internet is a network which is for public, world where intranet and extranet is a network for private use,internet is a network where anybody can access, from around the world, but in intranet and extranet we add some privacy so only allowed people can access.there is no need for example of internet, hope u know!!lets give an example of intranet and extranet.we sometimes login some websites which requires our details to login, such as bank to view our bank statement, isp, university, so here we r connecting to extranet, bank allow us to access their internal network. In intranet internal users are allowed to use, such staff of bank, isp or other company which allowed their internal staff to use their network and no outsiders allowed in this case.hope it is alright!
Tuesday, 29 June 2010
Network Tropology
Network topology is defined as the interconnection of the various elements (links,nodes, etc.) of a computer network.[1][2] Network Topologies can be physical or logical. Physical Topology means the physical design of a network including the devices, location and cable installation. Logical topology refers to the fact that how data actually transfers in a network as opposed to its physical design.
Topology can be considered as a virtual shape or structure of a network. This shape actually does not correspond to the actual physical design of the devices on the computer network. The computers on the home network can be arranged in a circle shape but it does not necessarily mean that it presents a ring topology.
Any particular network topology is determined only by the graphical mapping of the configuration of physical and/or logical connections between nodes. The study of network topology uses graph theory. Distances between nodes, physical interconnections, transmission rates, and/or signal types may differ in two networks and yet their topologies may be identical.
A Local Area Network (LAN) is one example of a network that exhibits both a physical topology and a logical topology. Any given node in the LAN has one or more links to one or more nodes in the network and the mapping of these links and nodes in a graph results in a geometrical shape that may be used to describe the physical topology of the network. Likewise, the mapping of the data flow between the nodes in the network determines the logical topology of the network. The physical and logical topologies may or may not be identical in any particular network.
Contents[hide]
1 Basic topology types
2 Classification of network topologies
2.1 Physical topologies
2.1.1 Classification of physical topologies
2.1.1.1 Point-to-point
2.1.1.2 Bus
2.1.1.3 Star
2.2 Notes
2.3 Extended star
2.4 Distributed Star
2.4.1 Ring
2.4.2 Mesh
2.4.3 Tree
2.5 Signal topology
2.6 Logical topology
2.6.1 Classification of logical topologies
3 Daisy chains
4 Centralization
5 Decentralization
6 Hybrids
7 See also
8 References
9 External links
Network Architecture
Network architecture is the design of a communications network. It is a framework for the specification of a network's physical componentsand their functional organization and configuration, its operational principles and procedures, as well as data formats used in its operation.
In computing, the network architecture is a characteristics of a computer network. The most prominent architecture today is evident in the framework of the Internet, which is based on the Internet Protocol Suite.
In telecommunication, the specification of a network architecture may also include a detailed description of products and services delivered via a communications network, as well as detailed rate and billing structures under which services are compensated.
In distinct usage in distributed computing, network architecture is also sometimes used as a synonym for the structure and classification of distributed application architecture, as the participating nodes in a distributed application are often referred to as a network. For example, the applications architecture of the public switched telephone network (PSTN) has been termed the Advanced Intelligent Network. There are any number of specific classifications but all lie on a continuum between the dumb network (e.g., Internet) and the intelligent computer network(e.g., the telephone network). Other networks contain various elements of these two classical types to make them suitable for various types of applications. Recently the context aware network, which is a synthesis of the two, has gained much interest with its ability to combine the best elements of both.
Computer Network
"Computer networks" redirects here. For the periodical, see Computer Networks (journal).
Operating systems
Common features
Process management
Interrupts
Memory management
Virtual file system
Device drivers
Networking
Security
Graphical user interfaces
v • d • e
A computer network, often simply referred to as a network, is a collection of computers and devices connected by communications channels that facilitates communications among users and allows users to share resources with other users. Networks may be classified according to a wide variety of characteristics. This article provides a general overview of types and categories and also presents the basic components of a network.
Contents[hide]
1 Introduction
1.1 Purpose
2 Network classification
2.1 Connection method
2.2 Wired technologies
2.3 Wireless technologies
2.4 Scale
2.5 Functional relationship (network architecture)
2.6 Network topology
3 Types of networks
3.1 Personal area network
3.2 Local area network
3.2.1 Home area network
3.3 Campus network
3.4 Wide area network
3.5 Global area network
3.6 Enterprise Private Network
3.7 Virtual private network
3.8 Internetwork
3.8.1 Internet
3.8.2 Intranets and extranets
3.8.3 Overlay Network
4 Basic hardware components
4.1 Network interface cards
4.2 Repeaters
4.3 Hubs
4.4 Bridges
4.5 Switches
4.6 Routers
5 See also
6 References
7 Further reading
[edit]Introduction
A computer network allows sharing of resources and information among devices connected to the network. The Advanced Research Projects Agency (ARPA) funded the design of the Advanced Research Projects Agency Network (ARPANET) for the United States Department of Defense. It was the first operational computer network in the world.[1] Development of the network began in 1969, based on designs developed during the 1960s. For a history, see ARPANET.
[edit]Purpose
Computer networks can be used for several purposes:
Facilitating communications. Using a network, people can communicate efficiently and easily via e-mail, instant messaging, chat rooms, telephony, video telephone calls, and video conferencing.
Sharing hardware. In a networked environment, each computer on a network can access and use hardware on the network. Suppose several personal computers on a network each require the use of a laser printer. If the personal computers and a laser printer are connected to a network, each user can then access the laser printer on the network, as they need it.
Sharing files, data, and information. In a network environment, any authorized user can access data and information stored on other computers on the network. The capability of providing access to data and information on shared storage devices is an important feature of many networks.
Sharing software. Users connected to a network can access application programs on the network.
[edit]Network classification
The following list presents categories used for classifying networks.
[edit]Connection method
Computer networks can be classified according to the hardware and software technology that is used to interconnect the individual devices in the network, such as optical fiber, Ethernet, Wireless LAN, HomePNA, Power line communication or G.hn.
Ethernet uses physical wiring to connect devices. Frequently deployed devices include hubs, switches, bridges and/or routers. Wireless LAN technology is designed to connect devices without wiring. These devices use radio waves or infrared signals as a transmission medium. ITU-TG.hn technology uses existing home wiring (coaxial cable, phone lines and power lines) to create a high-speed (up to 1 Gigabit/s) local area network.
[edit]Wired technologies
Twisted pair wire is the most widely used medium for telecommunication. Twisted-pair wires are ordinary telephone wires which consist of two insulated copper wires twisted into pairs and are used for both voice and data transmission. The use of two wires twisted together helps to reduce crosstalk and electromagnetic induction. The transmission speed ranges from 2 million bits per second to 100 million bits per second.
Coaxial cable is widely used for cable television systems, office buildings, and other worksites for local area networks. The cables consist of copper or aluminum wire wrapped with insulating layer typically of a flexible material with a high dielectric constant, all of which are surrounded by a conductive layer. The layers of insulation help minimize interference and distortion. Transmission speed range from 200 million to more than 500 million bits per second.
Optical fiber cable consists of one or more filaments of glass fiber wrapped in protective layers. It transmits light which can travel over extended distances without signal loss. Fiber-optic cables are not affected by electromagnetic radiation. Transmission speed may reach trillions of bits per second. The transmission speed of fiber optics is hundreds of times faster than for coaxial cables and thousands of times faster than for twisted-pair wire.
[edit]Wireless technologies
Terrestrial Microwave – Terrestrial microwaves use Earth-based transmitter and receiver. The equipment look similar to satellite dishes. Terrestrial microwaves use low-gigahertz range, which limits all communications to line-of-sight. Path between relay stations spaced approx. 30 miles apart. Microwave antennas are usually placed on top of buildings, towers, hills, and mountain peaks.
Communications Satellites – The satellites use microwave radio as their telecommunications medium which are not deflected by the Earth's atmosphere. The satellites are stationed in space, typically 22,000 miles (for geosynchronous satellites) above the equator. These Earth-orbiting systems are capable of receiving and relaying voice, data, and TV signals.
Cellular and PCS Systems – Use several radio communications technologies. The systems are divided to different geographic area. Each area has low-power transmitter or radio relay antenna device to relay calls from one area to the next area.
Wireless LANs – Wireless local area network use a high-frequency radio technology similar to digital cellular and a low-frequency radio technology. Wireless LANs use spread spectrum technology to enable communication between multiple devices in a limited area. An example of open-standards wireless radio-wave technology is IEEE 802.11b.
Bluetooth – A short range wireless technology. Operate at approx. 1Mbps with range from 10 to 100 meters. Bluetooth is an open wireless protocol for data exchange over short distances.
[edit]Scale
Networks are often classified as local area network (LAN), wide area network (WAN), metropolitan area network (MAN), personal area network (PAN), virtual private network (VPN), campus area network (CAN), storage area network (SAN), and others, depending on their scale, scope and purpose. (e.g., Controller Area Network (CAN)) Usage, trust level, and access right often differ between these types of networks. For example, LANs tend to be designed for internal use by an organization's internal systems and employees in individual physical locations (such as a building), while WANs may connect physically separate parts of an organization and may include connections to third parties.
[edit]Functional relationship (network architecture)
Computer networks may be classified according to the functional relationships which exist among the elements of the network, e.g., active networking, client–server and peer-to-peer (workgroup) architecture.
[edit]Network topology
Computer networks may be classified according to the network topology upon which the network is based, such as bus network, star network, ring network, mesh network, star-bus network, tree or hierarchical topology network. Network topology is the coordination by which devices in the network are arranged in their logical relations to one another, independent of physical arrangement. Even if networked computers are physically placed in a linear arrangement and are connected to a hub, the network has a star topology, rather than a bus topology. In this regard the visual and operational characteristics of a network are distinct. Networks may be classified based on the method of data used to convey the data, these include digital and analog networks.
[edit]Types of networks
Common types of computer networks may be identified by their scale.
[edit]Personal area network
A personal area network (PAN) is a computer network used for communication among computer and different information technological devices close to one person. Some examples of devices that are used in a PAN are personal computers, printers, fax machines, telephones, PDAs, scanners, and even video game consoles. A PAN may include wired and wireless connections between devices. The reach of a PAN typically extends to 10 meters.[2] A wired PAN is usually constructed with USB and Firewire connections while technologies such as Bluetooth and infrared communication typically form a wireless PAN
[edit]Local area network
A local area network (LAN) is a network that connects computers and devices in a limited geographical area such as home, school, computer laboratory, office building, or closely positioned group of buildings. Each computer or device on the network is a node. Current wired LANs are most likely to be based on Ethernet technology, although new standards like ITU-T G.hn also provide a way to create a wired LAN using existing home wires (coaxial cables, phone lines and power lines).[3]
Typical library network, in a branching tree topology and controlled access to resources
All interconnected devices must understand the network layer (layer 3), because they are handling multiple subnets (the different colors). Those inside the library, which have only 10/100 Mbit/s Ethernet connections to the user device and a Gigabit Ethernet connection to the central router, could be called "layer 3 switches" because they only have Ethernet interfaces and must understand IP. It would be more correct to call them access routers, where the router at the top is a distribution router that connects to the Internet and academic networks' customer access routers.
The defining characteristics of LANs, in contrast to WANs (Wide Area Networks), include their higher data transfer rates, smaller geographic range, and no need for leased telecommunication lines. Current Ethernet or other IEEE 802.3 LAN technologies operate at speeds up to 10 Gbit/s. This is the data transfer rate. IEEE has projects investigating the standardization of 40 and 100 Gbit/s.[4]
[edit]Home area network
A home area network is a residential LAN which is used for communication between digital devices typically deployed in the home, usually a small number of personal computers and accessories, such as printers and mobile computing devices. An important function is the sharing of Internet access, often a broadband service through a CATV or Digital Subscriber Line (DSL) provider.
[edit]Campus network
A campus network is a computer network made up of an interconnection of local area networks (LANs) within a limited geographical area. The networking equipments (switches, routers) and transmission media (optical fiber, copper plant, Cat5 cabling etc.) are almost entirely owned (by the campus tenant / owner: an enterprise, university, government etc.).
In the case of a university campus-based campus network, the network is likely to link a variety of campus buildings including; academic departments, the university library and student residence halls.
[edit]Wide area network
A wide area network (WAN) is a computer network that covers a large geographic area such as a city, country, or spans even intercontinental distances, using a communications channel that combines many types of media such as telephone lines, cables, and air waves. A WAN often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer.
[edit]Global area network
A global area network (GAN) is a network used for supporting mobile communications across an arbitrary number of wireless LANs, satellite coverage areas, etc. The key challenge in mobile communications is handing off the user communications from one local coverage area to the next. In IEEE Project 802, this involves a succession of terrestrial WIRELESS local area networks (WLAN).[5]
[edit]Enterprise Private Network
An Enterprise Private Network is a network build by an enterprise to interconnect the various company sites (production sites, head offices, remote offices, shops etc.) in order to share computer resources over the network.
Sample EPN made of Frame relay WAN connections and dialup remote access.
Beginning with the digitalisation of telecommunication networks started in the 70's in the USA (by AT&T) [6] and propelled by the growth in computer systems availability and demands private networks have been built for decades without the need to append the term private to them. The networks were operated overtelecommunication networks and as per voice communications a certain amount of security and secrecy was expected and assumed.
But with the Internet in the 90's came a new type of network built over this Public infrastructure, using encryption to protect the data traffic from eaves-dropping (VPN). So the enterprise networks are now commonly referred toEnterprise Private Network in order to clarify that these are private networks (in opposition to public networks).
[edit]Virtual private network
Sample VPN used to interconnect 3 office and Remote users
A virtual private network (VPN) is a computer network in which some of the links between nodes are carried by open connections or virtual circuits in some larger network (e.g., the Internet) instead of by physical wires. The data link layer protocols of the virtual network are said to be tunneled through the larger network when this is the case. One common application is secure communications through the public Internet, but a VPN need not have explicit security features, such as authentication or content encryption. VPNs, for example, can be used to separate the traffic of different user communities over an underlying network with strong security features.
A VPN may have best-effort performance, or may have a defined service level agreement (SLA) between the VPN customer and the VPN service provider. Generally, a VPN has a topology more complex than point-to-point.
[edit]Internetwork
An Internetwork is the connection of two or more private computer networks via a common switching (OSI Layer 2) or routing technology (OSI Layer 3) and owned by separate entities (public or private). The result is called an internetwork. The Internet is an aggregation of many internetworks, hence its name was shortened to Internet.
Any interconnection between public, private, commercial, industrial, or governmental networks may also be defined as an internetwork or (more often) an extranet.
[edit]Internet
The Internet is a global system of interconnected governmental, academic, corporate, public, and private computer networks. It is based on the networking technologies of the Internet Protocol Suite. It is the successor of the Advanced Research Projects Agency Network(ARPANET) developed by DARPA of the U.S. Department of Defense. The Internet is also the communications backbone underlying theWorld Wide Web (WWW). The 'Internet' is most commonly spelled with a capital 'I' as a proper noun, for historical reasons and to distinguish it from other generic internetworks.
Participants in the Internet use a diverse array of methods of several hundred documented, and often standardized, protocols compatible with the Internet Protocol Suite and an addressing system (IP Addresses) administered by the Internet Assigned Numbers Authority and address registries. Service providers and large enterprises exchange information about the reachability of their address spaces through the Border Gateway Protocol (BGP), forming a redundant worldwide mesh of transmission paths.
[edit]Intranets and extranets
Intranets and extranets are parts or extensions of a computer network, usually a local area network.
An intranet is a set of networks, using the Internet Protocol and IP-based tools such as web browsers and file transfer applications, that is under the control of a single administrative entity. That administrative entity closes the intranet to all but specific, authorized users. Most commonly, an intranet is the internal network of an organization. A large intranet will typically have at least one web server to provide users with organizational information.
An extranet is a network that is limited in scope to a single organization or entity and also has limited connections to the networks of one or more other usually, but not necessarily, trusted organizations or entities (e.g., a company's customers may be given access to some part of its intranet creating in this way an extranet, while at the same time the customers may not be considered 'trusted' from a security standpoint). Technically, an extranet may also be categorized as a CAN, MAN, WAN, or other type of network, although, by definition, an extranet cannot consist of a single LAN; it must have at least one connection with an external network.
[edit]Overlay Network
An overlay network is a computer network that is built on top of another network. Nodes in the overlay can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network.
A sample overlay network: IP over SONET over Optical
Nodes in the overlay can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. For example, many peer-to-peer networks are overlay networks because they run on top of the Internet. Internet was built as an overlay on the telephone network [7].
Overlay networks have been around since the invention of networking when computer systems were connected over telephone lines using modem, before any data network existed.
Nowadays the Internet is the basis for many overlaid networks that can be constructed to permit routing of messages to destinations not specified by anIP address. For example, distributed hash tables can be used to route messages to a node having a specific logical address, whose IP address is not known in advance.
Overlay networks have also been proposed as a way to improve Internetrouting, such as through quality of service guarantees to achieve higher-quality streaming media. Previous proposals such as IntServ,DiffServ, and IP Multicast have not seen wide acceptance largely because they require modification of all routers in the network. On the other hand, an overlay network can be incrementally deployed on end-hosts running the overlay protocol software, without cooperation from ISPs. The overlay has no control over how packets are routed in the underlying network between two overlay nodes, but it can control, for example, the sequence of overlay nodes a message traverses before reaching its destination.
For example, Akamai Technologies manages an overlay network that provides reliable, efficient content delivery (a kind of multicast). Academic research includes End System Multicast and Overcast for multicast; RON (Resilient Overlay Network) for resilient routing; and OverQoS for quality of service guarantees, among others.
[edit]Basic hardware components
All networks are made up of basic hardware building blocks to interconnect network nodes, such as Network Interface Cards (NICs), Bridges, Hubs, Switches, and Routers. In addition, some method of connecting these building blocks is required, usually in the form of galvanic cable (most commonly Category 5 cable). Less common are microwave links (as in IEEE 802.12) or optical cable ("optical fiber"). An Ethernet card may also be required.
[edit]Network interface cards
A network card, network adapter, or NIC (network interface card) is a piece of computer hardware designed to allow computers to communicate over a computer network. It provides physical access to a networking medium and often provides a low-level addressing system through the use of MAC addresses.
[edit]Repeaters
A repeater is an electronic device that receives a signal, cleans it of unnecessary noise, regenerates it, and retransmits it at a higher power level, or to the other side of an obstruction, so that the signal can cover longer distances without degradation. In most twisted pair Ethernet configurations, repeaters are required for cable that runs longer than 100 meters. Repeaters work on the Physical Layer of the OSI model.
[edit]Hubs
A network hub contains multiple ports. When a packet arrives at one port, it is copied unmodified to all ports of the hub for transmission. The destination address in the frame is not changed to a broadcast address.[8] It works on the Physical Layer of the OSI model.
[edit]Bridges
A network bridge connects multiple network segments at the data link layer (layer 2) of the OSI model. Bridges do send broadcasts to all ports except the one on which the broadcast was received. However, bridges do not promiscuously copy traffic to all ports, as hubs do, but learn which MAC addresses are reachable through specific ports. Once the bridge associates a port and an address, it will send traffic for that address to that port only.
Bridges learn the association of ports and addresses by examining the source address of frames that it sees on various ports. Once a frame arrives through a port, its source address is stored and the bridge assumes that MAC address is associated with that port. The first time that a previously unknown destination address is seen, the bridge will forward the frame to all ports other than the one on which the frame arrived.
Bridges come in three basic types:
Local bridges: Directly connect local area networks (LANs)
Remote bridges: Can be used to create a wide area network (WAN) link between LANs. Remote bridges, where the connecting link is slower than the end networks, largely have been replaced with routers.
Wireless bridges: Can be used to join LANs or connect remote stations to LANs.
[edit]Switches
A network switch is a device that forwards and filters OSI layer 2 datagrams (chunk of data communication) between ports (connected cables) based on the MAC addresses in the packets.[9] This is distinct from a hub in that it only forwards the frames to the ports involved in the communication rather than all ports connected. A switch breaks the collision domain but represents itself a broadcast domain. Switches make forwarding decisions of frames on the basis of MAC addresses. A switch normally has numerous ports, facilitating a star topology for devices, and cascading additional switches.[10] Some switches are capable of routing based on Layer 3 addressing or additional logical levels; these are called multi-layer switches. The term switch is used loosely in marketing to encompass devices including routers and bridges, as well as devices that may distribute traffic on load or by application content (e.g., a Web URL identifier).
[edit]Routers
A router is an internetworking device that forwards packets between networks by processing information found in the datagram or packet (Internet protocol information from Layer 3 of the OSI Model). In many situations, this information is processed in conjunction with the routing table (also known as forwarding table). Routers use routing tables to determine what interface to forward packets (this can include the "null" also known as the "black hole" interface because data can go into it, however, no further processing is done for said data).
Perbandingan antara topology star,bus ring
Topolgi bus
Tpologi jaringan bus meruapakan beberapa simpul/node dihubungkan dg jalur data (bus).topolgi ini menyediakan 1 saluran untuk komunikasisemua perangkat shgg setiap perangkat harus bergantian seluran tersebut.hanya ada 2perangkat yg saling berkomunikasi dalam 1 saat.tiap node dapat melakukan tugas-tugas dan operasi yg berbeda.Untuk mengifisiensi penggunaan jaringan digunukan metode CSMA/CD(Carrier Sense Multiplay Access/Collision Detected)yg mernguragi masa tenggang(saluran kosong)dg mendeteksi tabrakan informasi.
Keuntungan Topolgi Bus
1.Mengurangi kabel&jarak LAN tidak terbatas.
2.Biaya instalasi sgt murah.
3.Mudah untuk menambah atau mengurangkan kompuer &nod
Kekurangan Topologi Bus
1.Memerlukan terminator untuk kedua ujng kabel tulang belakang
2.Perlu pengulang (repeater0jika LAN jauh.
3.Jika kabel tulabg belakang (backbone)/mana-mana nodnya bermasalah rangkaian tidak dapat berfungsi.
Topologi Ring
Mempunyai satu titik kesalahan,terletak pd hub.jika pusat hub mengalami kegagalan,maka seluruh jaringan akan gagal beroperasi.Memerlukan alat pd central poin untuk membroadcast ulang atau pergantian traffic jaringan (switch network rraffic).Penempatan kabel yg diguib\nakan ring menggunakan desain yg sederhanh,pada topologi ring,setiap computer yg pertama.
Keuntungan Topologi Ring
1.Setiap computer hak akses yg sama terhadap token,sehingga tidak akan ada computer yg memonopoli jaringan.
2.Data yg mengalir dalam satu arah sehingga terjadinya collision dapat dihindarkan.
Kekurangan Topolgi ring
1.Apabila ada satu computer dlm ring yg gagal berfungsi,maka akan mempengaruhi keseluruhan jaringan.
2.Sulit mengatsi kerusakan di jaringan yg menggunakan topolgo ring.
3Menambah atau menguirangikomputer akan mengacaukaun jaringan.
Topologi Star
Dalam topologi star,semua kabel di hubungkan dr computer-computer ke lokasi pusat(central location),dimana semuanya rehubung ke suatu alat yg dinamakan hub
Keuntungan Topologi star
Cukup mudah untuk mengubah dan menambah computer kedalam jaringan yg menggunakan topologi star tanpa mengganggu aktivitas jaringan yg sedang berkangsung.Pusat dari jaringan star merupakan tempat yg baik untuk menentukan diagnosa kesalahan yg terjadi dalam jaringan.Kita dapat memakai beberapa tipe kabel didalam jaringan yg sama dg hub yg dapat mengakomodasi tipe kabel yg berbeda
Kekurangan Topologi star
Memepunyai satu titik kesalahan,terletak pd hub.Jika hub pusat mengalami kegagalan,maka seluruh jaringan akan gagal beroperasi.memerlukan alat pd central poin untuk membroadcast ulang ppergantian traffic jaringan (switch network traffic).
Topologi Mesh
Topologi Mesh adalah suatu bentuk hubungan antar perangkat,dimana perangkat terhubung secara langsung ke perangkat lainya yg ada didalam jaringan.Akibatnya,dalam topologi ini setiap perangkat dapat berlomunikasi langsung dgn parangkat yg dituju(dedicated links)
Keuntungan Topologi Mesh
Memiliki sifat Robust,yaitu apabila terjadi gangguan pada koneksi computer A dgn computer B karena ruasaknya kabel koneksi(links).Memudahkan proses identifikasi permasakahan pd saat terjadi kerusakan koneksi pd computer.
Kekurangan Topologi Mesh
Membutuhkan banyak kabel dan Port I/o.Semakin banyk computer didalam topologi mesh mk di[erlukan semakin banyak kabel links dan port I/O.Hal tersebut sekaligus jg mengindisikasikan bahwa topologi jenis ini membutuhkan biaya yg relative mahal.Karena setiap computer harus terkoneksi secara langsung dgn computer kainya mk instalasi dan konfigurasi menjadi sulit.
Wednesday, 28 April 2010
Antivirus Install
If you don't know what your operating system is perform the following steps:
1. Click the Start button and select Run.
2. Type winver into the run box shown below then click the OK button.
3. If you get a window that looks like the one below then you have Windows XP. Click on the link to go to the instruction page.
4. If you get a window that looks like the one below then you have Windows 2000. Click on the link to go to the instruction page.
5. If you get a window that looks like the one below then you have Windows Vista. Click on the link to go to the instruction page.
How to install Office 2007
Step 1: Insert the Microsoft Office 2007 Enterprise CD. If the Setup Wizard does not automatically begin, then click Start > Run > D:\setup.exe
Step 2: Enter the Product Key from the back of the CD jacket. Note: This is a unique code. Please keep in a safe place!
Click Continue.
Step 3: Check the box "I accept the terms of this agreement" and click the Continue button.
Step 4: Choose an installation option, Upgrade (removes Office 2003) or Customize (keeps Office 2003 installed and adds Office 2007, allowing you to use them both).
Note: Outlook 2003 will be uninstalled in either option. Outlook will be updated and your user settings and mail will migrate to the new version.
If you click Upgrade, go on to Step 5.
If you click Customize, go on to Step 4a.
Step 4a: Click the radio button for "Keep all previous versions."
Click the Installation Options tab, left-click the first drop down box and click Run all from My Computer
Click Install Now.
Step 5: Installation will begin. It may take 15-30 minutes to finish.
Step 6: Click Close to complete the installation.
Step 7: The first time you launch any Office program, you will be prompted to activate the software. As long as you have an active Internet connection, choose the default option and click Next.
Step 8: When the activation finishes, click Close.
Step 9: Click OK to finish.
