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4Chapter
Mobility
One major limitation of the current Internet is its inability to provide and support
mobility. is chapter discusses the solutions on mobility for IP communications.
Mobility solutions are engineered differently in different layers of the OSI, including
the physical, data-link layers, network, session, transport, and the application lay-
ers. We discuss a solution for mobility in relation to SIP in the application layer.
e mobility of nodes is handled in the application layer. e problem is that
a node that changes from one link to another is not able to maintain communica-
tion at the new location without changing or acquir