Résumé : ORFA is a user-level protocol that aims at providing an efficient remote file system access. It uses high bandwidth local networks and their specific API to directly connect user programs to data in the remote server. The ORFA model and its first implementation are described in this paper. The client is an automatically preloaded shared library that transparently overrides glibc I/O calls and redirect them to the server if concerned files are remote. The server may be a user program implementing a custom memory file system, or accessing native file systems.