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 SWm reference point between the 3GPP AAA Server/Proxy and the ePDG. - The reference point between the 3GPP AAA Server/Proxy and the EIR.