What is a WAN? | Pros, Cons and Examples | NBC

What is a WAN? Pros, Cons and Examples

July 24, 2023

what is a wan

This article on wide-area networks (WAN) includes helpful definitions, examples, answers to frequently asked questions, and more. Read on to learn what a WAN is, in addition to the advantages and disadvantages of WANs.

What is a WAN?

A wide-area network (WAN) is a technology that spans several locations in a geographic area, connecting homes, offices, cloud applications and the like.

WANs are made up of multiple networks, including local area networks (LAN), that communicate with one another. Put simply, a WAN is a network of networks, the largest of which is the Internet, which constitutes multiple international networks 

What’s the purpose of a WAN connection?

WANs are essential in an increasingly digital world and serve an array of functions necessary for individuals and corporations. For example, we use WANs to:

WAN technology is particularly helpful to businesses and organisations, enabling them to access information quickly and securely. 

WAN: A History

Below, we’ve included a brief overview of how wide-area networking began:

What are the different types of WAN technologies?

There are a variety of WAN technologies, including:

Packet switching

Packet switching is a means of data transmission whereby messages are compartmentalised into several parts (known as spackets). Each packet is sent in the most optimal way – whether this be independently, in triplicate, or any other route – before they’re reassembled at the destination. Each packet features a piece part (known as the payload), as well as an identifying header which states the destination and reassembly information. Sending packets in triplicate is a reliable way to check for packet corruption, while each packet is checked to see that at least two copies match. If this isn’t the case, a request is made for the packet to be re-sent.

TCP/IP protocol suite

TCP/IP is a suite of communication protocols that allow interconnection between network devices on the Internet and other networks.


Routers are devices used to interconnect local area networks (LANs) to form a WAN. A router’s IP address determines where to forward packets.

Overlay network

Overlay networks refer to virtual computer networks layered on top of another network. Overlay networks often function to support applications or features that an underlying network can’t facilitate.

Packet over SONET/SDH

Packet over SONET/SDH (POS) is a communications protocol used to transmit packets over SDH (Synchronous Digital Hierarchy) or SONET (Synchronous Optical Networking).

Multiprotocol Label Switching (MPLS)

Multiprotocol Label Switching (MPLS) is a technology that routes traffic using the shortest path based on labels, as opposed to network addresses. It functions to handle forwarding over private WANs and has a positive impact on traffic speeds.


Asynchronous Transfer Mode (ATM) is a telecommunications standard for digital transmission of various types of traffic. While it’s been surpassed by IP-based technologies in the modern day, ATM was a common switching technique in early data networks. The method utilises synchronous time-division multiplexing to codify data into small cells; this is opposed to modern, IP-based technology, which utilises variable packet sizes.

Frame relay

Frame relay uses packet-switching technology to transmit data between LANs or the endpoints of a WAN. The method involves breaking data into smaller packets which are then transmitted through a shared frame relay network. Once the packets arrive at the destination, they’re reassembled.

WAN advantages

WAN advantages include:

WAN disadvantages

WAN disadvantages include:

WAN examples

Below, we’ve included a few examples of WANs to help illustrate what they are and how they work:

Enterprise or organisation

In enterprises, WANs may be used to ensure all branch offices are interconnected or to connect remote employees to the organisation’s main office. Universities may utilise WANs so students can access research resources or library databases.


Baks may utilise a WAN for its branches and ATM machines. WANs can connect branches in multiple secure locations, benefitting both employees and users.

The Internet

The internet is often described as the world’s largest WAN, for it’s a network of networks that connects devices and computers all over the world.

What’s the difference between a WAN and a LAN?

WANs and LANs (local area networks) serve different purposes and cover different areas. LANs cover relatively small areas, such as a home or office building, connecting devices in fairly close proximity to one another. WANs, on the other hand, cover large geographical areas and connect multiple LANs. 

Ultimately, WANs facilitate communication and connection over longer distances, whereas LANs are designed for sharing within a specific location.

More helpful articles:

Frequently asked questions

What is a WAN router?

Also referred to as edge routers or border routers, WAN routers route data packets between WAN locations, providing organisations access to a carrier network. There are a variety of WAN protocols, including:

What is an SD-WAN?

A software-defined Wide Area Network (SD-WAN) is a virtual WAN architecture that connects and extends networks over vast geographical distances. SD-WANs enable businesses to utilise an array of transport services – such as MPLS, LTE, and broadband internet services – to reliably connect users to applications.

What’s the difference between WAN and SD-WAN?

The main difference between a traditional WAN and an SD-WAN is that the former offers a conventional way to manage a wider area network, whereas the latter utilises a software-defined approach. This has a number of implications, such as:

Ultimately, SD-WAN presents greater flexibility, scalability, and cost-effectiveness than traditional WANs.

What is WAN optimisation?

WAN optimisation, also known as WAN acceleration, refers to a range of techniques for improving data transfer across WANs.

It involves implementing bandwidth preservation techniques like compression, caching, data deduplication, image optimisation, and more as a remedy for network congestion and latency.

WAN optimisation is important because it streamlines network traffic and gives people access to the information they need quicker.

Share this post