Measurements and Quality of Service Issues in Electronic Commerce Software Oriented System for Electronic Commerce Applica- Tion on Top of a Distributed System. 1.1 Quality of Service Layering

The performance of network and communication software is a major concern for making the electronic commerce applications in a distributed environment a success. The quality of service in electronic commerce can generically be measured by convenience, privacy/security, response time, throughput, reliability, timeliness, accuracy, and precision. We present the quality of service parameters, software architecture used in e-commerce, experimental data about transaction processing in the internet, characteristics of digital library databases used in e-commerce and communication measurements for such data. We present a summary of e-commerce companies and their status and give an example of electronic trading as an application. Quality of service control requires an understanding of the quantitative parameters at application, system, and network layers. The interplay among these parameters needs to be evaluated by building a transaction There are several eeorts which try to formalize the QoS requirements for distributed multime-dia systems 10]. There is no global agreement on the precise meaning and formal deenition of QoS. We partition the QoS parameters into two subsets, namely application-dependent parameters and application-independent parameters. We classify QoS parameters into three layers: user parameters, application parameters, and system parameters as shown in Table 1. The system parameters can be classiied into two categories: network and operating system parameters and device parameters. Since most electronic commerce applications require multi-media presentation to the customer from the venders, the quality of audio and video is important in addition to images, text and numbers. Application parameters describe requirements for application services and are speciied in terms of media quality and media relations. Media quality includes source/destination characteristics such as media data unit rate and transmission characteristics such as response time. Media relations specify relationships among media, such as media conversation, interstream synchronization , and intrastream synchronization. Other application parameters are convenience, price comparison and satisfaction, return policy, guarantee 1