TEID is an endpoint used to uniquely identify a tunnel. Corresponding to a UE or a UE session, which of the following entities are used? (Multiple choice)
A . Used for the S11 interface between the MME and the SGW
B . Used for S5/S8 interface between SGW and PGW
C . Used for S1U interface between the eNB and the SGW
D . Used for S1-MME interface between the eNB and the MME
Answer: ABC