Transcript
Networking Devices Network Interface Card (NIC)
A card installed in a computer that enable the computer to communicate a network. It prepares data, sends data, and controls the flow of data. It can also receive and translate data into bytes for the CPU to understand.
Cable computers in a network are physically connected to each other using cables (transmission medium).
Hub/Switch Computers are connected by a cable to a device known as hub or switch. The hub/switch connect rest of the network. Each contain certain no of port. In the hub (a &b), the message is broadcast (copies) to all of the computers on the network.
a
b In the switch (c) Computers can talk with each other on private connections. Number of port typically 8,16,24 etc. C
Gateway Is used for interfacing with another network that uses different protocols to match the requirements of the destination system. Gateways can change the format of a message so that it will conform/translate the information.
Router highly intelligent device that connects multiple network types and determine the best path for sending data. Sometimes router is also called gateway. Bridge Connects different network segments that are the same type to each other and thus extend Physical networks.
Repeater is a network interconnection device that regenerate signals coming in one link onto another. So we can extend network physical distance
Modem modem is the combination of two word modulation & demodulation. Modem is a device which convert analog signal to digital signal & vice versa. Network Access point )NAP( act as an interface cable network & wireless device. We can also connect nodes(computer) to a access point.
Types of networks There are different types of computer networks: Local Area Network (LAN) Metropolitan Area Network (MAN)
Wide Area Network (WAN)
Local Area Network (LAN) is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building. Various configurations, called topologies, have been used to administer LANs
Metropolitan Area Network (MAN) are high speed networks that connects LAN’s to cover a city or a region of a city. It support interconnection between corporate data centers and internet service provider (ISP), and government, business etc.
A Wide Area Network (WAN) is a network that covers a broad area i.e. multiple cities, states, countries
Network topologies In computer networking topology refers to the layout or design of connected devices Physical Topology the physical design of the network including the devices, location & cable installation. Logical Topology
how data actually transfers in a network
Different Types of Topologies Bus Topology Ring Topology Star Topology
Mesh Topology Hybrid Topology
Bus Topology All the nodes (file server, workstations, and peripherals) on a bus topology are connected by one single cable. with a terminator at each end. Popular on LANs because they are inexpensive and easy to install.
BUS TOPOLOGY
DEFINITION
ADVANTAGE
DISADVANTAGE
All computers and devices connected to central cable
•Easy to connect a computer or peripheral to a linear bus.
•Entire network shuts down if there is a break in the main cable.
•Requires less cable length than a star topology.
•Terminators are required at both ends of the backbone cable. •Difficult to identify the problem if the entire network shuts down.
Ring Topology Cable forms closed ring or loop, with all computers and devices arranged along ring. Every device has exactly two neighbours for communication purposes. Data travels from device to device around entire ring, in one direction. Primarily is used for LANs, but also is used in WANs.
To implement a ring network we use the Token Ring technology.
A token, or small data packet, is continuously passed around the network. When a device needs to transmit, it reserves the token for the next trip around, then attaches its data packet to it, if not then it release it.
RING TOPOLOGY
DEFINITION
ADVANTAGE
DISADVANTAGE
Cable forms closed ring or loop, with all computers and devices arranged along ring.
•Data is transferred without a ‘bottle neck’.
•Data packets must pass through every computer between the sender and recipient therefore, this makes it slower.
•The transmission of data is relatively simple as packets travel in one direction only.
•If any of the nodes fail then the ring is broken and data cannot be transmitted successfully.
It is difficult to troubleshoot the ring.
Star Topology In a star network, each node (file server, workstations, and peripherals) is connected to a central device called a hub/switch. The hub/switch takes a signal that comes from any node and passes it along in the network.
STAR TOPOLOGY
DEFINITION •All devices connect to a central device, called hub/switch.
ADVANTAGE •Easy to install. •Easy to detect faults and to remove parts
DISADVANTAGE •Requires more length than a topology.
cable linear
If the hub/switch fails, nodes attached are disabled. More expensive than linear bus topologies because of the cost of the hubs/switches
Mesh Topology Each computer has a connection to every other devices. If one of the connection fail, data always has alternative path to get to its destination by taking the shortest route which means the least number of hops. On a large scale, you can connect multiple LANs using mesh topology with leased line.
MESH TOPOLOGY
DEFINITION
ADVANTAGE
In the mesh topology each computer are connected with each other by separate cable.
Provide redundant path between device. The network can be expanded without disruption to current user.
DISADVANTAGE Require more cable other topology .
than
Complicated implementation
Hybrid Topology It is a combination of two or more connected-network topologies (mentioned above).
Hybrid TOPOLOGY
DEFINITION
ADVANTAGE
Combination of any two or more network topologies
Handles large volume of traffic
Fault detection is easy. extremely flexible.
DISADVANTAGE Installation and configuration is difficult
More expensive than others
