Understand Generation of Computers

 

 

Generation of Computers

 

There is FIVE generation of Computers                                                          

1.                   Vacuum Tubes {1940-1956}                                                                     

2.                   Transistors {1956-1963}                                                                            

3.                   Integrated Circuits {1964-1971}                                                              

4.                   Present Microprocessors {1971}                                                             

5.                   Artificial Intelligence {Present and Beyond}                          

 

There are FOUR types of Device.                    

                                               

1. Input Device {Keyboard, Mouse, Scanner, Microphone}            
2. Output Device {Monitor , Printer}                                                   
3. Processing Device {System Unit , Microprocessor, Motherboard}
4. Storage Device
1. Primary Storage Device {Random Access Memory (RAM)}
2. Secondary Storage Device {Read Only Memory (ROM) Such as Hard Disk ,Compact Disk }

SOFTWARE

A computer uses to store, process and retrieve information so it is called software.

                There are two types of Software

1. Application Software:è Application software refers to the software that enables a user to perform specific tasks.

For Example: - MS-Word is used to Create and edit documents.

 

2. System Software: è System Software refers to the software that enables a computer to perform functions.

For Example: - Windows OS is system software.

 

 

 

Networking: è A network is an interconnection of a group of computers that can communicate and share resources, Such as Hard Disks and Printers.

                Some of the advantages of Networks are:-

  Sharing of information over the network.

  Optimum utilization of hardware resources.

  Centralization of Data management.

 

Needs for Networking

 

v  To share computer files: -> Network provides very effective method to share the files with different users.

 

v  To share computer Peripherals: -> some computer devices are very expensive, Such as printers, Hard Disk, Network enable us to share these costly devices.

 

v  To enables Different computers to communicate with each other: -> Network allows different computer users to communicate and exchange information among themselves.

 

v  Fast and cheaper medium of communication: -> Computer sends speedily message through networking moreover through computers it is a cheaper way to transfer data.

 

v  Elementary Terminology: -> Basic terms used in a network.

 

Before installing a network the layout Architecture and type of network need to be decided

 

  Network Category

  Network Models.

  Network Topology: -> it is a schematic layout or map of the arrangement of nodes over the network. This layout also determines of the manner in which information is exchanged within the network.

 

 

There are FIVE Different types of Topologies.

1)       BUS Topology è The Bus Topology connects all the nodes on the network to a

Main cable called Bus.

2)       Star Topology – In this topology, the communications are routed through the Central system known as the ‘server’ as shown in figure. The network in this topology is vulnerable to fail if the server fails. Since, the communication is through the servers, the traffic on the network cable, is very high.

3)       Ring Topology – in this topology, the terminals are connected on the ring of cabling layout. The communication takes place from one terminal to the second,

4)       Mesh Topology

5)       Cellular Topology

 

 

Cross Wire Used for only connect PC to PC.

Simple and State wire used for connect Router to Computers.

                Wire Configuration {1.2.3.4.5.6.7.8}

        1 & 3 No. wire used for – Receiving Data

        2 & 6 No. wire used for – Sender wire

 

 

 

Evolution of Windows Clients/Server family

 

1990 èWindows 3.0 / _______

1993 èWin for workgroup 3.11 / Win NT advanced server 3.1

1994 è____ / Win NT server 3.5

1995 èWin 95 / Win NT server 3.51

1996 èWin NT Server 4.0 / Win NT Workstation 4.0

1998 èWin 98 / _________

2000 èWin Me / Win 2000 Server family

2001 èWin XP  /________

2003 è_______ / Win Server 2003

2007 èWin Vista /

2008 è Windows 7 / Windows server 2008 R2

2012 à Windows 8 / windows server 2012

 

 

 

Assignment of Port Numbers

Port Number Can Range between “0 to 65536”

 

1. Well-known port è The port ranging from “0 to 1023” are assigned & controlled by the Internet Authority.
2. Registered ports è The ports ranging from “1024 to 49,151” are not assigned. They can only be registered with Internet Authority to prevent duplication.
3. Dynamic ports è The ports ranging from “49,152 to 65,635” are neither controlled nor registered; they can be used by any process. It also called ephemeral Ports

 

Echo   è 7                                            Remote Desktop à 3389

LDAP – 389/636

FTP    è 21                                           TFTP è 69

Telnet è 23        

SMTP è 25                                          POP3 à 110

HTTP  è 80                                          HTTPS à 443

DNS    è 53                                          DHCP è 67/68

TCP     è 445                       UDP è

 

NNTP   è 119                      IMAP3 à 220

SNMP   è 161                     IMAP4 à 143

BGP      è  179                                                                    

RPC      è 111     

               

 

 

Data Packets: -> A Data Packets is the smallest unit of data that can travel over the network. It also contains the identification of the source and destination computer.

 

File System: -> A file system is maintained by an OS to keep track of the location of files and directories on a hard disk.

 

IP address: -> the address allocated to each node on a network is known as the IP address.

 

Subnets: -> to manage large network without affecting overall network performance you can divide a network into smaller networks is called Subnets. The method of IP addressing used to setup a subnet is known as subneting.

 

 Firewall: -> a firewall is a security mechanism to protect the data or, Networks from the threats, which can be a PC or a part of an Organization network from the other network which it interacts.

 

Hub è A Hub is a device that transmits information from one node to another.

 

Virtual memory è it refers to the space allocated on the hard disk to counter the low physical memory situation.

 

Bandwidth è It is the range of frequencies that signal, such as Analog and Digital can occupy over a given transmission medium.

 

Virus è A virus is a destructive program that infects system by replicating itself and spreading across the network.

 

Cryptography è It refers to protecting information by using codes and Cipher text. It is a fundamental part of message security.

 

Routers è It is a hardware devices that provide connectivity between WAN and LAN networks with different topologies or network using different network standards.

 

Routing è It is the process of determining the correct path for data packets and transmitting them from one network to another is called routing.

                There are two types of Routing:-

 

1. Direct Routing è If the destination host is attached to the same physical network as the source host. IP datagram can be directly exchanged. This is called Direct Routing. It occurs when both the source and destination hosts are connected to the same physical network.

 

2. Indirect Routing è It occurs when the destination host is not connected to a network it directly attached to the source host. The only way to reach the destination is via one or more IP Router.

 

Private network è A group of individual computer or network that support only node to node communication is called private network.

 

IP Multitasking è The process of sending a message simultaneously to more than one destination on a network is called IP Multitasking.

There are three types of IP Multitasking

1.       Unicast è Is works on the strategy of one to-one

2.       Multicast è Is works on the strategy of one-to-many

3.       Broadcast è is works on the strategy of one-to-all

 

Automated System Recovery (ASR) è It is a backup tool that helps you to recover the system in case of serious failure when all other recovery attempts fail.

An ASR preparation wizard that helps you to create in two parts for backup of your system.

First of all A floppy disk that has your system setting & other media that contains a Backup of your local Disk partitions.

 

Question: - What is Peer-to-Peer process?

Ans: - On a peer to peer process, no specific distinction exits between a client and server. Each node on the network has full control over the network resources.

 

Question: - What is ARP mechanism?

Ans: - The protocol resolves the MAC address of a node given its logical address.

 

Question: - What is RARP?

Ans: - It determines the IP address of host from its MAC address. It is operate at the internet layer.

 

Question: - What is ICMP?

Ans: - This protocol generates control message related to any error in connection or flow control.

 

 

 

Functions of the OSI Seven Layers:-

 

1. Physical Layer è This layer is the lowest layer of the OSI model and deals with the “Mechanical, Electrical, functional and procedural means” required for transmission of data, according to the OSI definition.

 

2. Data-Link layer è

 

3. Network layer è This layer provides a unique address to each node on a network.

 

4. Transport Layer è The transport layer is also responsible for the unreliable or reliable delivery of segments with the help of connectionless or connection-oriented services. The Transport layer also provides error control services when a data packet is lost during transmission, the Transport layer retransmits it after a specific interval.

 

5. Session Layer è The session layer establishes manages and synchronizes the communication between two communication nodes. It also defined as a logical connection between the two nodes. This layer can also control the direction in which data flows.

 

6. Presentation Layer è

 

7. Application Layer è

 

 

Features of Windows Server 2003 Family

 

1)       Active Directory:è It provides network security and performance.

 

2)       Remote Desktop Administration:è In enables system administrators to manage resources on a network from any computer on that network.

 

3)       Network load Balancing è this features reduces the response time of clustered application by distributing the network traffic among the less occupied server.

 

4)       Group Policy Result è It is a management feature that enables a system admin to determine the actual result of deploying a group policy on a target user to computer.

 

5)       Internet information Services è IIS 6.0

 

6)       Volume Shadow Copy Restore è This feature enables a system administrator to view version of shared files and folders on a client’s machine recover deleted or modified files compare the version of a file.

 

7)       Win Media services è It is a multimedia services that enables the distribution of digital media content over the web.