Wide Area Network or WAN is a private telecommunications network that is geographically distributed. A WAN typically interconnects numerous Local Area Networks (LANs).
What is LAN?
A collection of network devices and computers connected to one another comprise a LAN. They are characteristically within a shorter geographical distance, as compared to WAN.
WAN and LAN are both availed by organizations or businesses. The most suited alternative is selected based upon the entity’s requirements.
A WAN may bring in connectivity in between a company’s headquarters, branch offices, and other facilities. Multifunction devices such as routers are used to connect a LAN to a WAN. This lets users share access to different, centrally located resources, such as services, applications, and data. Hence the need to install firewalls, application servers, and related resources at multiple locations is done away with.
While LAN is characteristically restricted to a common geographic location, WAN is not. In general, LAN is set up in a particular geographical area and is connected to WAN.
Virtual Private Network (VPN)
Connectivity and security amongst segregated WAN sites are enabled with the use of a VPN. VPNs are of different kinds and used based upon use cases.
IPsec (Internet Protocol Security) VPN
For site-to-site connections that are continuously open, IPsec VPN is more frequently used. The connection between branch offices and headquarters is one example of such connections.
SSL (Secure Socket Layer) VPN
Similarly, for facilitating remote access for individual users, SSL VPN comes by as the preferred option. Data transmitted by users through WAN is encrypted in this case, adding to its security.
Direct fiber-optic links
Alternately to connect different sites over WAN, direct fiber-optic links are used. They typically deliver higher performance and are more secure and reliable as compared to other VPNs. But they come by as a more expensive alternative to purchase and use as compared to other kinds of VPN.
Wired and Wireless WAN connections
A WAN connection may be of either type, wired or wireless. Several organizations prefer to go for a wired network connection, but wireless WAN technologies are gaining more traction by the day.
A WAN infrastructure could be privately owned. A third-party service provider may lease the WAN infrastructure as a service, and This arrangement is known as leased as a service. Some examples of such third party service providers are a cable company, internet service provider, or a private IP network operator.
Hybrid WANs use a combination of public and private network services.
Software-defined WAN (SD-WAN)
SD-WAN makes hybrid WAN architectures easier to manage, operate, and deploy for enterprises. This is achieved with the use of a combination of customer premise equipment (CPE), software platforms, on-site SD-WAN devices, network overlays, application-level policies, and virtualization.
SD-WANs are an aggregation of numerous private and public WAN links. An automatic path for traffic is automatically selected. It is based upon real-time conditions. Earlier, however, network managers were required to reconfigure the network manually, to route the traffic over multiple routes.
Enterprise WANs come across performance issues owing to bandwidth and latency constraints. Appliances for WAN optimization use several techniques to counter WAN optimization issues. These techniques include local caching, traffic shaping, protocol optimization, compression, and de-duplication.
Application performance control moves to a new level, as provided by SD-WAN CPE or platforms. This is achieved over lower-cost bandwidth connections and is more reliable. It is often implemented as commercial internet services.
Let us now take a look at the advantages and disadvantages of WAN:
- Using leased lines over broadband connections allows an increase of bandwidth
- Security and a centralized infrastructure
- Coverage across a larger geographical area
- Need for firewalls and antivirus software
- Set up costs are high
- A possibility of security gaps exist