 traffic. See Chapter 1 for a discussion of fiber and copper cabling. Copper cabling is used most often to connect nodes to LANs. (The term devices are used synonymously with nodes.) Wireless of course is used for Wi-Fi. See the section on Wi-Fi in Chapter 7, "Mobile and Wi-Fi Networks." Increased Bandwidth Needs on LANs A number of factors are causing the amount of traffic on local area network to increase exponentially. These www.TechnicalPDF.com include increasing amounts of data-intensive centralized computing and requirements for additional storage. Another factor is the growing dependence on accessing content in the cloud. The staff's cloud traffic transits LANs to reach databases located in the cloud and in companies' data centers. And to a greater extent than ever before, video traffic streamed and downloaded from the cloud, the Internet, and from on-site videoconferences is adding to LAN congestion and the need for larger pipes. Other factors adding to LAN congestion are: Large graphics file attachments such as PowerPoint files. Daily backups to databases of entire corporate files. Web downloads of long, continuous streams of images, audio, and video files. Access by remote and local employees to applications and personal files on centralized servers and storage devices. Web access, during which users typically have four or more windows open concurrently. Each open web page is a session, an open communication with packets traveling between the user and the Internet. Here's a quote from an IT Director at a university: "We never have enough capacity on our local network or storage space in our storage area network." Protocols for Communications in LANs All devices connected to LANs use network protocols to access the LAN. They communicate with other devices and applications, which might be located on the same floor, on another floor, in another building, or even on an organization's LAN located on another continent. By providing a uniform way to communicate, LANs simplify the process of linking devices, ap