tailieunhanh - Network+ Certification (Outline) - Chapter 2: Network hardware

Chapter summary: The network topology is the pattern used to connect computers and other devices with the cable or other network medium; the three primary LAN topologies are bus, star, and ring; UTP cable in the star topology is the most common network medium used today; a network interface adapter provides the interface that enables a computer to connect to a network; the network interface adapter and its driver implement the data-link layer protocol on the computer; hubs are devices that connect computers on a star or ring network. | Chapter 2 Network Hardware 1 Chapter Overview A. Network Cables B. Network Interface Adapters C. Network Hubs Chapter 2 Lesson 1 Network Cables 2 1. Cable Topologies 3 A. Bus topology 1. Uses coaxial cable 2. Used by thick and thin Ethernet networks 3. The nodes are connected in series. 4. A bus network must be terminated at both ends. 5. The signals transmitted by a computer travel in both directions. 6. Cable faults affect the entire network. a. A cable fault breaks the network in two preventing signals from passing from one segment to the other. b. The lack of termination on the broken ends further degrades performance. 4 B. Star topology 1. Most common topology used in LANs today a. Used primarily with Ethernet 2. Uses various cable types especially unshielded twisted pair UTP 3. Requires a hub or concentrator 4. Computers are connected to the hub not to each other. 5. Cable faults affect only one computer. 6. The hub is a central point of failure but hub faults are rare. 5 6 C. Ring topology 1. A ring network is like a bus network with the two ends connected. 2. Used primarily by Token Ring and Fiber Distributed Data Interface FDDI protocols 3. Most but not all ring networks are logical rings. a. The physical network takes the form of a star. 4. Most ring networks use the token passing Media Access Control MAC mechanism. 5. In a physical ring a cable fault affects the entire network. 6. A logical ring is physically cabled as a star and has the fault tolerance of a star network. 7. FDDI can use a physical ring topology or a double ring topology. 8. Double ring topology a. Consists of two separate rings with traffic flowing in opposite 7 D. directions b. Requires a computer to have a network interface with two jacks c. If a cable fails traffic is shunted to the other ring. Hierarchical star topology 8 9 10 E. F. 1. Also known as a branching tree network 2. Expands a star network beyond a single hub Mesh topology 1. Mesh LANs a. Mesh LANs are generally .

• Quản trị mạng
• Network+ Certification
• Networking technologies
• Open Systems Interconnection
• Computer networking
• Network hardware
• Cable topologies