RFC 2005 (rfc2005) - Page 2 of 5

Applicability Statement for IP Mobility Support

RFC 2005           Mobile IP Applicability Statement        October 1996


   -- a topologically significant address -- to which standard IP
   routing mechanisms can deliver packets.

   The Mobile IP protocol defines the following:

   - an authenticated registration procedure by which a mobile node
     informs its home agent(s) of its care-of address(es);

   - an extension to ICMP Router Discovery [RFC 1256] which allows mobile
     nodes to discover prospective home agents and foreign agents; and

   - the rules for routing packets to and from mobile nodes, including
     the specification of one mandatory tunneling mechanism ([MIP-IPinIP])
     and several optional tunneling mechanisms ([MIP-MINENC] and
     [RFC 1701]).

2. Applicability

   Mobile IP is intended to solve node mobility across changes in IP
   subnet.  It is just as suitable for mobility across homogeneous media
   as it is for mobility across heterogeneous media.  That is, Mobile IP
   facilitates node movement from one Ethernet segment to another as
   well as it accommodates node movement from an Ethernet segment to a
   wireless LAN.

   One can think of Mobile IP as solving the "macro" mobility management
   problem.  It is less well suited for more "micro" mobility management
   applications -- for example, handoff amongst wireless transceivers,
   each of which covers only a very small geographic area.  In this
   later situation, link-layer mechanisms for link maintenance (i.e.
   link-layer handoff) might offer faster convergence and less overhead
   than Mobile IP.

   Mobile IP scales to handle a large number of mobile nodes in the
   Internet.  Without route optimization as described in [MIP-OPTIM],
   however, the home agent is a potential load point when serving many
   mobile nodes.  When home agents become overburdened, additional home
   agents can be added -- and even dynamically discovered by mobile
   nodes -- using mechanisms defined in the Mobile IP documents.

   Finally, it is noted that mobile nodes are assigned (home) IP
   addresses largely the same way in which stationary hosts are assigned
   long-term IP addresses; namely, by the authority who owns them.
   Properly applied, Mobile IP allows mobile nodes to communicate using
   only their home address regardless of their current location.  Mobile
   IP, therefore, makes no attempt to solve the problems related to
   local or global, IP address, renumbering.




Solomon                     Standards Track