Section: 5.17 Home eNodeB Multicast Packet Forwarding Function
Content: A Home eNodeB L-GW should receive and process multicast group membership report messages (e.g. according to RFC 3376 [62] / RFC 3810 [63]) sent either by the network accessed by LIPA or by the UE. Based upon these messages, the L-GW should forward multicast IP datagrams sent by the UE to the network accessed by LIPA, or from the network accessed by LIPA to the UE, as appropriate. The UE may implement RFC3376 [62] or RFC 3810 [63] to report multicast groups that the UE seeks to receive. To make UPnP/DLNA service advertisements sent with an IP TTL=1 available to UEs that employ LIPA, a proxying function in the L-GW may be implemented, e.g. to retransmit UPnP service advertisements to UEs after changing the source address. This proxying to the UE shall not be performed if the multicast packet is transmitted with an IPv4 or IPv6 link-local source address, RFC 3927 [64], RFC 4291 [65].