Purpose of WAN Wide Area Network

Purpose of WAN Wide Area Network

This article describe the purpose of a WAN (Wide Area Network). Why WAN is necessary?
Companies use LAN networks to provide internal communication, even when these LANs are far apart. Wide area networks (WAN) are used to connect remote LANs. A WAN can provide coverage to a city, a country or a global region. WANs are owned by a service provider, and companies pay a fee to use the provider's WAN network services.

Why WAN is necessary? 

WANs operate beyond the geographic scope of a LAN. As shown in Image, WANs are used to interconnect the company's LAN to remote LANs in branches and remote employee locations.

A WAN is owned by a service provider . To connect to remote sites, an organization must pay a fee to use the provider's network services. WAN service providers include service providers, such as a telephone network, a cable company or a satellite service. Service providers provide links to interconnect remote sites, in order to transport data, voice and video.
Instead, LANs are normally owned by the organization and are used to connect computers, peripherals and other local devices in a single building or other small geographic area.

ARE WANS NECESSARY?

Without the WAN, the LAN would be a series of isolated networks. LANs provide speed and profitability for data transmission in relatively small geographic areas. However, as organizations expand, companies require communication skills between geographically separate sites. The following are some examples:

• Regional offices or branches of an organization need to be able to communicate and share data with the central site.
• Employees who travel through company businesses often need access to information located in business networks.

Home computer users also need to send and receive data over increasingly large distances. These are some examples:

• Today, consumers normally communicate with banks, stores and a variety of suppliers of goods and services through the Internet.
• To investigate for their classes, students access indexes of libraries and publications located in other parts of the country and the world.

Computers cannot be connected across a country, or the world, with physical cables. Therefore, different technologies evolved to support this communication requirement. The Internet is increasingly used as an economic alternative to enterprise WANs.

EVOLUTION OF THE NETWORKS

Each company is unique, and the way in which an organization grows depends on several factors. These factors include the type of products or services the company sells, the management philosophy of the owners and the economic climate of the country in which the company operates.
The example used in this chapter is that of a fictitious company called SPAN Engineering. Watch the network requirements change as this small local business becomes a global business.

SMALL OFFICE

SPAN engineering, an environmental consulting company, developed a special process to convert household waste into electricity and works on a small pilot project for the municipal government in your local area. The company, which has been operating for four years, has grown and has 15 employees: six engineers, four computer-aided drawing designers (CAD), a receptionist, two executive partners and two administrative assistants.
The administration of SPAN Engineering is working to obtain large-scale contracts once the pilot project satisfactorily demonstrates the feasibility of the process. Until then, the company must manage costs carefully.
For its small office, SPAN Engineering uses a single LAN to share information between computers and to share peripherals, such as a printer, a large-scale plotter (for printing engineering drawings) and fax machines. Recently, the LAN was updated to provide an economical voice over IP (VoIP) service, in order to save on the costs of separate telephone lines for employees.
The Internet connection is made through a common broadband service called DSL, which is supplied by the local telephone service provider. With so few employees, bandwidth is not a significant problem.
The company cannot afford internal IT support personnel, so it uses the support services of the DSL provider. The company also uses a web hosting service, instead of buying and operating its own FTP and email servers.

CAMPUS NETWORK

Over the course of five years, SPAN Engineering grows rapidly. Shortly after the successful implementation of the first pilot plant, the company was hired to design and implement a large-scale waste conversion facility. Since then, SPAN has obtained other projects in neighboring municipalities and other parts of the country.
To handle the additional workload, the company hired more staff and rented more office space. Now it is a small to medium sized company with several hundred employees.
Several projects are developed at the same time, and each requires a project manager and support staff. The company is organized into functional departments, and each department has its own organizational team. To meet the growing needs, the company moved to several floors of a larger office building.
As the company expanded, the network also grew . Instead of a single small LAN, the network now consists of several subnets, each destined for a different department. For example, all engineering personnel are on one LAN, while the marketing staff is on a different LAN. These various LANs come together to create a business network , or campus, that spans several floors of the building.

Now, the company has internal IT staff to support and maintain the network. The network includes dedicated servers for email, data transfer and file storage, as well as web-based applications and productivity tools. In addition, the company has an intranet to provide internal documents and information to employees, while an extranet provides project information to designated customers.

BRANCH NETWORKS

SPAN Engineering was so successful with its patented process that, another six years later, the demand for its services increased enormously. There are new projects in progress in several cities. To manage these projects, the company opened small branches near the project sites.
This situation presents new challenges for the IT team. To manage the provision of information and services throughout the company, SPAN Engineering now has a data center, which houses the various servers and databases of the company.
To ensure that all parts of the company can access the same services and the same applications regardless of the location of the offices, the company must now implement a WAN .

In addition, for branches that are in nearby cities, the company decides to use dedicated private lines through its local service provider. However, for offices that are located in other countries, the Internet is an attractive WAN connection option. While connecting offices over the Internet is an economical option, it presents security and privacy issues that the IT team must address.

DISTRIBUTED NETWORK

Now, SPAN Engineering has 20 years of operation and has thousands of employees distributed in offices around the world. The cost of the network and related services implies a significant expense. The company seeks to provide its employees with the best network services at the lowest possible cost. To increase profitability, SPAN Engineering must reduce its operating expenses. It relocated some of its offices in less expensive areas and also promotes distance work and virtual work teams.
To increase productivity and reduce costs, Web-based applications are used, including web conferences, e-learning and online collaboration tools. Virtual private networks (VPN) from site to site and remote access allow the company to use the Internet to easily and securely connect with employees and facilities worldwide.
To meet these requirements, the network must provide the converged services and secure Internet WAN connectivity necessary for individuals and offices and remote.