The present document defines the stage-3 protocol description for several reference points for the non-3GPP access in EPS. The present document is applicable to: ? The SWa reference point between an un-trusted non-3GPP IP access and the 3GPP AAA Server/Proxy. ? The STa reference point between a trusted non-3GPP IP access and the 3GPP AAA Server/Proxy. ? The SWd reference point between the 3GPP AAA Proxy and 3GPP AAA Server. ? The SWx reference point between the 3GPP AAA Server and the HSS. ? The S6b reference point between the 3GPP AAA Server/Proxy and the PDN GW. ? The H2 reference point between the 3GPP AAA Server and the HA. ? The SWm reference point between the 3GPP AAA Server/Proxy and the ePDG.