Overview

This page provides a brief overview of mobile agents and of the work here at Dartmouth.

A mobile agent is a program that can migrate from machine to machine in a heterogeneous network. The program chooses when and where to migrate. It can suspend its execution at an arbitrary point, transport to another machine and resume execution on the new machine. In the picture below, an agent carrying a mail message migrates first to a router and then to the recipient's mailbox. The agent can perform arbitrarily complex processing at each machine in order to ensure that the message reaches the intended recipient.

Mobile agents have several advantages over the traditional client/server model.

• Efficiency
  Mobile agents consume fewer network resources since they move the computation to the data rather than the data to the computation.
• Fault tolerance
  Mobile agents do not require a continuous connection between machines.
• Convenient paradigm
  Mobile agents hide the communication channels but not the location of the computation.
• Customization
  Mobile agents allow clients and servers to extend each other's functionality by programming each other.

Notable mobile agent systems include:

• Telescript and Odyssey from General Magic
• ARA (Agents for Remote Access)
• TACOMA
• IBM Aglets

A mobile-agent system called D'Agents is under development at Dartmouth College. The ultimate goal of D'Agents is to support applications that require the retrieval, organization and presentation of distributed information in arbitrary networks. Some of the research areas are:

• Security mechanisms
• Support for mobile and partially connected computers
• Navigation, network sensing and resource discovery tools
• Automatic indexing, retrieval and clustering techniques for text and other documents

D'Agents is used in several information-retrieval and workflow applications.

See the research page for more details.

Last updated on January 27, 1996