Structured peer-to-peer overlay network is an efficient solution for querying and retrieving resources spread between the peers. Unfortunately, key based routing of Distributed Hash Tables is simple when keys are known in advance, and at the service level this connot be always assumed. In this paper1, we present DHTeach, an e-learning application built on a totally distributed overlay network, where the problem of key definition is solved using an ad hoc description language. Moreover, DHTeach lays on a multicast application layer that organizes peers in order to make them able to receive the multimedia stream concurrently from a set of partners participating the class. The overall architecture is fully integrated and interoperable.