SMAC May 1999 Durkin - 2

INTRODUCTION

Although there have been exponential increases in Ethernet speeds as high as one gigabit per second and beyond the reality is that most high-speed Ethernets cannot operate anywhere near their potential. Why? Because Ethernets manage network traffic based on a 25-year-old protocol: CSMA/CD (carrier sense multiple access with collision detection). CSMA/CD is designed to manage information-packet collisions on the network. In such a collisionmanaged environment, high-speed networks only enable collisions to happen faster – especially when there are many users on the network. These collisions delay transmissions and generate additional network traffic in the form of collision-detection signals and subsequent repeat attempts to send packets to their destinations. Using CSMA/CD to manage traffic on a busy network can reduce network efficiency to as little as 24 percent of its rated potential. Although the CSMA/CD protocol has been exhaustively studied and improved upon over the years, it still operates on the assumption that collisions are inevitable. As long as it is assumed there will be collisions, there will be collisions. What if, however, it is assumed there will be no collisions? What if it is assumed there could be a protocol that precisely synchronized all data packets so that they would race to their destinations at maximum network speed in a "collision-less" environment? There is such a protocol: synchronous medium access control (U.S. Patent 4,811,365). The SMAC protocol was invented by Phillip Edward Manno, technical director of SyncAcess Inc. of Sacramento, Calif. The SMAC technology transcends collision-management with traffic-synchronization to enable both switched and non-switched Gigabit Ethernets to operate at near 100 percent efficiency. The protocol is designed to replace, overlay, or co-exist with CSMA/CD in all Ethernet networks in every transmission medium and on every computer platform. Furthermore, SMAC technology offers features that will make Gigabit Ethernets more competitive – and compatible – with ATM (asynchronous transfer mode), SONET (synchronous optical network), Fibre Channel, and FDDI (fiber distributed data interface) technologies. For example, the SMAC protocol supports resource reservation setup protocol (RSVP) and qualities of service (QoS) for real-time video-audio-data transmission. Gigabit Ethernets cannot guarantee RSVP or QoS. In cooperation with Altera Corrp. of San Jose, Calif, SyncAccess is targeting original equipment manufacturers in three specific markets: The global public network infrastructure for data and voice communications The Internet infrastructure that supports the World Wide Web Corporate wide area networks.
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