Gregory G. Finn

VISA: Netstation's virtual Internet SCSI adapter

In this paper we describe the implementation of VISA, our Virtual Internet SCSI Adapter. VISA was built to evaluate the performance impact on the host operating system of using IP to communicate with peripherals, especially storage devices. We have built and benchmarked file systems on VISA-attached emulated disk drives using UDP/IP. By using IP, we expect to take advantage of its scaling characteristics and support for heterogeneous media to build large, long-lived systems. Detailed file system and network CPU utilization and performance data indicate that it is possible for UDP/IP to reach more than 80% of SCSIs maximum throughput without the use of network coprocessors. We conclude that IP is a viable alternative to special-purpose storage network protocols, and presents numerous advantages.

An integration of network communication with workstation architecture

A workstation may be thought of as a group of cooperatively connected subsystems. Point--to--point channels may be used to create a small--scale Gigabit LAN to which these subsystems are attached as nodes. The architectural focus of such a workstation shifts towards its internal LAN. An attractive attribute of this LAN is that its aggregate capacity scales linearly with the number of nodes attached to it.If the link--layer of the internal LAN is made equivalent to the link--layer of the external LAN, interior nodes become directly accessible externally. Except for latency the distinction between whether a node is inside a workstation versus outside it need not be significant. This property is particularly attractive for distributed communication--intensive applications.

An experimental multimedia mail system

A computer-based experimental multimedia mail system that allows the user to read, create, edit, send, and receive messages containing text, images, and voice is discussed.

Atomic: A High-Speed Local Communication Architecture

ATOMIC is an inexpensive high-speed LAN built by USC/ISI. It is based upon Mosaic technology developed for fine-grain, message-passing, massively paraIiel computation. Each Mosaic processor is capable of routing variable length packets, while providing added value through simultaneous computing and buffering. ATOMIC adds a general routing capability to the native Mosaic wormhole routing through store-and-forward and path concatenation. ATOMIC aggregate bandwidth scales as the number of nodes increases, and it has a small interface cost. Each ATOMIC channel has a data carrying capacity of 480 Mb/s. A prototype ATOMIC LAN has been constructed along with host interfaces and software that provides full TCP/IP compatibility. Using ATOMIC, 1500-byte packets have been exchanged between hosts at an aggregate transfer rate of more than 1 Gb/s. Other tests have demonstrated throughput of 5.25 million packets per second over a single Mosaic channel. The architecture is flexible both in topology and functionality. This paper describes the architecture and performance of ATOMIC.

A global X-bone for network experiments

A global Internet overlay testbed is being deployed to support the distributed, shared use of resources for network research. The Global X-Bone (GX-Bone) augments the X-Bone software system, enhancing its coordination mechanisms to support deployment of local overlays to world-wide, shared infrastructure. The GX-Bone is based on the X-Bones Virtual Internet Architecture which extends the Internet for both concurrent, parallel and recursive overlays and provides decentralized, automated deployment and management. GX-Bone supports host visualization through the NetFS file system, granting individual users compartmentalized access and control of host and router configuration and the DataRouter extension to IP loose source routing that supports application control of network-layer forwarding. GX-Bone can be installed on user-modified kernels, uniquely supporting both conventional kernel-level protocol development and coordinated global infrastructure sharing.

The use of message-based multicomputer components to construct gigabit networks

The typical node of a message-based multicomputer consists of a microprocessor, router and memory. At the California Institute of Technology, the Mosaic project has integrated such a node onto a single chip. That reduction in scale fundamentally changes the scope of node application, since nodes become both very small, and inexpensive.Mosaic nodes may be employed to process, to generate, or to receive data. Since the router in a Mosaic node is independent of the microprocessor, computation and routing take place simultaneously. These nodes may be used to create general purpose gigabit LANs. They may also be used to create special purpose gigabit networks to interconnect instrumentation within spacecraft or aircraft.The ATOMIC project at USC/ISI is using Mosaic nodes to prototype a gigabit LAN testbed. This testbed is operational. Networking and administration software provides full TCP/IP compatibility. Packets have been exchanged between two interfaces at a rate above one gigabit per second (Gb/s).An individual ATOMIC interface is both inexpensive and small, consisting of one Mosaic chip, four SRAM chips and clock logic. Two interfaces easily fit onto a postcard-sized circuit board. Their low cost makes it practical to include several interfaces within a host, providing an interior Gb/s distribution network, multiple access points to the LAN for greater performance or redundancy, and other capabilities that are not yet fully explored. The results reported in this paper represent actual data obtained from the prototype.

DynaBone: dynamic defense using multi-layer Internet overlays

DynaBone provides a dynamic defense against distributed denial-of-service attacks among private groups of networked systems. It uses multi-layer Internet overlays to apply encryption, routing, and configuration diversity, providing multiple alternate networks over which traffic is automatically routed. The DynaBone software has been implemented and demonstrated to utilize as many as 50 concurrent interior networks, while providing a single network view to the end systems and applications.

ATOMIC: A Low-Cost, Very-High-Speed, Local Communication Architecture

ATOMIC1 is an inexpensive O(gigabit) speed LAN built by USC/ISI. It is based upon Mosaic technol ogy developed for fine-grain, message-passing, massively parallel computation. Each Mosaic processor is capable of routing variable length packets, while providing added value through simultaneous computing and buffering. ATOMIC adds a general routing capability to the native Mosaic wormhole routing through store-and-forward. ATOMIC scales linearly, with a small interface cost. Each ATOMIC channel has a data carrying capacity of 500Mbls. A prototype ATOMIC LAN has been con structed along with host interfaces and software that pro vides full TCP/IP compatibility. Using ATOMIC, 1J00 byte packets have been exchanged between hosts at an aggregate transfer rate of more than lGbls. Other tests have demonstrated throughput of 5.25 million packets per second over a single Mosaic channel. This paper describes the architecture and performance of ATOMIC.

Task force on network storage architecture: Internet-attached storage devices

Networks such as HiPPI, SSA and Fibre Channel are becoming the access technology of choice for peripherals such as disk drives, tape drives and disk arrays. These networks scale better than traditional I/O channels, connecting more devices over greater distances and providing greater aggregate bandwidth. More complex protocols are required for network interfaces than for channels. In most cases, specially developed protocols are used, rather than existing standards such as TCP/IP, due to perceived differences in functionality, focus, complexity and especially performance. We reason that most of these concerns either reflect misunderstanding of the IP suite or are being met as the suite evolves. We further argue that the benefits of using IP, including wide area connectivity, cross media bridging and reduced R&D, are substantial. Therefore, we feel that IP is an appropriate choice for a storage device and should be the protocol of choice for systems implementers.

The DynaSat Information Architecture for Fractionated Satellite Systems

DynaSat is a dynamic satellite information architecture that supports adaptive, faulttolerant, and secure communication and resource sharing for distributed (fractionated) satellite systems. It supports safe, robust, and secure sharing and virtualization of both cluster and ground capabilities by combining a COTS secure hypervisor and trusted resource control and multiplexing software with secure overlays. DynaSat leverages USC/ISI’s X-Bone overlay network and NetStation distributed PC architecture systems to deliver a space-based Internet for distributed satellite data collection applications. The result is a configuration-based approach that enables rapid implementation, simple operation, and provides programmers a familiar Internet-based environment. The architecture also supports service import/export to external ground users. This document provides an overview of the DynaSat architecture, discusses its design and resulting capabilities and advantages for fractionated satellite systems.