Author: Neftaly Malatjie

The main components for a WAN are routers, switches and modems. These components are described below.

• CPE – Devices on the subscriber premises are called customer premises equipment (CPE). 
  The subscriber owns the CPE or leases the CPE from the service provider. A copper or fiber cable connects the CPE to the service provider’s nearest exchange or central office. This cabling is often called the local loop, or “last-mile”.

• DTE/DCE – Devices that put data on the local loop are called data circuit-terminating equipment, or data communications equipment (DCE). The customer devices that pass the data to the DCE are called data terminal equipment (DTE). The DCE primarily provides an interface for the DTE into the communication link on the WAN

• Router – An electronic device that connects a local area network (LAN) to a wide area network (WAN) and handles the task of routing messages between the two networks. Operates at layer 3, and makes decisions using IP addresses.

• Switch – A switch is a network device that selects a path or circuit for sending a unit of data to its next destination. Operates at layer 2, and uses MAC addresses to send data to correct destination.

• Modem – Short for modulator/demodulator, a modem enables a computer to communicate with other computers over telephone lines. Operates at layer 1, where signals are converted from digital to analogue and vice versa for transmission and receiving.

• Terminator – device connected to one end of a bus or cable that absorbs signals. Terminators prevent signal reflection, which can produce interference that causes signal loss. Most communication systems such as networks and computer buses require some form of termination at the ends of the data path, although this is often provided internally by the devices at the ends of the data path.

• Network Cable- To connect together different devices to make up a network, you need cables. Cables are still used in most networks, rather than using only wireless, because they can carry much more data per second, and are more secure (less open to hacking).

• Hub- A hub is a device that connects a number of computers together to make a LAN.  The typical use of a hub is at the centre of a star network (or as part of a hybrid network) – the hub has cables plugged into it from each computer.

• Proxy Server- A proxy server is a computer setup to share a resource, usually an Internet connection. Other computers can request a web page via the proxy server. The proxy server will then get the page using its Internet connection, and pass it back to the computer who asked for it. Proxy servers are often used instead of router since additional software can be easily installed on the computer such as anti-virus, web filtering etc.

WAN networks are much more expensive than home or corporate intranets.

WANs that cross international and other territorial boundaries fall under different legal jurisdictions. Disputes can arise between governments over ownership rights and network usage restrictions.

Global WANs require the use of undersea network cables to communicate across continents. Undersea cables are subject to sabotage and also unintentional breaks from ships and weather conditions. Compared to underground land lines, undersea cables tend to take much longer and cost much more to repair.

Many businesses started using leased line WANs in the mid-1990s as the web and internet exploded in popularity. T1 and T3 lines are often used to support MPLS or internet VPN communications.

Long-distance, point-to-point Ethernet links can also be used to build dedicated wide area networks. While much more expensive than internet VPNs or MPLS solutions, private Ethernet WANs offer very high performance, with links typically rated at 1 Gbps compared to the 45 Mbps of a traditional T1.

If a WAN combines two or more connection types, like if it uses MPLS circuits as well as T3 lines, it can be considered a hybrid WAN. These are useful if the organization wants to provide a cost-effective method to connect their branches together but also have a faster method of transferring important data if needed.

A WAN (wide area network) is a communications network that spans a large geographic area such as across cities, states, or countries. They can be private to connect parts of a business or they can be more public to connect smaller networks together.

The easiest way to understand what a WAN is to think of the internet as a whole, which is the world’s largest WAN. The internet is a WAN because through the use of ISPs, it connects lots of smaller local area networks (LANs) or metro area networks (MANs).

On a smaller scale, a business may have a WAN that’s comprised of cloud services, its headquarters, and smaller branch offices. The WAN in this case would be used to connect all of those sections of the business together.

No matter what the WAN joins together or how far apart the networks are, the end result is always intended to allow different smaller networks from different locations to communicate with one another.

Note: The acronym WAN is sometimes used to describe a wireless area network, though it’s most often abbreviated as WLAN.

How WANs Are Connected

Since WANs, by definition, cover a larger distance than LANs, it makes sense to connect the various parts of the WAN using a virtual private network (VPN). This provides protected communications between sites, which is necessary given that the data transfers are happening over the internet.

Although VPNs provide reasonable levels of security for business uses, a public internet connection does not always provide the predictable levels of performance that a dedicated WAN link can.

This is why fibre optic cables are sometimes used to facilitate communicate between the WAN links.

X.25, Frame Relay, and MPLS

Since the 1970s, many WANs were built using a technology standard called X.25. These types of networks supported automated teller machines, credit card transaction systems, and some of the early online information services such as CompuServe.

Older X.25 networks ran using 56 Kbps dial-up modem connections.

Frame Relay technology was created to simplify X.25 protocols and provide a less expensive solution for wide area networks that needed to run at higher speeds. Frame Relay became a popular choice for telecommunications companies in the United States during the 1990s, particularly AT&T.

Multiprotocol Label Switching (MPLS) was built to replace Frame Relay by improving protocol support for handling voice and video traffic in addition to normal data traffic. The Quality of Service (QoS) features of MPLS were key to its success. So-called “triple play” network services built on MPLS increased in popularity during the 2000s and eventually replaced Frame Relay.

Network Interface card, one of the main computer network components, comes with different speeds, 10Mbps, 100Mbps, and 1000Mbps, so on. Recent standard network cards built with Gigabit (1000Mbps) connection speed. It also supports to connect slower speeds such as 10Mbps and 100Mbps. However, the speed of the card depends on your LAN speed.

For example, if you have a switch that supports up to 100Mbps, your NIC will also transfer a data with this same speed even though your computer NIC has still the capability to transfer data at 1000Mbps (1Gbps). In modern computers, network adapter is integrated with a computer motherboard. However if you want advanced and fast Ethernet card, you may buy and install on your computer using the PCI slot found on the motherboard (desktop) and ExpressCard slots on laptop .