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Simple Solutions for Locating Entities
Broadcasting: Simply broadcast the ID, requesting the entity to return its
current address.
•Can never scale beyond local-area networks (think of ARP/RARP)
•Requires all processes to listen to incoming location requests
Forwarding pointers: Each time an entity moves, it leaves behind a
pointer telling where it has gone to.
•Dereferencing can be made entirely transparent to clients by simple
following the chain of pointers
•Update a client’s reference as soon as present location has been found
•Geographical scalability problems:
–Long chains are not fault tolerant
–Increased network latency at dereferencing
Essential to have separate chain reduction mechanisms
Home-Based Approaches (1/2)
Single-tiered scheme: Let a home keep track of where the
entity is:
• An entity’s home address is registered at a naming service
• The home registers the foreign address of the entity
• Clients always contact the home first, and then continues
with the foreign location
