What Is a Wide Area Network (WAN)? Definition, Types, Architecture, and Best Practices

Wide area network (WAN) is defined as a connected collection of telecommunication networks that are distributed across a large geographic area spanning multiple cities, territories, or nations so that the component networks can exchange data within the defined WAN group. This article discusses the types of WAN to choose from, its architecture components, and ten best practices for implementation. 

What Is a Wide Area Network (WAN)?

Wide area network (WAN) is a connected collection of telecommunication networks distributed across a large geographic area spanning multiple cities, territories, or nations so that the component networks can exchange data within the defined WAN group. 

Technically, any group of networks that aren’t within local proximity of each other forms a WAN. This means that the public internet that we use every day is a type of WAN as devices situated in opposite corners of the world can communicate with each other. However, in enterprise IT, a wide area network has a more specific application. It refers to a group of connected networks operating in a private environment, typically run by a single company, a conglomerate, a government, or a group of government agencies. 

Let’s say a company’s headquarters are in city A and it has branches in city B, C, and D, along with retail outlets in city E and F. The company needs a networking infrastructure that connects all of these locations without necessarily interacting with the public internet (prone to inconsistent speeds, downtime, and security risks, among others). 

And, the company will also have a local area network or LAN in cities A, B, C, D, E, and F individually. WAN helps connect these multiple LAN environments together and enable data exchange within this group of networked devices in six cities, aligning with the performance requirements of each location. This is how enterprise WAN typically works. 

Let us look at a few examples of WAN solutions available in the industry to understand this concept further. 

See More: How To Make Networks Ready for Cloud-First Era With SD-WAN

Examples of WAN solutions 

You may operate a WAN environment entirely through an in-house team without the support of an external solution provider. Your telecommunication carrier can enable connectivity between multiple locations through leased lines and multiprotocol label switching (MPLS) technology and leave the management of the network to you. However, there are solutions available to simplify WAN implementation and management: 

Example 1: Verizon Managed WAN 

Verizon is among the world’s leading telecom carriers and network solution providers. Its portfolio of business offerings includes managed wide area networks. Verizon not only implements WAN using its extensive infrastructure of leased lines and fiber cables, but it also looks after network management. You will receive regular performance reports, and Verizon will provide repair services for any customer premises equipment (CPE) in your local environment. 

Example 2: Cisco Meraki 

Meraki is Cisco’s lineup of network solutions, which includes LAN, Wi-Fi, mobile device management, and the internet of things (IoT), in addition to wide area networks. To help manage your WAN environment, Cisco provides dedicated software technology, wireless connectivity, and network analytics. It also WAN security solutions. 

Example 3: flexiWAN 

Announced in 2019, flexiWAN is the world’s first open-source solution for wide area networks and secure access service edge (SASE). It is entirely software-based, which means that it does not use physical network appliances like routers, switches, etc., to manage the WAN environment. flexiWAN is free for up to three instances in three different locations and customized as per your requirements. 

These three examples illustrate what a typical enterprise WAN implementation might look like. In this context, it is important to know the closely related concept of WAN optimization. WAN optimization is the collection of processes and network configurations that improve data exchange between multiple components of the WAN group. It will set up the network to allow maximum bandwidth available to applications, optimal performance, stringent security, and minimal downtime. When looking for the best WAN solution for your enterprise, ensure that WAN optimization is a top priority. 

See More: What Is Local Area Network (LAN)? Definition, Types, Architecture and Best Practices

Types of Wide Area Network (WAN)

WAN can be classified into two broad categories: switched WAN and point-to-point WAN. Apart from this, there are five types of WANbased on their underlying technology. Let’s first discuss the broad classification in a little more detail. 

1. Switched WAN 

In a switched WAN network, multiple component LANs are connected via a shared networking infrastructure. A WAN switching exchange at the center governs how network resources are distributed across locations, in conjunction with the network appliances at each location. Switched WAN is best suited to distributed environments where network configuration requirements are largely homogenous. 

2. Point-to-point WAN 

In a point-to-point WAN environment, two LANs or end nodes are connected through a dedicated and secure leased line. Old school broadband networks using dial-up technology are a good example of point-to-point WAN. Modern enterprises also use this type of WAN to enable secure and customized network performance between two locations. Each of the two end nodes is further connected to multiple devices to create a local area network. 

You can also classify WAN into five types based on its underlying technology. These are: 

• Dedicated internet access (DIA) WAN: The carrier offers the same upload and download speed and guaranteed bandwidth. 
• Broadband internet WAN: This is a consumer-grade WAN environment that provides you with asymmetrical connections – i.e., download speed is typically higher than upload speed. This type of WAN is significantly more affordable than DIA WAN but does not guarantee reliable performance. 
• Voice over LTE (VoLTE) WAN: This type of WAN environment uses 4G or 5G technology to achieve connectivity even in remote locations. However, VoLTE WAN is typically metered, and you may be charged for consumption beyond a threshold. 
• MPLS WAN: This is the oldest type of WAN in use, and it essentially extends the existing LAN environment by laying site-to-site leased lines. 
• Software-defined (SD) WAN: This is a newly emerging type of WAN where a software platform is used to manage the entire network infrastructure, replacing most of your physical appliances. You can leverage a mix of different WAN connections and optimize bandwidth flow to balance cost with performance. 

Now that you know about the different types of WAN available to enterprises let’s deep dive into its core architecture. 

See More: Intent-Based Networking: What Is It and Will It Usher an Era of Agile Networks?

Key Architectural Components of WAN

The exact design of your WAN architecture will vary based on your business requirements and the type(s) of WAN in use. However, seven architectural components are essential for WAN implementation: 

Architectural Components of WAN

1. End devices

End devices are computing systems that are being connected through wide area network technology. These can range from user-facing interfaces like mobile devices, PCs, and industry-specific workstations to servers, data centers, and mainframes. End devices in one location are grouped into a LAN, and multiplier LANs are connected via WAN. The location and nature of the end device will help you determine the type of WAN technology to use. 

2. Customer premises equipment (CPE)

While most of the networking infrastructure used in WAN is owned by the carrier or service provider, CPE is owned by the enterprise and sits in your local environment. Different types of CPE are used to improve network performance and align the infrastructure with business needs. Examples of CPE include telephones, routers located in your office space, physical firewall appliances, virtual private network (VPN) hardware devices, and set-top boxes. Keep in mind that the WAN provider may assist you with CPE management and maintenance as well. 

3. Access points and routers

While access points and routers technically fall under CPE (as they are located within the LAN environment), they deserve special mention as indispensable architectural components of WAN. a router is your core LAN hub and manages data flow to and from your end devices. Modern routers also have built-in modems, which means that they can receive connectivity signals from the external network and relay it to end devices from a singular appliance. 

Access points are a staple of enterprise WAN architecture. It lets you extend the wireless coverage of your local area network so that you can group hundreds or thousands of end devices spread across a massive office campus into a single LAN. Once again,  access points and routers are both considered to be CPE. 

3. Network switches

Network switches (also part of your CPE) sit between your access points and routers and the end devices to which they are connected. They forward data packets coming through the external network and regulate how they are distributed across your various end devices. Switches can exist in multiple layers, and their job is to ensure that every device gets the bandwidth it requires for optimal performance. In an SD-WAN environment, the network switch system exists purely in software format so that you can programmatically configure how switches are turned on/off and managed. 

4. Local area network (LAN)

LAN is a key architectural component of a wide area network. All the components we discussed so far (end devices, CPE, access points, routers, and network switches) are part of your local area network environment. LAN can comprise just two devices in a consumer-grade use case – a mobile or laptop and the router + modem combination. On the other hand, an average office campus will have thousands of end devices and well-articulated network topology of CPE, access points, routers, switches, etc., which together form LAN. WAN is used to connect two or more LAN environments. 

5. Connecting media

The connecting media carries data packets in a WAN mesh architecture to and from different LAN components. There is a wide variety of media to choose from when setting up your WAN, including traditional MPLS lines, fiber optic cables, the cellular (3G, 4G, or 5G) spectrum, and satellite connectivity. A complex enterprise WAN architecture will rely on multiple media to connect end devices with the internet. For example, MPLS lines are best suited to LAN environments in close proximity, 4G enables high-speed connections in remote environments, and satellite connectivity is used for security-sensitive applications. 

6. Metropolitan area network (MAN) – optional

A metropolitan area network or MAN is an optional component of WAN architecture. Instead of directly connecting two or more LAN environments, you can choose to connect LANs within a relatively small radius using a MAN. Multiple MANs, then, are interlinked to form a wide area network or WAN. A metropolitan area network may be implemented in public sector use cases, where it is necessary to connect schools, colleges, hospitals, and other institutions in the same city using a single secure network. 

7. Unified management portal – optional, but recommended

A unified WAN management portal is becoming increasingly commonplace in enterprise WAN implementations. This is because WAN can be difficult to orchestrate and manage, with each LAN hub responsible for network management for its own location. A unified portal (preferably on the cloud) gives you holistic visibility into network operations and allows you to configure bandwidth capacity, speed, performance, and security mechanisms. One of the biggest advantages of SD-WAN is that it makes it easier to deploy WAN management portals and streamline network governance for the enterprise.

See More: Why Managed Wi-Fi Services Meet the Needs of  Small and Medium-Sized Organizations

Top 10 Best Practices for Implementing and Managing Wide Area Network (WAN) in 2021

In 2020, WAN technology comprised a $75.9 billion market, according to TeleGeography. Most of this is due to sustained MPLS demand, along with a sharp increase in the SD-WAN segment. As enterprises look at refurbishing their network environment in the next few years, here are 10 best practices to remember. 

1. Configure your wide area network for wireless connectivity 

Enterprise connectivity must support wireless connections as a productivity staple. Employees working a hybrid model will bring their laptops and smartphones to work, which requires a wireless WAN connection. Open office layouts without fixed desks and conferencing spaces also need wireless connectivity. IoT is another use case that relies on powerful wireless WAN infrastructure. You can achieve this by installing a cloud-based WAN management platform and strategically placing access points. 

2. Deploy a “hardware-lite” WAN architecture 

As your digital maturity increases (particularly in response to the pandemic), there is a very real risk of hardware sprawl. For example, you can add on new access points to support a change in your office layout. New hardware appliances may be purchased to strengthen network security. After some time, it becomes difficult to maintain an inventory of your WAN architecture, leading to bloated costs and inefficiency. You can address this by keeping the hardware components of your WAN architecture to a bare minimum and opting for software-based components instead. 

3. Carefully assess your options before choosing a WAN provider 

There are several options when it comes to choosing a partner for WAN implementation. You could work directly with the supplier of WAN hardware appliances and set up your own environment. There are managed WAN providers like Verizon, as previously discussed. Your existing telecom carrier may also have a WAN offering. The decision will depend on the availability of in-house resources and WAN type. 

4. Set up multiple layers of failsafe mechanisms 

Since network connectivity forms the backbone of an enterprise, you cannot afford extended downtime or poor performance. That’s why failsafe mechanisms and backup WAN infrastructure are as important as your primary connection. Ideally, the failsafe mechanism should have a different underlying technology than the primary WAN – for example, you can have an SD-WAN set up as a backup to MPLS and a 4G network to fall back on in case both fail. 

5. Leverage SD-WAN to make your network carrier-agnostic 

It is a good idea to gradually decrease your dependence on a single telecom carrier and make your enterprise network infrastructure carrier agnostic. This will ensure that if one carrier fails to perform as per expectations (due to adverse market conditions, regulatory changes, acts of God, etc.), you are equipped to scale your network without interrupting business continuity quickly. 

6. Develop a WAN security strategy 

By its very definition, WAN exposes your local area network to wider access. This can introduce new security vulnerabilities. Begin by assessing the risk level of each component LAN environment, its devices, and applications. Next, strengthen localized security measures, configure your unified portal to be accessible by only authorized users, and implement network access control. 

7. Take advantage of WAN optimization technologies 

There are several WAN optimization technologies that can help you extract more value from your network investments. This includes data compression, which shrinks network packets to lower bandwidth consumption, and data deduplication. You can also locally deploy tools like Wi-Fi analyzers to distribute available resources among end devices more optimally. 

8. Configure your WAN setup to support multi-cloud environments 

A surge in cloud applications is among the top technology trends of 2020-2021, and your WAN setup must evolve in tandem. It is likely that you are using multiple cloud solutions for discrete use cases, which can strain your network infrastructure and impact performance. The WAN architecture must be designed to allocate precise bandwidth volumes and ensure performance thresholds depending on the nature of the application and the cloud environment where it is housed. 

9. Find the right balance between leased lines and software-defined connectivity 

SD-WAN is more affordable than leased lines, but the latter typically provides more reliable and consistent performance. It is advisable to reserve leased line-based WAN for your high-priority applications and mission-critical workflows. SD-WAN can be used to take care of ancillary connectivity use cases like guest access, routine file backup, etc. 

10. Review your WAN architecture regularly and upgrade with emerging solutions 

New network innovations emerge every day that can transform how you connect your enterprise, design the WAN architecture, and orchestrate performance. For example, Juniper and Intel now offer artificial intelligence (AI) enabled WAN solutions that can intelligently automate network processes and provisioning. You can also gain from advanced WAN analytics, a blend of hardware and SD-WAN architecture, and a host of other innovations. Review your existing setup once a year, inventory any sprawl or retirement-ready components, and upgrade with emerging solutions. 

See More: How SD-WAN Is Simplifying and Accelerating Multi-Cloud Adoption

Takeaway

A wide area network or WAN is a critical cog in your IT infrastructure, which is why organizations are investing heavily in WAN technology and updates. Recently, the U.S. defense information systems agency entered into a potentially $495 million worth deal with Verizon to implement large-scale WAN services over the next ten years. By designing a WAN architecture that’s in tune with your business needs and keeping in mind the ten best practices we discussed, you can make the most of your network investments. A strong WAN environment can support business processes, drive scalability, and eventually lead to continued growth. 

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