What is a WAN (Wide Area Network)? Explained

Wide Area Network or WAN is a private telecommunication network that is geographically distributed. WANs typically connect multiple local area networks (LANs).

What is a LAN?

LAN includes a collection of interconnected network devices and computers. They are typically within geographical distances compared to WANs.

Both WAN and LAN are used by organizations or businesses. The most appropriate option is selected based on the needs of the entity.

WAN can bring connectivity between company headquarters, branch offices and other facilities. Multifunction devices like routers are used to connect LAN to WAN. This allows users to share access to a variety of centrally located resources, such as services, applications, and data. This eliminates the need to install firewalls, application servers and related resources in multiple locations.

While LAN is typically limited to a general geographic location, WAN is not. Typically, a LAN is set in a specific geographic area and is connected to a WAN.

Virtual Private Network (VPN)

Connectivity and security between split WAN sites is enabled using VPN. VPNs are of different types and are used depending on the use case.

IPsec (Internet Protocol Security) VPN

For site-to-site connections that are constantly open, IPsec VPNs are used more often. The connection between the branch offices and the headquarters is an example of such a connection.

SSL (Secure Socket Layer) VPN

Similarly, to facilitate remote access for individual users, SSL VPN comes as an option of choice. Data transmitted by users via WAN is encrypted in this case, which enhances its security.

Direct fiber-optic links

Alternatively, direct fiber-optic links are used to connect different sites over the WAN. They generally offer high performance and are more secure and reliable than other VPNs. But they come as a more expensive option to buy and use than other types of VPNs.

Wired and wireless WAN connections

The WAN connection can be of any type wired or wireless. Many organizations prefer to go for a wired network connection, but wireless WAN technologies are gaining more traction day by day.

WAN infrastructure may be privately owned. A third-party service provider may lease WAN infrastructure as a service and this arrangement is known as a service lease. Some examples of such third party service providers are cable companies, Internet service providers or private IP network operators.

The hybrid WAN uses a combination of public and private network services.

Software-defined WAN (SD-WAN)

SD-WAN Hybrid makes WAN architecture easy to manage, operate, and deploy for enterprises. This is achieved through the use of a combination of customer premium equipment (CPE), software platforms, on-site SD-WAN devices, network overlays, application-level policy and virtualization.

SD-WAN is an aggregation of numerous private and public WAN links. Automatic route for traffic is selected automatically. It is based on real-time situations. Previously, however, network managers needed to manually reconfigure the network so that traffic could be routed on multiple routes.

WAN optimization

Enterprise WAN encounters performance issues due to bandwidth and latency constraints. Devices for WAN optimization use a variety of technologies to address WAN optimization issues. These techniques include local caching, traffic parameters, protocol optimization, compression and de-duplication.

Application performance control provided by the SD-WAN CPE or Platform goes to a new level. This is achieved on low cost bandwidth connections and is more reliable. It is often applied as commercial internet services.

Let’s take a look at the advantages and disadvantages of WAN:

Advantages:
  • Use of leased lines on broadband connections allows increase in bandwidth
  • Security and central infrastructure
  • Coverage over a large geographical area
Disadvantages:
  • Requires firewall and antivirus software
  • Set up costs are high
  • There are likely to be gaps in security

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