Web Commerce Security Design and Development

Ubiquity

Mark Weiser, a pioneer in ubiquitous computing, states that “ubiquitous computing has as its goal the enhancing of computer use by making many computers available throughout the physical environment, but making them effectively invisible to the user.”⁹

For Web commerce applications, computational resources have to exhibit ubiquity to the consumer through high-bandwidth communication links. One of the principal economic justifications for Web commerce is that the lowered cost of high-bandwidth network communication provides access to a larger pool of IT resources that sustain a high level of utilization.

Many organizations use a three-tier architecture to connect a variety of computing platforms such as laptops, printers, mobile phones, and PDAs to the wide area network (WAN). This three-tier architecture comprises the following elements:

• Access switches that connect desktop devices to aggregation switches
• Aggregation switches that control flows
• Core routers and switches that provide connection to the WAN and traffic management

Exploring the technical details, the three-tier approach results in latency times of 50 microseconds or more that result in problematic delays for Web commerce computing. For good performance, the switching environment should have a latency time of 10 microseconds or less. A two-tier approach that eliminates the aggregation layer can meet this requirement, using 10G (10Gigabits/sec) Ethernet switches and the forthcoming 40G and 100G Ethernet switches. ...