What is a WAN (Wide-Area Network)?

A wide-area network (or WAN) is a computer network that connects smaller networks. Since WANs are not tied to a specific location, they allow localized networks to communicate with one another across great distances. They also facilitate communication and the sharing of information between devices from anywhere in the world.

What Does a Wide-Area Network Do?

WANs allow organizations to create unified networks so that employees, customers, and other stakeholders can work together online, regardless of location.

WAN Examples

In an enterprise, a WAN is created to connect branch offices with one another. A WAN can also connect remote employees working at home with the company's main office. In a university or campus setting, students might rely on WANs to access library databases or university research. 

A bank, including its branch offices and ATM machines, is another example of an organization using a WAN. The branches may be in multiple U.S. states, or even located internationally, but they are all linked through various secure connections. Both bank employees and customers are users of the WAN.

Because WANs are the largest and most diverse form of a computer network in the world, it can be said that the internet is the world's largest WAN.

WAN Connections and Technology

Though WANs cover a large area, connections can be either wired or wireless. Wired WANs usually consist of broadband internet services and multiprotocol label switching (MPLS), which is a form of data-forwarding technology used to control traffic flow and speed up connection, while wireless WANs normally include 4G/5G and Long-Term Evolution (LTE) networks.  

Pros and Cons of Wired WAN

The pros of wired WAN connections generally revolve around security. In a wired network, devices must be physically wired into the network, making it more difficult for cyberattackers to gain unauthorized access. Additionally, with a physical connection required, organizations can control the number of devices that have access to the network. With fewer devices accessing the network, the risk of malware potentially infecting the infrastructure is reduced.

The other benefit of a wired WAN connection is speed. Unlike a wireless system that can be subject to outside interference, a wired network allows for a faster connection. 

The cons of wired WAN involve hardware. The more cabled connections, the more wires to manage. Further, when using a cabled network, employees can only gain access when there is a physical connection available, limiting mobility.

Pros and Cons of Wireless WAN

The pros of a wireless WAN are the opposite. The workplace can be anywhere, giving employees flexibility. The cons of a wireless WAN include both risk, as wireless networks are generally more vulnerable to attacks, and speed, as wireless networks are often slower.

To reduce costs, an organization might lease its WAN infrastructure as a service from a third-party service provider. The WAN may operate over a dedicated, private connection, or in a hybrid WAN scenario, have parts of it operating via a shared, public medium like the internet.

WAN Optimization and SD-WAN

WAN optimization aims to solve problems with WAN performance, usually related to speed. It is a process whereby network engineers reconfigure the network to ensure that certain applications receive more bandwidth and so can move faster through the network. This could be the case, for example, with a retailer that needs to send transaction data through as quickly as possible to its main data center.

WAN optimization has become crucial as data traveling through a WAN has increased in volume and complexity. Additionally, corporate WANs have expanded with remote workers, as those workers who used to be in an office connecting through the corporate WAN are now working from home and connecting through the public internet, yet their data must travel further and just as securely.

Software-defined wide-area networks (SD-WANs) have increased in popularity over the last several years. SD-WANs remove the manual labor required to optimize a WAN and instead rely on software to manage a WAN's connections, whether they are MPLS, 3G/4G, or broadband. SD-WANs increase an organization's efficiency by tracking application performance and using automation to select the best connectivity option. 

Because software does the job of choosing the best connection, it is not uncommon to have teleconferencing use a dedicated circuit and email use the public internet. User experience is key, especially as users may be accessing their organization's network in different environments via different applications. While considered a challenge for traditional WANs, SD-WANs are adept at supporting intensive, high-bandwidth applications, such as those involving voice or video. SD-WAN offloads such applications to local internet where possible.

SD-WANs also offer the ability to optimize connectivity to such cloud services as Amazon Web Services or Microsoft Azure. With the continued migration to Software-as-a-Service (SaaS), organizations and their customers expect their data to travel securely through the cloud.  

Further, an SD-WAN has management and reporting features that give a single view of WAN performance.

Understanding LAN and WAN

A local-area network (LAN) is a group of computers that are all located in the same small area and that all share the same connection. For example, the computers used by employees in a single office location would most likely be connected with a LAN. Another example of a LAN could be a network created by a local café that customers must sign in to first so that that they can access the internet. The café creates this rather than giving customers its Wi-Fi password.

WANs are made possible by connecting multiple LANs. 

Many people confuse LANs with another networking term, Ethernet. However, Ethernet is a network protocol that controls how data is transmitted over a LAN and is referred to as the IEEE 802.3 protocol. LANs are made possible because of Ethernet technologies. The main difference between Ethernet and LAN is that the Ethernet’s function is decentralized and that of the LAN is centralized. 

Additional acronyms for networks abound. A personal area network (PAN) is a network that covers a very small area, such as an enclosed room. The most popular wireless PAN network technologies are Wi-Fi and Bluetooth, while USB is the most popular form of wired PAN. A wireless headset, printer, or smartphone are all individual components that comprise a network. Indeed, many peripheral devices can actually be classified as computers because they have computing, storage, and network capabilities. 

A metropolitan area network (MAN) connects nodes in the same metro area. For example, a New York City company might have operations in buildings located not just in Manhattan but also nearby in Brooklyn and Jersey City, New Jersey, requiring its own network. For organizations to build this type of network, they use microwave transmission technology, but buildings can also be wired together using fiber-optic cable.

Yet another term is an internet area network (IAN). An IAN is a communications network that connects data and voice endpoints within a cloud environment over internet protocol (IP), replacing an existing LAN or WAN. In an IAN, a managed services provider hosts all communications and applications services in the cloud. An IAN platform essentially provides users with secure access to information anytime, anywhere via the internet.

Securing Your WAN

A virtual private network (VPN) creates a secure connection between networks, generally between one that is not secure (the public internet) and one that is secure (a company's WAN).  

Security gaps have long been seen as a major weakness in WANs, especially when users are accessing their devices in multiple locations, including their homes. As such, additional security measures, including firewalls and antivirus software, should be considered in order to prevent unauthorized access or compromise.

Not only does the use of a VPN help create connectivity in a WAN but it also encrypts data. However, the use of a VPN does not ensure the complete security of a WAN. IT professionals may need to install additional security protocols to deliver the level of security required for the organization. 

WAN security can be compromised when a single device is connected to multiple networks. For example, an individual uses the same iPhone for both work and personal use. For work, the individual connects the phone to the company's WAN, but for personal use, she accesses the internet via an unsecured Wi-Fi hotspot. Without a mobile device management or enterprise mobility management solution in place, security can be an issue.

Adopting SD-WAN in lieu of a plain WAN is one way to address security challenges. An SD-WAN solution must have integrated security. Without it, it becomes a potential attack vector. A secure SD-WAN improves the overall security of the business. Apart from security, other features of SD-WAN include improved user experience, lower total cost of ownership (TCO), simplicity, and multi-cloud readiness.

Learn more about integrating security with your SD-WAN to avoid common WAN security pitfalls. Check out FortiGate SD-WAN models and specs.