t at IP level, specifically from the UE point of view. This is important regarding the IPv6 NDP, which is piggybacked on top of Internet Control Message Protocol version 6 (ICMPv6) and makes extensive use of link scoped multicast. From the evolved bearer routers' perspective, they do not necessarily ever see multicast traffic that other routers send. The router originated IP multicast is always unicast to the UE at the bearer level. Similarly, the UE originated IP multicast is always unicast at the bearer level to all routers on the evolved bearer link. There is no real multicast over the evolved bearer. The IP level multicast over the evolved bearer link can be realized in two ways. First, the UE can always make multiple copies of the multicast packet and then unicast each copy to the respective router using the PDCP PDU type derived mechanism. Multiple copies implies unnecessary overhead over the radio interface, but from the forwarding point of view in the network there is no difference between IP multicast or unicast. Second, yet another PDCP PDU type could be reserved for the UE originated IP multicast - see Table 6.1. Using this approach only one copy of the packet would be sent over the radio interface and the eNodeB would take care of doing the required copies of the IP packet and delivering those further to other routers, namely to the SGW and PGW routers. Having evolved bearer routers to respond to Duplicate Address Detection (DAD) and address resolution is little burden. Most of the Neighbor Discovery Protocol operations can be handled with precomputed answers anyway. Supporting the NDP Redirect might now make sense in the evolved bearer. The assump- tion in that case is the evolved bearer routers should have some type of out-of-band knowl- edge of each others' presence, used link-local addresses, and other address management. Future of IPv6 in 3GPP Networks Multiple IPv6 Prefixes Per Bearer and Traffic Steering The interesting question is how an evolved bearer appears to a UE at the IP layer. The UE s