tailieunhanh - Dịch vụ mạng thế hệ kế tiếp P12

Internet-Based Services It all started with Internet Service Providers (ISPs) offering to host a company’s website and email. ISPs can offer economies of scale and could cost effectively maintain a permanent connection to the Internet and offer dial-up solutions to their customers. The customers in return get a permanent presence on the Internet for their website and permanent email delivery service. In the corporate environments the move from centralised server and mainframe environments to peer-to-peer networks with local workgroup servers had started the return to centrally managed servers | Next Generation Network Services Neill Wilkinson Copyright 2002 John Wiley Sons Ltd ISBNs 0-471-48667-1 Hardback 0-470-84603-8 Electronic 12 Internet-Based Services INTRODUCTION - THE MOVE TO HOSTED SERVICES It all started with Internet Service Providers ISPs offering to host a company s website and email. ISPs can offer economies of scale and could cost effectively maintain a permanent connection to the Internet and offer dial-up solutions to their customers. The customers in return get a permanent presence on the Internet for their website and permanent email delivery service. In the corporate environments the move from centralised server and mainframe environments to peer-to-peer networks with local workgroup servers had started the return to centrally managed servers. In the early to mid-1990s technologies such as the Citrix WinFrame products enabled resurgence in the centralised management and delivery of enterprise applications. These two technology solutions combined with organisational desires to outsource functions of business activity seen to be non-core led to the opportunity for application hosting services. The idea of thin client computing was born and the web browser became the ultimate thin client application. Architectures such as the now famous three-tier architecture of client web server and back office database engine spawned the use of server side scripting and Java applications running either on the web server or in the web browser applets in this case and the n-tier architecture model was born. This model has given birth to application servers and the architecture of call servers and softswitches. This evolution of technology has enabled the growth in the service provider marketplace xSPs as they have become known including ISP - Internet service provider. 156 INTERNET-BASED SERVICES ASP - Application Service Provider. WASP - Wireless Application Service Provider. WISP - Wireless ISP. AIP - Application Infrastructure Provider. ITSP - .