Introduction to computer network and internet pdf
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- Computer Network Tutorial
- An Introduction to Computer Networks - Second Edition
- A Short Introduction to Computer Networks
- Introduction To Computer Networks
Computer Network Tutorial
For example: A printer can be controlled from any word processor at any computer on the network. This is an introductory unit where, you will be learning about the basic concepts regarding Computer Networks.
Figure 1 shows people working in an networked environment. The Computers on a network may be linked through Cables, telephones lines, radio waves, satellites etc. In wireless systems, antennas and Introduction to Computer Networks towers are also part of the network. Common topologies include a bus, star, ring, and mesh.
One of the most popular protocols for LANs is the Ethernet. We have seen that a computer network should satisfy a broad range of purposes and should meet various requirements. One of the main goals of a computer network is to enable its users to share resources, to provide low cost facilities and easy addition of new processing services.
The computer network thus, creates a global environment for its users and computers. In this type of network, short messages sent by any machine are received by all the machines on the network. The packet contains an address field, which specifies for whom the packet is intended. All the machines, upon receiving a packet check for the address field, if the packet is intended for itself, it processes it and if not the packet is just ignored.
Using Broadcast networks, we can generally address a packet to all destinations machines by using a special code in the address field. Such packets are received and processed by all machines on the network. One possible way to achieve Multicasting is to reserve one bit to indicate multicasting and the remaining n-1 address bits contain group number.
Each machine can subscribe to any or all of the groups. Broadcast networks are easily configured for geographically localised networks. Broadcast networks may be Static or dynamic, depending on how the channel is allocated. In Static allocation, time is divided into discrete intervals and using round robin method, each machine is allowed to broadcast only when its time slot comes up.
This method is inefficient because the channel capacity is wasted when a machine has nothing to broadcast during its allocated slot. Dynamic allocation may be centralised or decentralised. In centralised allocation method, there is a single entity, for example, a bus arbitration unit which determine who goes next and this is achieved by using some internal algorithm. In Decentralised channel allocation method, there is no central entity, here, each machine decides for itself whether or not to transmit.
The different types of Broadcast networks are: 1 Packet Radio Networks. Packet Radio broadcasting differs from satellite network broadcasting in several ways. In particular stations have limited range introducing the need for radio repeaters, which in turn affects the routing, and acknowledges schemes. Also the propagation delay is much less than for satellite broadcasting. Most LANs are confined to a single building or group of buildings within a campus.
Most LANs connect workstations and personal computers. This means that many users can share data as well as expensive devices, such as laser printers, fax machines etc. Users can also use the LAN to communicate with each other, by sending e-mail or engaging in chat sessions. For example, devices can be arranged in a ring or in a straight line. Some networks communicate via radio waves hence, do not use any connecting media. LANs are capable of transmitting data at very fast rates, much faster than data can be transmitted over a telephone line; but the distances are limited, and there is also a limit on the number of computers that can be attached to a single LAN.
Now a days Mbps are available. In these networks, when a packet travels from source to destination it may have to first visit one or more intermediate machines. Routing algorithms play an important role in Point-to-point or Switched networks because often multiple routes of different lengths are available. An example of switched network is the international dial-up telephone system. Packet Switched Networks. In Switched network, the temporary connection is established from one point to another for either the duration of the session circuit switching or for the transmission of one or more packets of data packet switching.
Circuit switching was originally developed for the analog based telephone system in order to guarantee steady and consistent service for two people engaged in a phone conversation. Analog circuit switching has given way to digital circuit switching, and the digital counterpart still maintains the connection until broken one side hangs up.
Packet Switched Networks Packet switched Networks use a networking technology that breaks up a message into smaller packets for transmission and switches them to their required destination. Unlike circuit switching, which requires a constant point-to-point circuit to be established, each packet in a packet- switched network contains a destination address. Thus, all packets in a single message do not have to travel the same path.
They can be dynamically routed over the network as lines become available or unavailable. The destination computer reassembles the packets back into their proper sequence. Packet switching efficiently handles messages of different lengths and priorities. By accounting for packets sent, a public network can charge customers for only the data they transmit.
Packet switching has been widely used for data, but not for real-time voice and video. However, this is beginning to change. IP and ATM technologies are expected to enable packet switching to be used for everything. The first international standard for wide area packet switching networks was X. ATM uses a cell-switching technology that provides the bandwidth sharing efficiency of packet switching with the guaranteed bandwidth of circuit switching.
Public packet switching networks may provide value added services, such as protocol conversion and electronic mail. Computer Networks …………………………………………………………………………………… …………………………………………………………………………………… …………………………………………………………………………………… 4 Differentiate between Broadcast and point-to-point networks. How different nodes in a network are connected to each other and how they communicate with each other is determined by the network's topology.
Topologies are either physical or logical. The bus topology connects workstations using a single cable. Each workstation is connected to the next workstation in a point-to-point fashion. All workstations connect to the same cable.
Figure 2 shows computers connected using Bus Topology. The cabling cost of bus systems is the least of all the different topologies. Each end of the cable is terminated using a special terminator. The common implementation of this topology is Ethernet. Here, message transmitted by one workstation is heard by all the other workstations. In a Star topology, the central hub is the host computer, and at the end of each connection is a terminal as shown in Figure 3.
Nodes communicate across the network by passing data through the hub. A star network uses a significant amount of cable as each terminal is wired back to the central hub, even if two terminals are side by side but several hundred meters away from the host.
The central hub makes all routing decisions, and all other workstations can be simple. An advantage of the star topology is, that failure, in one of the terminals does not affect any other terminal; however, failure of the central hub affects all terminals. This type of topology is frequently used to connect terminals to a large time-sharing host computer.
Data is transmitted around the ring in one direction only; each station passing on the data to the next station till it reaches its destination. Information travels around the ring from one workstation to the next. Each packet of data sent on the ring is prefixed by the address of the station to which it is being sent.
When a packet of data arrives, the workstation checks to see if the packet address is the same as its own, if it is, it grabs the data in the packet. If the packet does not belong to it, it sends the packet to the next workstation in the ring.
Faulty workstations can be isolated from the ring. When the workstation is powered on, it connects itself to the ring. When power is off, it disconnects itself from the ring and allows the information to bypass the workstation. The common implementation of this topology is token ring. A break in the ring causes the entire network to fail. Individual workstations can be isolated from the ring. The pattern of connection resembles a tree in which all branches spring from one root. Figure 5 shows computers connected using Tree Topology.
Tree topology is a hybrid topology, it is similar to the star topology but the nodes are connected to the secondary hub, which in turn is connected to the central hub. In this topology groups of star-configured networks are connected to a linear bus backbone.
An Introduction to Computer Networks - Second Edition
Even though the title of the text is "An Introduction to Networking", the author seems to assume that the student or reader knows a lot about the subject matter and terminology. Topics and some definitions are presented, however the author does a Comprehensiveness rating: 3 see less. Topics and some definitions are presented, however the author does a deep dive into the topic area quickly. Out-of-date information was identified.
A common form of Internet is collections of LANs connected by WA are form when distinct networks are connected with each other through routers and hosts.
A Short Introduction to Computer Networks
Modern world scenario is ever changing. Data Communication and network have changed the way business and other daily affair works. Now, they highly rely on computer networks and internetwork. A set of devices often mentioned as nodes connected by media link is called a Network.
The network is two or more connected computer which can share resource like a printer, an internet connection, application, etc. It is a collection of computer systems and devices which are linked together using a wireless network or via communication devices and transmission media. The network provides connectivity between computers and devices within a restricted range where only one entity is controlled or authorized to manage the entire system.
In computer networks, networked computing devices exchange data with each other using a data link. The best-known computer network is the Internet. Network computer devices that originate, route and terminate the data are called network nodes. Two such devices can be said to be networked together when one device is able to exchange information with the other device, whether or not they have a direct connection to each other.
Our Computer Networking Tutorial is designed for beginners and professionals. Our Computer Network tutorial includes all topics of Computer Network such as introduction, features, types of computer network, architecture, hardware, software, internet, intranet, website, LAN, WAN, etc. A computer network is a set of devices connected through links.
Introduction To Computer Networks
Internet , a system architecture that has revolutionized communications and methods of commerce by allowing various computer networks around the world to interconnect. By , approximately 4. The Internet is a vast network that connects computers all over the world.
Thomas G. Robertazzi received the Ph. He has published extensively in the areas of parallel processor scheduling, ad hoc radio networks, telecommunications network planning, switching, queueing and Petri networks. Robertazzi has also authored, co-authored or edited six books in the areas of networking, performance evaluation, scheduling and network planning. For thirteen years Prof. Skip to main content Skip to table of contents.
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