Role based access control (RBAC) allows users access to resources based on their competencies and responsibilities within an organization. Typically, RBAC is provided as a security mechanism for a single host at the operating system level. This allows the operating system to ensure that authenticated users have access to resources based on their assigned roles. RBAC is more challenging in peer-to-peer (P2P) systems, due to the lack of centralized administration. In this paper we discuss RBAC over a P2P network and we present an RBAC implementation in the JXTA P2P framework. JXTA is a popular open P2P technology specification.