Data Communication and Computer Network i. About the Tutorial. This tutorial gives very good understanding on Data Communication and Computer. Networks. DCN Tutorial in PDF - Learn Data Communication & Computer Network in simple You can download the PDF of this wonderful tutorial by paying a nominal. Data Communication & Computer Network Tutorial for Beginners - Learn Data Communication & Computer Network in simple and easy steps starting from basic to advanced concepts with examples including overview and PDF Version.
|Language:||English, Dutch, Arabic|
|Genre:||Politics & Laws|
|ePub File Size:||18.70 MB|
|PDF File Size:||17.40 MB|
|Distribution:||Free* [*Register to download]|
A computer network can be defined as a set of computers connected together for the purpose of sharing resources. The most common resource shared today is. A computer can be connected to another one via a serial port but if we need to connect many computers to produce a network, this serial connection will not. Computer Networks - Computer Networks - Computer Network Video Tutorial - Computer Network in simple and easy steps starting from basic.
Question of security and integrity of user programs and data. Problem of data communication. Simply Easy Learning Page 5 Distributed operating System Distributed systems use multiple central processors to serve multiple real time application and multiple users. Data processing jobs are distributed among the processors accordingly to which one can perform each job most efficiently.
The processors communicate with one another through various communication lines such as high-speed buses or telephone lines.
These are referred as loosely coupled systems or distributed systems. Processors in a distributed system may vary in size and function.
These processors are referred as sites, nodes, and computers and so on. The advantages of distributed systems are following.
With resource sharing facility user at one site may be able to use the resources available at another. Speedup the exchange of data with one another via electronic mail. If one site fails in a distributed system, the remaining sites can potentially continue operating.
Better service to the customers. Reduction of the load on the host computer. Reduction of delays in data processing. The primary purpose of the network operating system is to allow shared file and printer access among multiple computers in a network, typically a local area network LAN , a private network or to other networks.
The advantages of network operating systems are following. Centralized servers are highly stable. Security is server managed. Upgrades to new technologies and hardware can be easily integrated into the system. Remote access to servers is possible from different locations and types of systems. The disadvantages of network operating systems are following. High cost of downloading and running a server.
Dependency on a central location for most operations. Regular maintenance and updates are required. Real time processing is always on line whereas on line system need not be real time. The time taken by the system to respond to an input and display of required updated information is termed as response time.
So in this method response time is very less as compared to the online processing. Real-time systems are used when there are rigid time requirements on the operation of a processor or the flow of data and real-time systems can be used as a control device in a dedicated application.
Download SQL Tutorial (PDF Version) - Tutorials Point
Real-time operating system has well-defined, fixed time constraints otherwise system will fail. For example Scientific experiments, medical imaging systems, industrial control systems, weapon systems, robots, and home-appliance controllers, Air traffic control system etc.
There are two types of real-time operating systems. Using the IP address, the computer can locate the web page requested by the user. So it forwards those requests to external DNS servers for resolution. A DNS server which is configured as a forwarder will behave differently than the DNS server which is not configured as a forwarder. Following are the ways that the DNS server behaves when it is configured as a forwarder: When the DNS server receives the query, then it resolves the query by using a cache.
If the forwarder is not available, then it will try to resolve the query by using root hint. It is a peripheral card attached to the PC to connect to a network. It provides a wireless connection to a local area network.
NICs were mainly used in desktop computers. It is used to specify data transfer rate. In 10Base-T, 10 specify the data transfer rate, i.
The word Base specifies the baseband as opposed to broadband. T specifies the type of the cable which is a twisted pair. It is specialized software which is used to provide network connectivity to a computer to make communication possible with other computers and connected devices.
NOS is the software which allows the device to communicate, share files with other devices.
Hm... Are You a Human?
The first network operating system was Novel NetWare released in Networks can be divided on the basis of area of distribution. It is created for personal use. Generally, personal devices are connected to this network. For example computers, telephones, fax, printers, etc.
CAN Campus Area Network : It is a connection of devices within a campus area which links to other departments of the organization within the same campus. MAN Metropolitan Area Network : It is used to connect the devices which span to large cities like metropolitan cities over a wide geographical area.
POP is responsible for accessing the mail service on a client machine. POP3 works on two models such as Delete mode and Keep mode. It is a unique address means no two devices can have same MAC addresses. IP address is a unique 32 bit software address of a computer in a network system. There are three ranges of IP addresses that have been reserved for IP addresses. They are not valid for use on the internet.
If you want to access internet on these private IPs, you must have to use proxy server or NAT server. A public IP address is an address taken by the Internet Service Provider which facilitates you to communication on the internet. This feature is generally found in Microsoft operating system. ADS is a microsoft technology used to manage the computers and other devices. ADS allows the network administrators to manage the domains, users and objects within the network. ADS consists of three main tiers: Domain: Users that use the same database will be grouped into a single domain.
Tree: Multiple domains can be grouped into a single tree. Forest: Multiple trees can be grouped into a single forest. Anonymous FTP is used to grant users access to files in public servers.
DCN Tutorial in PDF
Users which are allowed access to data in these servers do not need to identify themselves, but instead log in as an anonymous guest. A protocol is a set of rules which is used to govern all the aspects of information communication. The main elements of a protocol are: Syntax: It specifies the structure or format of the data. It also specifies the order in which they are presented.
Semantics: It specifies the meaning of each section of bits. Timing: Timing specifies two characteristics: When data should be sent and how fast it can be sent. First is directly used by the users and the second supports application programs.
The Domain Name System is the second type supporting program that is used by other programs such as to find the IP address of an e-mail recipient. A link is connectivity between two devices which includes the cables and protocols used in order to make communication between devices.
These seven layers can be grouped into three categories: Network layer: Layer 1, Layer 2 and layer 3 are the network layers.
Transport layer: Layer 4 is a transport layer. Application layer.That is if n users are present, each user can get time quantum. It is a peripheral card attached to the PC to connect to a network.
If the forwarder is not available, then it will try to resolve the query by using root hint. Computers automatically detect USB card and can install the drivers required to support the USB network card automatically. It is used to specify data transfer rate. A node can be computer, printer, or any other device capable of sending or receiving the data. Session layer establishes and maintains the session between the two users.