Network transparency in an internetwork environment

Network transparency refers to the ability of a distributed system to hide machine boundaries from users and programs; all resources are accessed in the same manner, independent of their location. Network transparency has been shown to be highly valuable and achievable in the local area network environment. In contrast, access to remote resources in long haul networks traditionally is not transparent; substantially different access methods are required and only a limited set of operations is available. In this dissertation, we demonstrate that transparency across a system of local area networks connected by long haul links is both highly desirable and technically feasible. Three strategies are proposed to overcome the performance limitations of the communications media: exploitation of locality, semantics-based protocol design, and remote process execution. A distributed name cache is shown to dramatically reduce the overhead of name management for an internet operating system. New, higher semantic level message primitives for the most frequent user commands are described and their impact on reducing network traffic is demonstrated. A testbed based on the Locus operating system, extended to operate across an internet consisting of LANs connected by long haul links, was implemented. Performance measurements from the testbed were used to evaluate the effectiveness of the three strategies and to demonstrate the viability of transparency in an internet environment.