section. On the access point side, both LWAPP Control and Data messages use an ephemeral port that is derived from a hash of the access point MAC address as the UDP port. On the WLC side, LWAPP Data messages always use UDP port 12222. On the WLC side, LWAPP Control messages always use UDP port 12223.
The mechanics and sequencing of Layer 3 LWAPP are similar to Layer 2 LWAPP except that the packets are carried in UDP packets instead of being encapsulated in Ethernet frames."
Taken from "Cisco 440X Series Wireless LAN Controllers Deployment Guide"