The fifth layer of the Web Interaction Model is Hardware. Hardware consists of the physical components of Web interaction, from back-end equipment such as a UNIX server for storing the Web site's supporting database; to dial-up or dedicated data connection lines; to the
through which the information is transmitted; to the end user's PC, where the information is requested and
Click the link below to see a pictorial representation of the hardware layer .
Networks Internet Layer
In the Web Interaction Model, networks and hardware are separated to help articulate how the Web works and to conceptualize Web site requirements. Keep in mind that every network uses hardware to operate.
Networks are made up of hardware plus the systems for identifying components and regulating traffic flow. To build on the familiar Information Superhighway metaphor, networks can be seen as the highway
system, while hardware can be seen as the physical roads, bridges, and entry ramps of the highway system. Hardware creates the physical platform for the Internet to function.
The following diagram describes some of the basic hardware and connectivity components that are necessary for Web implementations:
|Engineering Group, Hub:
||Interconnects multiple devices in a network, thereby enabling distribution of information among the devices connected to it.
||The server stores and forwards URLs and resources (such as Web pages, images, other data).
| Internet, Extranet Clients:
||Client [CPU, hard drive, monitor] - The client hosts the browser that allows users to access and display Web resources.
|Dial access (Sales People) Modem:
||Used when dial-up services are necessary. When analog telephone lines are used to access the Internet, a modem converts digital to analog signals (outgoing traffic) and from analog to digital (incoming traffic). DSU/CSU modems are used for T1 or fractional lines. Digital modems do not need to convert from digital to analog, but maintain digital from end to end (for example, for use with ISDN or ADSL lines).
||Connects two or more IP networks and routes traffic based on IP addresses.
|Physcial Connections, Connectivity:
||The physical connections among network hardware, such as cables, phone lines, or other connection lines. A primary connectivity issue is bandwidth, which is the maximum amount of information that the line can transmit per unit of time. (Home computers often connect via telephone lines, while businesses usually use connections with greater bandwidth, such as T1 lines, ISDN lines, or DSL.)
|Project Management Server:
||The server is a computer that is dedicated to storing data or running applications, processes, and services.
In the next lesson, you will see how all five Web layers interact in a real-time transaction. You will use the Web Interaction Model to explain how resources are requested and received via the Web.