Multicast tunneling for grouped IPv6 Mobile clients
Original Publication Date: 2004-Feb-20
Included in the Prior Art Database: 2004-Feb-20
Mobile IPv6 nodes often move to different subnets. If these nodes are members of a global multicast group, the home agent for that subnet must tunnel multicast packets for each of the mobile nodes separately to the new location for each node. Tunneling is done by encapsulating the multicast packet in an IPv6 header addressed to the mobile node's new location. This increases Internet traffic considerably if there are a large number of mobile nodes. This article describes a new mechanism of multicast tunneling for grouped IPv6 mobile nodes.
Multicast tunneling for grouped IPv 6 Mobile clients
When a mobile node moves to a new network it sends a Binding Update to the home agent to inform the home agent of its new location. The mobile node must also send the home agent a list of global multicast addresses that it belongs to. For each multicast group the home agent will create a mapping from the original multicast group "G" to a new unused multicast group "H". The home agent then sends this list of mappings back to the mobile node as part of the Binding Acknowledgement message. The mobile node now joins the new multicast groups e.g. "H" on the network it is currently visiting.
Now when the home agent receives any multicast packet for one of the original multicast groups e.g. "G", it simply encapsulates these packets in another IPv6 packet addressed to the new multicast group e.g. "H" and sends the packet out into the Internet.
Thus, when a large number of mobile hosts are members of a multicast group "G", instead of tunneling a copy of each multicast packet to each of the hosts, the home agent now sends out only a single new multicast packet.