Hardware Concepts Chapter 4 Contents Explain the different

  • Slides: 30
Download presentation
Hardware Concepts Chapter 4

Hardware Concepts Chapter 4

Contents • Explain the different types of network topology • Describe the different types

Contents • Explain the different types of network topology • Describe the different types of network cabling • Describe and distinguish between the 802. 2, 802. 3, 802. 5, and 802. 11 IEEE networking standards

Topology

Topology

Topology • A topology describes how computers connect to each other

Topology • A topology describes how computers connect to each other

Types of Topologies • Bus – All computers connect via a main line, called

Types of Topologies • Bus – All computers connect via a main line, called a bus cable • Ring – All computers attach to a central ring of cable • Star – All computers connect to a central wiring point, usually a hub • Mesh – Each computer has a dedicated line to every other computer

Types of Topologies

Types of Topologies

Network Technologies • A network technology is a practical application of a topology to

Network Technologies • A network technology is a practical application of a topology to get data from one computer or network to another – Ethernet – Token Ring – FDDI-(Fiber Distributed Data Interface) is a standard for data transmission on fiber optic lines in a local area network (LAN) that can extend in range up to 200 km

Bus Topology • Ethernet was the first network technology that used the bus topology

Bus Topology • Ethernet was the first network technology that used the bus topology • Each computer on the network is connected to the single cable

Bus Topology • If there is a break in the cable, the entire network

Bus Topology • If there is a break in the cable, the entire network would stop functioning – It has no fault tolerance to survive a problem

Star Topology • Each computer is connected to a central device such as a

Star Topology • Each computer is connected to a central device such as a hub – If a cable breaks only the one computer is affected

Star Bus Topology • A star bus topology is a hybrid topology – Uses

Star Bus Topology • A star bus topology is a hybrid topology – Uses a physical star topology – Uses a logical bus topology – Most common topology used today

Token Ring Topology • Token ring uses a star ring topology – Uses a

Token Ring Topology • Token ring uses a star ring topology – Uses a physical star topology – Uses a logical ring topology – Declining in popularity

Cabling

Cabling

Coax • Coaxial cable (or coax) contains a central conductor wire, surrounded by an

Coax • Coaxial cable (or coax) contains a central conductor wire, surrounded by an insulating material, which in turn is surrounded by a braided metal shield

EMI • Electro-magnetic interference (EMI) is caused by lights, fans, copy machines, and other

EMI • Electro-magnetic interference (EMI) is caused by lights, fans, copy machines, and other devices • EMI corrupts the signal flowing through the cable • The braided shield helps to reduce the effects of EMI

Types of Coax Cable • The Ohm rating is a measure of resistance in

Types of Coax Cable • The Ohm rating is a measure of resistance in the cable and differentiates different types of coaxial cable • RG-8, RG-62, and RG-58 are used in computer networks

RG-8 • RG-8 cable is also called Thick Ethernet – Oldest type of coax

RG-8 • RG-8 cable is also called Thick Ethernet – Oldest type of coax still in use – Rated at 50 ohms – Yellow or orange/brown color

RG-62 • RG-62 cable is never installed in networks today – Was used with

RG-62 • RG-62 cable is never installed in networks today – Was used with ARCnet

RG-58 • RG-58 is also called Thin Ethernet – Still in widespread use today

RG-58 • RG-58 is also called Thin Ethernet – Still in widespread use today

Twisted Pair • Shielded Twisted Pair (STP) and Unshielded Twisted Pair (UTP) are the

Twisted Pair • Shielded Twisted Pair (STP) and Unshielded Twisted Pair (UTP) are the most common types of cabling used today – Composed of multiple pairs of wires twisted together to reduce interference from adjacent wires, called crosstalk

Shielded Twisted Pair (STP) • Twisted pairs of wires surrounded by shielding to protect

Shielded Twisted Pair (STP) • Twisted pairs of wires surrounded by shielding to protect them from EMI – Only used in older Token Ring networks

Unshielded Twisted Pair (UTP) • Most common type of cabling used in networks –

Unshielded Twisted Pair (UTP) • Most common type of cabling used in networks – Twisted pairs of wires surrounded by a plastic jacket – Inexpensive and flexible

CAT Ratings • Twisted pair cabling varies by things like the number of twists

CAT Ratings • Twisted pair cabling varies by things like the number of twists per foot • Cables are rated in categories or CAT ratings (or levels)

CAT Ratings CAT Rating Bandwidth Typical Throughput in Networks CAT 1 <1 MHz Analog

CAT Ratings CAT Rating Bandwidth Typical Throughput in Networks CAT 1 <1 MHz Analog phone lines – not data CAT 2 4 MHz Speeds up to 4 Mbps CAT 3 16 MHz Speeds up to 16 Mbps CAT 4 20 MHz Speeds up to 20 Mbps CAT 5 100 MHz Speeds up to 100 Mbps CAT 5 e 100 MHz Speeds up to 1000 Mbps CAT 6 200 -250 MHz Speeds up to 10000 Mbps

CAT Usage • Most new installations use CAT 5 e cable since it is

CAT Usage • Most new installations use CAT 5 e cable since it is cheaper than CAT 6 cable CAT level

Fiber Optic • Fiber optic cabling transmits light rather than electricity – Immune to

Fiber Optic • Fiber optic cabling transmits light rather than electricity – Immune to EMI – Very long distances – Consists of the fiber, cladding, and insulating jacket – Defined by fiber and cladding measurements – Most common is 62. 5/125 µm – Fiber generally requires two cables

Light Sources • Fiber optic cables use two possible light sources – Light Emitting

Light Sources • Fiber optic cables use two possible light sources – Light Emitting Diodes (LEDs) – called multimode – Lasers – called single-mode • Supports faster speeds and longer lengths

Networking Industry Standards

Networking Industry Standards

IEEE • Institute of Electrical and Electronic Engineers (IEEE) defines industry-wide standards • Organized

IEEE • Institute of Electrical and Electronic Engineers (IEEE) defines industry-wide standards • Organized the 802 committee in February of 1980 to define networking standards – Split up into smaller subcommittees

IEEE Subcommittees IEEE 802 LAN/MAN Overview & Architecture IEEE 802. 2 Logical Link Control

IEEE Subcommittees IEEE 802 LAN/MAN Overview & Architecture IEEE 802. 2 Logical Link Control (LLC) IEEE 802. 3 CSMA/CD access method (Ethernet) IEEE 802. 3 ae 10 Gigabit Ethernet IEEE 802. 5 Token Ring access method and Physical layer specifications IEEE 802. 8 Fiber Optic IEEE 802. 11 Wireless LAN Medium Access Control (MAC) and Physical layer specifications There are more subcommittees than listed in this table.