ATM Based Networking
Today, there's much talk about information highways and Asynchronous Transfer Mode (ATM). Just as the Internet revolutionized world-wide communications, ATM brings new meaning to high-speed networking.
By: Ali Akbar Arbab
Oct 11 - 17, 1999
ATM is the next generation of networking. It promises to be the key networking enabler for existing and emerging applications in fields like science, medicine, and education. Medical imaging applications, for example, allow you to transform and store x-rays, CAT scans, and MRI images in digital form. These digital images often need to be accessed by several physicians at the same time. Transporting them across a network to these physicians requires a great deal of bandwidth. A network must support high-speed, yet reliable, data transmission to support this application.
In universities around the world, the classroom can be extended far beyond its physical boundaries with the help of ATM. With distance-learning applications, you can be part of a class even when you're thousands of miles away. You can interact with others just as if you were there.
Soon, you'll be able to use ATM for multimedia applications, videoconferencing, and even video on demand. If you're interconnecting your LANs, ATM addresses your growing bandwidth requirements.
But perhaps the most important benefit of ATM is that it can save you money. By allocating only the bandwidth needed by your applications, ATM provides direct bandwidth savings, which may lead to significant cost savings. With ATM, you use only the bandwidth you need, and you can use it efficiently and reliably.
ATM is the networking technology that satisfies these requirements. For LAN users, you'll get more bandwidth with ATM than with many of today's LANs. You can begin to use new applications and improve the performance of existing applications. ATM also provides more flexible bandwidth for your wide area network. WAN users can expect enhanced bandwidth management and bandwidth on demand, which, in turn, can reduce costs.
No matter what your business - banks and insurance corporations, outsourcers, or service providers - ATM is the technology that can save you money and move your networks into the future. You can migrate toward ATM with frame relay, or you can implement ATM today in your existing networks. With efficient bandwidth on demand, you use only the bandwidth you need.
ATM protocols are capable of providing a homogenious network for all traffic types. The same protocols are used regardless of whether the application is to carry conventional telephony, entertainment video, or computer network traffic over local area networks (LANs), metropolitan area networks (MANs), or wide area networks (WANs).
ATM technology is based on small, constant-sized cells that permit sufficiently rapid switching that multiple isochronous data can be statistically multiplexed together, along with computer network traffic. No longer will a communications channel be limited to a fixed data rate because of time-division multiplexing protocols, rather any application uses only the bandwidth required. If an application requires additional bandwidth for heavy data, it can request the additional bandwidth. Statistical multiplexing provides for "bandwidth on demand".
ATM protocols are designed to be scalable in bandwidth, with the ability to support real multi-media applications. ATM is often thought to be fiber-based because it is a critical part of the Broadband-ISDN protocol suite. There are standards in place today to implement ATM over OC-1 (51 megabits-per-second) to OC-48 (2.488 gigabits-per-second). However, ATM can be run over any media if engineered correctly.
Next-Generation Networking Technology
There are many reasons why ATM will be the networking technology for the near future and beyond. The success of this technology has not been left to chance, because ATM technology is been engineered in a manner to proactively address the problems that will be encountered with next-generation networks.
We are entering the third generation of communications networking, where multimedia applications will proliferate. One reason that ATM will be succeed is that ATM technology is designed to handle all aspects of multimedia --- video, audio, and data --- on the same network, with the same protocols regardless of whether the network is a LAN, MAN, or WAN.
Another reason for the likely success of ATM is that this networking technology will provide for sufficient improvements in capability to justify the expense of the investment in new technology. ATM and Broadband-ISDN technologies are scalable in bandwidth due to standards for true gigabit-per-second networks, and scalable in number of network nodes due to the switched network architecture.
The most important reason for the impending success of ATM is that this technology is standards-based. Standards and interoperability are the most important factors behind inter-networked communications. Networking standards that are technically sound and rigidly followed are more important than many technical limitations within a system. Without interoperability, it is not a network!