As a result of technological advances, the world has been altered a great deal in the last few decades. Rather than merely cope with local or provincial issues, most enterprises now have to contend with international markets and logistics. International and large-scale business companies have installations sprawling throughout the country or across the world. Thus, a means of sustaining a high-speed, safe, and dependable communications framework wherever their facilities are is of immense importance. This has led to the extensive use of wide-area networks (WAN), which enables a business outfit with a technique to spread out its private network further than its immediate geographic reach. The WAN or the Wide Area Network is a computer network that encompasses an extensive geographic area, or in other words, it is a network with communications linkages across national precincts, metropolitan or regional. The WAN has noticeable benefits as contrasted against a public network in terms of consistency, performance, and protection.
A WAN primarily operates at the OSI model networking framework in the context of Network Layer, Data Link Layer, and Physical Layer. To install a WAN, the choice of some essential devices and communication media are crucial. The primary equipment required are switches, modems, routers, repeaters, CSU/DSU, and access servers, in addition to coaxial cable and fiber optics which are required for data transmission.
At present, there are quite a few WAN Connectivity methods, among which the most widely used ones are Leased Line, Circuit Switching, Packet Switching, and Cell Relay. In a Leased Line, P2P connections are established between two nodes which in this case are two separate LANs. It is the most secure means of transmission but at the same time is expensive. A circuit-switched link is created amongst two switches using the telephonic infrastructure and holds back the entire bandwidth of that connection, i.e., irrespective of the type of data being transmitted, the bandwidth is engaged and cannot be used by other devices. This leads to a wastage of bandwidth. Given that circuit-switched communications results in inefficient bandwidth usage, they do not constitute a viable connection. In a packet switching technique, the bandwidth is shared across a network by means of virtual circuits. Various virtual circuits can utilize the same physical channel at different instances. Switches spread across the network manage the use of the physical link by the virtual circuits at a particular instance. The Cell Relay procedure is analogous to the packet switching method, except that it uses fixed-length cells in place of packets of variable dimensions. It is used for simultaneous transmission of voice and data, but overheads can be a major issue in this option.
Dialup services provide cost-effective schemes for connectivity using WANs. The most widespread dialup implementations are DDR or dial-on-demand routing and dial backup. DDR is a system by which a router is capable of dynamically opening a call on a switched circuit when data has to be transmitted. Here, the router is set up to start the call based on certain conditions being met. After the connection is established, traffic is transmitted over the line. An idle timer is set in the router that instructs dropping of the connection after a certain idle period. Dial backup is one more technique for setting up DDR. In dial backup, the switched circuit is employed to offer backup service for an additional form of circuit. The router is configured in a manner that initiates the dial backup channel when a malfunction is identified on the primary circuit. This sustains the WAN connection awaiting the refurbishment of the primary circuit.
Thus, for setting up an efficient communication network to establish connectivity between the Cleveland and Pittsburgh facilities, a Packet-switched network is the most viable option with a dial backup connection. This method is chosen over the others because the packet switching technique is more efficient in its bandwidth usage and is also relatively cheaper to install and maintain. The Dial backup mode enhances the reliability of the network, and thus the combination would be a useful solution for the connectivity needs of the organization.