DATA COMMUNICATIONS AND NETWORKING FOR

TODAY’S ENTERPRISE

Effective and efficient data communication and networking facilities are vital to any

enterprise. In this section, we first look at trends that are increasing the challenge for

the business manager in planning and managing such facilities. Then we look specifically

at the requirement for ever-greater

transmission speeds and network capacity.

Trends

Three different forces have consistently driven the architecture and evolution of

data communications and networking facilities: traffic growth, development of new

services, and advances in technology.

Communication traffic, both local (within a building or building complex) and

long distance, both voice and data, has been growing at a high and steady rate for

decades. The increasing emphasis on office automation, remote access, online

transactions, and other productivity measures means that this trend is likely to continue.

Thus, managers are constantly struggling to maximize capacity and minimize

transmission costs.

As businesses rely more and more on information technology, the range of

services expands. This increases the demand for high-capacity networking and transmission

facilities.

In turn, the continuing growth in high-speed network offerings

with the continuing drop in prices encourages the expansion of services. Thus,

growth in services and growth in traffic capacity go hand in hand. Figure 1.1 gives

some examples of information-based services and the data rates needed to support

them [ELSA02].

Finally, trends in technology enable the provision of increasing traffic capacity

and the support of a wide range of services. Four technology trends are particularly

notable:

1. The trend toward faster and cheaper, both in computing and communications,

continues. In terms of computing, this means more powerful computers and

clusters of computers capable of supporting more demanding applications,

such as multimedia applications. In terms of communications, the increasing

use of optical fiber has brought transmission prices down and greatly

increased capacity. For example, for long-distance telecommunication and

data network links, recent offerings of dense wavelength division multiplexing

(DWDM) enable capacities of many terabits per second. For local area networks

(LANs) many enterprises now have Gigabit Ethernet backbone networks

and some are beginning to deploy 10-Gbps Ethernet.

2. Both voice-oriented telecommunications networks, such as the public switched

telephone network (PSTN), and data networks, including the Internet, are more

“intelligent” than ever. Two areas of intelligence are noteworthy. First, today’s

networks can offer differing levels of quality of service (QoS), which include

specifications for maximum delay, minimum throughput, and so on. Second,

today’s networks provide a variety of customizable services in the areas of network

management and security.

1.1 / DATA COMMUNICATIONS AND NETWORKING FOR TODAY’S ENTERPRISE