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ULIDs into the real addresses of the two terminals. Then, the packet is
sent over the address IP2A of terminal A to the address IP2B of
terminal B. When the SHIM sub-layer of terminal B receives the
packet, it translates the addresses back into ULIDs (IP1A for the
source and IP1B for the destination) before sending data up to the next
layer. Due to the matching between the ULID and the address
performed by the SHIM sub-layer, the changes of address are totally
transparent for the upper-layer protocols.
Figure 5.16. Example of matching in SHIM6
5.7.3. mCoA (Multiple Care-of-Addresses) in Mobile IPv6
MIP6 (Mobile IPv6) is the protocol used to manage mobility for
IPv6. In the IP mobility architecture, each mobile node has a static
HoA (Home Address) which is attributed by its home network. When
the mobile node enters a host network, it obtains a new, temporary IP
address known as the CoA (Care-of-Address). It informs its home
agent (HA), which is in the home network. The HA stores, in its cache
(Binding Cache), the match between the CoA and the HoA of the
mobile node. Then, if there is any traffic destined for the HoA, it is
intercepted by the HA and redirected to the mobile node’s true address
using an IP tunnel. Consequently, the mobility of the mobile node
becomes transparent to the corresponding nodes. The principle of
Mobile IPv6 is illustrated in Figure 5.17.
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