16.1.4B User plane

23.4023GPPArchitecture enhancements for non-3GPP accessesRelease 18TS

16.1.4B.1 User plane for PDN connection

There is a one-to-one mapping between the PDN connection or WLCP bearer, if applicable, and the S2a tunnel, and there is a one-to-one mapping between the PDN connection or S2a bearer, if applicable, and the point-to-point link between UE and TWAG. When the PDN connection is established during the UE initiated WLCP procedure, the TWAG sends a MAC address, which is specific for the PDN connection, to UE to be used by the UE as the MAC address of the TWAG for user plane packets on the default bearer. When additional S2a bearers are created for a PDN connection, the TWAG sends, when applicable, a MAC address, which is specific for the S2a bearer. The TWAG maintains the mapping between the MAC address and the S2a bearer.

The UE also maintains the mapping between the PDN connection or WLCP bearer, if applicable, and the TWAG MAC address corresponding to the PDN connection or WLCP bearer, if applicable, received during the WLCP procedure.