David W. Robertson

Intra and Interdomain Circuit Provisioning Using the OSCARS Reservation System

With the advent of service sensitive applications such as remote controlled experiments, time constrained massive data transfers, and video-conferencing, it has become apparent that there is a need for the setup of dynamically provisioned, quality of service enabled virtual circuits. The ESnet on-demand secure circuits and advance reservation system (OSCARS) is a prototype service enabling advance reservation of guaranteed bandwidth secure virtual circuits. OSCARS operates within the energy sciences network (ESnet), and has provisions for interoperation with other network domains. ESnet is a high-speed network serving thousands of Department of Energy scientists and collaborators worldwide. OSCARS utilizes the Web services model and standards to implement communication with the system and between domains, and for authentication, authorization, and auditing (AAA). The management and operation of end-to-end virtual circuits within the network is done at the layer 3 network level. Multi-protocol label switching (MPLS) and the resource reservation protocol (RSVP) are used to create the virtual circuits or label switched paths (LSPs). quality of service (QoS) is used to provide bandwidth guarantees. This paper describes our experience in implementing OSCARS, collaborations with other bandwidth-reservation projects (including interdomain testing) and future work to be done.

A User Driven Dynamic Circuit Network Implementation

The requirements for network predictability are becoming increasingly critical to the DOE science community where resources are widely distributed and collaborations are world-wide. To accommodate these emerging requirements, the energy sciences network has established a science data network to provide user driven guaranteed bandwidth allocations. In this paper we outline the design, implementation, and secure coordinated use of such a network, as well as some lessons learned.

Virtual frog dissection: interactive 3D graphics via the Web

Abstract We have developed a set of techniques for providing interactive 3D graphics via the World Wide Web (WWW) as part of the “Whole Frog” project 1 . We had three goals: 1. 1. to provide K-12 biology students with the ability to explore the anatomy of a frog with a virtual dissection tool; 2. 2. to show the feasibility of interactive visualization over the Web; and 3. 3. to show the possibility for the Web and its associated browsers to be an easily used and powerful front end for high-performance computing resources. We have developed techniques to utilize the Common Gateway Interface 2 (CGI) capability of WWW servers to provide an interactive 3D visualization front end through Web clients. These techniques have been used to make a “Virtual Frog Dissection Kit” 3 . A student using this kit has the ability to view various parts of a frog from many different angles, and with the different anatomical structures visible or invisible. For example, the student can press “form” buttons that indicate that he or she wants to view the frog from above, with the exterior and skeleton removed. An advantage to this technique, as opposed to dissecting a real frog, is that undissection is as easy as dissection. The kit has a forms 4 -based interface. Form submission results in a call to a CGI script, which in turn contacts a continuously running process on a more powerful machine to accomplish the graphics rendering of a large 3D data set representing the frog and its internal organs. The resulting image is converted to Graphics Interchange Format (GIF) encoding. When that process completes generation of the image, it passes the location of the image file and control back to the script which rewrites the image on the client. While this might sound awkward, the overall process is quite similar to how all rendering systems work, with the image being written into a local frame buffer, or sent across the network as an X-window image.

Distributed scientific video movie making

A description is given of a versatile, low-cost, video movie-making system for generating and displaying scientific graphics from remote supercomputers. The system makes video movies by single-frame animation from the output of time-dependent, numerical simulations typically done on supercomputers. It uses extensive data compression to permit its use over wide area, as well as local area networks. The system demonstrates an easily used, elementary visualization capability for time-dependent data in a heterogeneous, distributed computing environment.<<ETX>>

Distributed visualization using workstations, supercomputers, and high speed networks

A collaboration designed to demonstrate the possibilities of access to supercomputers via the high-speed wide-area networks in order to carry out sophisticated, interactive visualization on local workstations is described. The test case was visualization of 3D magnetic resonance imaging data, with a Vray performing surface reconstruction to generate a set of triangles. The resulting geometric data was sent to a local workstation to be rendered, with minor enhancements to current network protocols enabling effective utilization of the 45 Mb bandwidth of a T3-based network.<<ETX>>

The software bus: A vision for scientific software development☆

Abstract We describe a new initiative at the Lawrence Berkeley Laboratory to provide a software development framework for a broad range of scientific problems. The initiative will use object oriented-programming to produce interoperable software components. These will include user interfaces and common graphics as well as scientific program modules. A standard interoperation protocol, the software bus, will be used to allow the modules to communicate with each other in much the same way that a backplane or network allows separate hardware module to cooperate.

Parallelization of Radiance For Real Time Interactive Lighting Visualization Walkthroughs

Radiance is a software package developed at Lawrence Berkeley National Laboratory for lighting visualization. Lighting visualization predicts how lighting would appear if a modelled scene were to be physically realized. Unlike most lighting systems, Radiance physically models the effects of lighting, providing an image that is closer to physical reality. This is of obvious benefit to architects and lighting designers. Such visualizations are computationally expensive: rendering a single image can take hours on a standard workstation environment. Ideally, an architect would like to be able to interactively navigate through a scene to get a full impression of the true appearance of a particular model. With this goal in mind, we have (1) developed a geometric-based method (point cloud) to reuse pixels from a previous frame and (2) developed a parallel, distributed memory implementation of Radiance and the point cloud using MPI for inter-processor communication.