Departmental Papers (CIS)

Date of this Version

March 2005

Document Type

Conference Paper


Copyright 2005 IEEE. Reprinted from Proceedings of the 24th Annual Joint Conference of the IEEE Computer and Communications Societies 2005 (INFOCOM 2005), Volume 2, pages 1196-1206.

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Mobile wireless devices have intermittent connectivity, sometimes intentional. This is a problem for conventional Mobile IP, beyond its well-known routing inefficiencies and deployment issues.

DHARMA selects a location-optimized instance from a distributed set of home agents to minimize routing overheads; set management and optimization are done using the PlanetLab overlay network. DHARMA's session support overcomes both transitions between home agent instances and intermittent connectivity. Cross-layer infomation sharing between the session layer and the overlay network are used to exploit multiple wireless links when available.

The DHARMA prototype supports intermittently connected legacy TCP applications in a variety of scenarios and is largely portable across host operating systems. Experiments with DHARMA deployed on more than 200 PlanetLab nodes demonstrate routing performance consistently better than that for best-case Mobile IP.



Date Posted: 25 February 2006