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
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!