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Mobile networks typically involve a variety of network protocols and devices, in many cases coupled with quickly evolving topologies (as devices are turned on and off and devices move across network boundaries). In this context, resource location and discovery becomes a difficult problem. Current large-scale systems designed for IP-based networks such as the Internet rely on static, hierarchical name resolution and resource location systems such as DNS or LDAP, or on limited autoconfiguration systems such as DHCP, that are not well-suited to quick updates and changes in topology because of their dependence on a central server and its static, hierarchical nature. A resource location and discovery system for mobile networks must be able to adapt to an evolving network topology and maintain correct resource location even when confronted with fast topological changes. It should also work in an ad hoc network environment, where no central server is available and the network can have a short lifetime, and it should connect across networks that might be operating on different network protocols or be connected through a third network (eg, the Internet) as long as the nodes in the network implement the system. To avoid redundancy, the system must be suited to resolve the location not just of node names but of any resource, such as services, people, etc.

In this paper, we present Nom, a resource location and discovery system based on a Peer-to-Peer protocol that fulfills those requirements. We analyze the protocol and we discuss how a testbed implementation of the protocol was used to provide name resolution for a completely distributed, self …