Networking is at the center of all information sharing and Internet activities, and most homes and businesses have some sort of networking technology used for internet access and for enabling the business communications and functions.
However, many people struggle with some of the fundamental concepts involved in computer networking. Both Local-Area Networks, or LANs, and Wide-Area Networks, or WANs, play valuable roles in networking and are two of the most common types of computer networks.
In this article we will be discussing each network type (LAN vs WAN) and discuss the differences between the two topologies.
What is a LAN?
The collection of multiple computers and other networked devices (such as network printers, laptops, servers etc) which are all connected on the same local network forms a Local Area Network (LAN).
The key concept to LANs is that they cover a relatively small region, typically a home, business office or building.
Communication over LANs is normally done by connecting computers and network equipment to a network switch (Ethernet switch) as shown on the diagram above.
Each computer and network equipment has an IP address assigned to it, which is unique to each device on the network. Usually, private IP addresses are assigned in LAN networks.
Although each device can be given an IP address manually, it’s more common to rely on a service called DHCP, which automatically gives connected devices an IP address that doesn’t conflict with other devices on the LAN itself.
The main infrastructure of most LANs contains a network switch and also a network router (see figure above). In an enterprise LAN network, usually the network switch is different from the network router. On the other hand, in a small LAN like a home network, the router includes also a network switch on the same device.
Most modern home routers have Ethernet ports (switch ports) along with Wi-Fi connection options, which make it easier to connect devices. The term WLAN stands for wireless LAN, and it falls into the LAN category.
Once devices are on LANs, they can typically see each other over the network. By opening networking ports on computers and entering the right IP address, devices can connect through various protocols including FTP for file transfers, SSH for connecting to a remote command line, SFTP for file transfer with safer encryption, RDP for Microsoft Remote Desktop etc.
LANs often serve as the gateway to the internet for local users. A centralized device, typically a router, serves as the part of the network directly visible to the internet, and all internet traffic is sent and received through it.
What is a WAN?
At first glance, WANs seem to just be larger LANs, although there are some important differences.
The Internet itself is typically viewed as a WAN, and, like many WANs, its infrastructure is far more complicated than LANs.
LANs typically use only a small portion of potential IP addresses, making it easy for devices to connect.
WANs, which often have hundreds or more devices connected, need to use more address space, potentially making communication more complicated. Usually, public IP addresses are used in WANs compared to LANs.
Furthermore, WANs often contain different subnetworks, and some of them might need differing types of security. Servers connected to a WAN, for example, need to be properly secured to prevent unauthorized access (usually using a firewall).
In general, WANs are viewed as a collection of connected LANs. WANs often provide connectivity between these smaller networks, allowing devices to communicate with each other across the entire WAN. Usually, Internet Service Providers (ISPs) are the main players used to create and implement a WAN.
Exactly how devices connect is determined by the centralized infrastructure used in a WAN, which tends to be more complex than infrastructure used for even the largest LANs.
In many cases, WANs rely on large scale ISP networks than can handle the large and complex routing needed to direct traffic properly. Like LANs, however, WANs often offer connectivity to the broader internet.
Differences Between LAN and WAN
LANs generally rely on basic IP routing for all of their traffic. A LAN is typically built over an Ethernet network and if the devices belong to the same Layer 3 network subnet, then packets are just switched, using a Layer2 switch, from one host to another.
WANs often employee larger-scale routing protocols in order to route packets effectively. Some routing protocols used in WANs include BGP, OSPF etc.
Furthermore, nearly all LANs are run by a single entity, such as a family or a business. WANs, on the other hand, are often run by a collection of entities, such as city departments or companies operating in a business network. However, some WANs, such as those run by universities, may have centralized ownership.
WANs and LANs differ based on their geographical distribution more than the number of clients connected.
A LAN used to deliver internet access to a residential skyscraper, for example, might have more connections than one used in a WAN that connects LANs spread across the globe. The size and scope of the latter, however, means it falls into the WAN category.
LANs offer greater speed between clients than WANs, in part due to their simplified and shorter networking distance, and also mainly due to the communication technology which is prevalent in LANs (that is, Ethernet communication).
It’s worth noting that it’s not always easy to determine if a particular network qualifies as a LAN or a WAN, and some modern networks might have features that seem to fall into both categories.
Comparison Table Between LAN and WAN
|Main Definition||LAN computer network usually covers small geographic area such as home, small office, building, campus. Mainly based on Ethernet technology.||WAN network covers large geographic area such as between cities or countries. Usually, a WAN consists of many LANs.|
|Speed (data bandwidth)||Larger than WANs (1 Gbps, 10Gbps and above)||Lower speed than LAN (typically 50, 100, 150 Mbps)|
|Geographical Area||Limited (usually within the same building or same campus)||Large area (between countries or cities)|
|Connection types||Usually Ethernet cables (Cat5, Cat6) or Fiber Optic or WiFi||Usually fiber optic or other WAN technologies such as MPLS, ATM, ADSL, Cable, VPN etc)|
|Administration||Usually owned and operated by a single entity or organization.||Usually managed and operated by larger entities or businesses (e.g ISP, large corporations etc).
A WAN typically includes many smaller LANs.
|Cost (both maintenance and operational)||Cheap||Expensive|
|Network Equipment||Usually consist of Network Switch and Router (and maybe a small firewall)||Many Network Switches, Routers, Firewalls, WAN termination devices (such as DSLAM, Fiber Optics etc).|
|Examples||Home network, business network in the same building.||Internet, ISP networks.|
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