 Subscription Profile An HSS has per subscriber static addressing information for each APN within the subscription profile (see the APN-Configuration AVP and the Served-Party-IP-Address AVPs defined for the S6a/S6d-interfaces in [111]). Similarly for the HLR see the PDP-Address and Ext-PDP-Address parameters defined for the Gr-interface [53]. In the case of IPv6 address/prefix, the IID should be all zeros, which implies that it is not possible, according to standards, to assign a full IPv6 address to a UE. Even if a IPv6 address were signaled over the Gr/S6a/S6d-interface to an SGSN or an MME, there is no guarantee that the IID would be delivered to the UE. In addition, even if the IID gets delivered to the UE, there is no guarantee that the UE would use it for configuring other than the link-local address. When static addressing information comes from a subscription profile, an SGW includes the static address/prefix information into the PDN Connection activation signaling. The PGW then either authorizes or denies the use of the static address/prefix. Even in the static addressing case, the PGW should select the IID for the UE. Otherwise, there is a theoretical chance for duplicate link-local addresses on the 3GPP link. As for 3GPP Release-11, GTPv2 specifications [3] state that the IID may be received from the HSS subscription profile. This obviously contradicts the S6a/S6d (and HSS) specifications [111]. AAA Infrastructure In a case of RADIUS (and Diameter likewise), an external AAA server can assign a static IPv6 prefix to a UE using the Framed-IPv6-Prefix attribute in the Access-Accept IPv6 in 3GPP Networks message. The IID is still assigned by the PGW and included in the Framed-Interface-Id attribute in the Access-Request and Access-Accept messages. The (S)Gi-interface specification as of Release-11 [25] is not clear whether the AAA server is allowed to override the IID, thus it is safer to assume that this is not the case. The 3GPP standards are not clear either what to put into the relevant Framed-IP* attr