1. “ Getting to Know Networks”

2. What Is a Network? n A network is a collection of computers hooked up together, usually by cables or telephone wires, for the purpose of sharing information and resources. n Commonly connected devices include personal computers (PCs), ipods, ipads, cell phones, workstations, printers, fax machines, pagers, and various data-storage devices.

3. Advantages of Networks 1. Cost-effective Resource Sharing—peripherals can be shared. 2. Streamlined Business Processes—tasks such as employee collaboration on projects and holding meetings can take less time and cost less. 3. Cheaper Sales Process—networks connect businesses to customers through the electronic storefront: a Web site allows customers to search for and order products and services. The most obvious benefit is that you can store virtually any kind of information at a central location on the network as well as access it from any connected computer. Other advantages are:

4. Advantages, Continued 4.Secure Management of Sensitive Information—the ability to protect network resources and files. Proper security features will control who will have access to sensitive data, equipment, and other resources. 5.Worldwide, Instantaneous Access to Information—you will be able to distribute critical information to many locations anywhere in the world, almost instantaneously.

5. Recent Networked Peripherals n Recently, other types of devices have become network- connectable, including interactive televisions, videophones, handheld devices (PDAs), cell phones, ipods, and navigational systems like GPS (Global Positioning Systems) and environmental control systems. n Now networked devices everywhere will provide two-way access to a vast array of resources on a global computer network through the largest network of all—the Internet. n Remember, a peripheral is any device connected to a computer that performs a specific function (for example, a printer).

6. Types of Network Stations n LAN—Local area networks operate primarily over a small area, such as an office building. The cables that hook parts of the network up together are owned by the user. n WAN—Wide area networks covers a large area, such as all the branches of a bank. It is usually connected through leased telephone lines and satellite hookups.

7. Hardware Needed 1.Network Interface Cards—an expansion board inserted into a computer so the computer can be connected to a network. 2. Networking Software—directs the communication functions, security protection, and data and peripheral sharing within a group of computers. Examples include Novell and Windows NT. 3. Networking Cabling—a bundle of wires with connectors at both ends used to link parts of a computer system.

8. What about Cables? A variety of cable types and sizes are available. Some of the cables include: n Coaxial Cabling—known as coax, it is the original network cable, much like the cable used for cable TV. The problem is that coax is expensive, stiff, has a wide diameter, and is hard to run through walls. n Twisted Pair Cabling—a commonly used cable made of two insulated intertwined wires. n Fiber Optics—hollow, strand-like cables that carry pulses of light to transmit digital information.

9. What’s Network Physical Topology? n “Network topology” refers to the layout of a network. Due to the specific nature of computer network technology, networks must be arranged in a particular way in order to work properly. These arrangements are based on the network hardware’s capabilities and the characteristics of the various modes of data transfer. Some of them include: – Ring – Bus – Star

10. What Is a Ring Topology? n Individual devices are connected to a central hub, just as they are in a star network. However, within each hub the physical connections form a ring. n Each node is dependent on each other, and information is sent in one direction. Therefore, a disruption at one node will cause the nodes after to fail.

11. What Is a Bus Topology? n A cable starts at what is called a “head end,” and branches at various points along the way. n Information is sent in two directions. However, if one node becomes interrupted, the entire system breaks down. n This topology is susceptible to bottlenecking and single-point failure.

12. What Is Star Topology? n The simplest form of the physical star topology consists of multiple cables—one for each network device—attached to a single, central connection device called a hub. All information must go to the hub first. n The actual layout of the transmission media need not form a recognizable star pattern.

13. LAN Office Layout Star Topology 10Base-T hub network administrator digital camera printer scanner workstation network server USB cable twisted-pair cable secure room

14. The Future of Wireless Technology? n Wireless topologies differ greatly from wired topologies, because the medium (radio frequencies) has different properties than wires. The principles used in creating wireless networking solutions are based on the technology currently in use with cellular telephone systems. n So far, there have been four generations of mobile technologies. The first generation is the analog cellular system, the second is digital wireless, and the third generation (3G), is often called UMTS (Universal Mobile Telecommunications System). This system is designed to be an always-on service for everything from voice to video to data transfer. Fourth generation has just been released in the iphones and other cell phones.

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