Source : Free On-Line Dictionary of Computing

Remote Reference Layer
     
         (RRL) Part of {Java}'s {Remote Method Invocation}
        protocol.  RRL exists in both the RMI {client} and {server}.
        It is used by the {stub} or {skeleton} {protocol layer} and
        uses the {transport layer}.  RRL is reponsible for
        transport-independent functioning of RMI, such as {connection
        management} or {unicast}/{multicast} {object invocation}.
     
        [Specification URL?]
     
        (1997-12-03)