Networking Basics

[InnerPeace]

Connecting to the Internet

Requirements for Internet connection

This page will describe the physical and logical requirements for an Internet connection.
The Internet is the largest data network on earth. The Internet consists of many large and small networks that are interconnected. Individual computers are the sources and destinations of information through the Internet. Connection to the Internet can be broken down into the physical connection, the logical connection, and applications.

A physical connection is made by connecting an adapter card, such as a modem or a NIC, from a PC to a network.

The physical connection is used to transfer signals between PCs within the local-area network (LAN) and to remote devices on the Internet.

The logical connection uses standards called protocols. A protocol is a formal de******ion of a set of rules and conventions that govern how devices on a network communicate. Connections to the Internet may use multiple protocols. The Transmission Control Protocol/Internet Protocol (TCP/IP) suite is the primary set of protocols used on the Internet. The TCP/IP suite works together to transmit and receive data, or information.

The last part of the connection are the applications, or software programs, that interpret and display data in an understandable form. Applications work with protocols to send and receive data across the Internet. A Web browser displays HTML as a Web page. Examples of Web browsers include Internet Explorer and Netscape. File Transfer Protocol (FTP) is used to download files and programs from the Internet. Web browsers also use proprietary plug-in applications to display special data types such as movies or flash animations.

[smile]

thank you innerpeace456
and we wann more

[InnerPeace]

PC basics

Computers are important building blocks in a network. Therefore, you must be able to identify the major components of a PC. Many networking devices are special purpose computers, with many of the same components as general purpose PCs.

A computer must work properly before it can be used to access information such as Web-based content. This will require troubleshoot basic hardware and software problems. Therefore, You must be familiar with the following small, discreet PC components:



You should also be familiar with the following PC subsystems:

Transistor – Device that amplifies a signal or opens and closes a circuit.
Integrated circuit – Device made of semiconductor material that contains many transistors and performs a specific task.
Resistor – An electrical component that limits or regulates the flow of electrical current in an electronic circuit.
Capacitor – Electronic component that stores energy in the form of an electrostatic field that consists of two conducting metal plates separated by an insulating material.
Connector – The part of a cable that plugs into a port or interface.
Light emitting diode (LED) – Semiconductor device that emits light when a current passes through it.
Printed circuit board (PCB) – A circuit board which has conducting tracks superimposed, or printed, on one or both sides. It may also contain internal signal layers and power and ground planes. Microprocessors, chips and integrated circuits and other electronic components are mounted on the PCB.
CD-ROM drive – A device that can read information from a CD-ROM.
Central processing unit (CPU) – The part of a computer that controls the operation of all the other parts. It gets instructions from memory and decodes them. It performs math and logic operations, and translates and executes instructions.
Floppy disk drive – A computer drive that reads and writes data to a 3.5-inch, circular piece of metal-coated plastic disk. A standard floppy disk can store approximately 1 MB of information.
Hard disk drive – A computer storage device that uses a set of rotating, magnetically coated disks called platters to store data or programs. Hard drives come in different storage capacity sizes.
Microprocessor– A microprocessor is a processor which consists of a purpose-designed silicon chip and is physically very small. The microprocessor utilizes Very Large-Scale Integration (VLSI) circuit technology to integrate computer memory, logic, and control on a single chip. A microprocessor contains a CPU.
Motherboard – The main printed circuit board in a computer. The motherboard contains the bus, the microprocessor, and integrated circuits used for controlling any built-in peripherals such as the keyboard, text and graphics display, serial ports and parallel ports, joystick, and mouse interfaces.
Bus– A collection of wires on the motherboard through which data and timing signals are transmitted from one part of a computer to another.
Random-access memory (RAM) – Also known as read-write memory because new data can be written to it and stored data can be read from it. RAM requires electrical power to maintain data storage. If a computer is turned off or loses power all data stored in RAM is lost.
Read-only memory (ROM) – Computer memory on which data has been prerecorded. Once data has been written onto a ROM chip, it cannot be removed and can only be read.
System unit – The main part of a PC, which includes the chassis, microprocessor, main memory, bus, and ports. The system unit does not include the keyboard, monitor, or any external devices connected to the computer.
Expansion slot – A socket on the motherboard where a circuit board can be inserted to add new capabilities to the computer. Figure shows Peripheral Component Interconnect (PCI) and Accelerated Graphics Port (AGP) expansion slots. PCI is a fast connection for boards such as NICs, internal modems, and video cards. The AGP port provides a high bandwidth connection between the graphics device and the system memory. AGP provides a fast connection for 3-D graphics on computer systems.
Power supply– The component that supplies power to a computer.



The following backplane components are also important:

Backplane – A backplane is an electronic circuit board containing circuitry and sockets into which additional electronic devices on other circuit boards or cards can be plugged; in a computer, generally synonymous with or part of the motherboard.
Network interface card (NIC) – An expansion board inserted into a computer so that the computer can be connected to a network.
Video card– A board that plugs into a PC to give it display capabilities.
Audio card – An expansion board that enables a computer to manipulate and output sounds.
Parallel port – An interface capable of transferring more than one bit simultaneously that is used to connect external devices such as printers.
Serial port – An interface that can be used for serial communication in which only one bit is transmitted at a time.
Mouse port – A port used to connect a mouse to a PC.
USB port– A Universal Serial Bus connector. A USB port connects devices such as a mouse or printer to the computer quickly and easily.
Firewire– A serial bus interface standard offering high-speed communications and isochronous real-time data services.
Power cord – A cord used to connect an electrical device to an electrical outlet that provides power to the device.
Think of the internal components of a PC as a network of devices that are all attached to the system bus.

[InnerPeace]

Network Interface Card

This page will explain what a NIC is and how it works. You will also learn how to select the best NIC for a PC.

A NIC, or LAN adapter, provides network communication capabilities to and from a PC. On desktop computer systems, it is a printed circuit board that resides in a slot on the motherboard and provides an interface connection to the network media. On laptop computer systems, it is commonly integrated into the laptop or available on a small, credit card-sized PCMCIA card. PCMCIA stands for Personal Computer Memory Card International Association. PCMCIA cards are also known as PC cards. The type of NIC must match the media and protocol used on the local network.

The NIC uses an interrupt request (IRQ), an input/output (I/O) address, and upper memory space to work with the operating system. An IRQ value is an assigned location where the computer can expect a particular device to interrupt it when the device sends the computer signals about its operation. For example, when a printer has finished printing, it sends an interrupt signal to the computer. The signal momentarily interrupts the computer so that it can decide what processing to do next. Since multiple signals to the computer on the same interrupt line might not be understood by the computer, a unique value must be specified for each device and its path to the computer. Prior to Plug-and Play (PnP) devices, users often had to set IRQ values manually, or be aware of them, when adding a new device to a computer.

These considerations are important in the selection of a NIC:

Protocols – Ethernet, Token Ring, or FDDI
Types of media – Twisted-pair, coaxial, wireless, or fiber-optic
Type of system bus – PCI or ISA

[InnerPeace]

NIC and modem istallation

This page will explain how an adapter card, which can be a modem or a NIC, provides Internet connectivity. You will also learn how to install a modem or a NIC.

A modem, or modulator-demodulator, is a device that provides the computer with connectivity to a telephone line. A modem converts data from a digital signal to an analog signal that is compatible with a standard phone line. The modem at the receiving end demodulates the signal, which converts it back to digital. Modems may be installed internally

or attached externally to the computer using a phone line.

A NIC must be installed for each device on a network. A NIC provides a network interface for each host. Different types of NICs are used for various device configurations. Notebook computers may have a built-in interface or use a PCMCIA card. Figure

shows PCMCIA wired, wireless network cards, and a Universal Serial Bus (USB) Ethernet adapter. Desktop systems may use an internal network adapter , called a NIC, or an external network adapter that connects to the network through a USB port.

Situations that require NIC installation include the following:

Installation of a NIC on a PC that does not already have one
Replacement of a malfunctioning or damaged NIC
Upgrade from a 10-Mbps NIC to a 10/100/1000-Mbps NIC
Change to a different type of NIC, such as wireless
Installation of a secondary, or backup, NIC for network security reasons
To perform the installation of a NIC or modem the following resources may be required:

Knowledge of how the adapter, jumpers, and plug-and-play software are configured
Availability of diagnostic tools
Ability to resolve hardware resource conflicts

[InnerPeace]

Overview of High-speed and dial-up connectivity

This page will explain how modem connectivity has evolved into high-speed services.

In the early 1960s, modems were introduced to connect dumb terminals to a central computer. Many companies used to rent computer time since it was too expensive to own an on-site system. The connection rate was very slow. It was 300 bits per second (bps), which is about 30 characters per second.

As PCs became more affordable in the 1970s, bulletin board systems (BBSs) appeared. These BBSs allowed users to connect and post or read messages on a discussion board. The 300-bps speed was acceptable since it was faster than the speed at which most people could read or type. In the early 1980s, use of bulletin boards increased exponentially and the 300 bps speed quickly became too slow for the transfer of large files and graphics. In the 1990s, modems could operate at 9600 bps. By 1998, they reached the current standard of 56,000 bps, or 56 kbps.

Soon the high-speed services used in the corporate environment such as Digital Subscriber Line (DSL) and cable modem access moved to the consumer market. These services no longer required expensive equipment or a second phone line. These are "always on" services that provide instant access and do not require a connection to be established for each session. This provides more reliability and flexibility and has simplified Internet connection sharing in small office and home networks.

[smile]

بجد يا innerpeace456
معلومات جامدة

[InnerPeace]

كويس يااسمايل ان الموضوع عجبك .. تابع بقى الباقى
___________________________

Wide-area networks (WANs)


This page will explain the functions of a WAN.

WANs interconnect LANs, which then provide access to computers or file servers in other locations. Because WANs connect user networks over a large geographical area, they make it possible for businesses to communicate across great distances. WANs allow computers, printers, and other devices on a LAN to be shared with distant locations. WANs provide instant communications across large geographic areas.

Collaboration software provides access to real-time information and resources and allows meetings to be held remotely. WANs have created a new class of workers called telecommuters. These people never have to leave their homes to go to work.

WANs are designed to do the following:

Operate over a large and geographically separated area
Allow users to have real-time communication capabilities with other users
Provide full-time remote resources connected to local services
Provide e-mail, Internet, file transfer, and e-commerce services

Some common WAN technologies include the following:

Modems
Integrated Services Digital Network (ISDN)
Digital subscriber line (DSL)
Frame Relay
T1, E1, T3, and E3
Synchronous Optical Network (SONET)

[InnerPeace]

Metropolitan-area networks (MANs)


This page will explain how MANs are used.

Wireless bridge technologies that send signals across public areas can also be used to create a MAN. A MAN usually consists of two or more LANs in a common geographic area. For example, a bank with multiple branches may utilize a MAN. Typically, a service provider is used to connect two or more LAN sites using private communication lines or optical services. A MAN can also be created using wireless bridge technology by beaming signals across public areas.

[InnerPeace]

Storage-area networks (SANs)


This page will discuss the features of SANs.

A storage-area network (SAN) is a dedicated, high-performance network used to move data between servers and storage resources. Because it is a separate, dedicated network, it avoids any traffic conflict between clients and servers.

SAN technology allows high-speed server-to-storage, storage-to-storage, or server-to-server connectivity. This method uses a separate network infrastructure that relieves any problems associated with existing network connectivity.

SANs offer the following features:

Performance – SANs allow concurrent access of disk or tape arrays by two or more servers at high speeds. This provides enhanced system performance.
Availability – SANs have built-in disaster tolerance. Data can be duplicated on a SAN up to 10 km (6.2 miles) away.
Scalability – A SAN can use a variety of technologies. This allows easy relocation of backup data, operations, file migration, and data replication between systems.

[InnerPeace]

Virtual private network (VPN)


This page will explain what a VPN is and how it is used.

A vitual private network (VPN) is a private network that is constructed within a public network infrastructure such as the global Internet. Using VPN, a telecommuter can remotely access the network of the company headquarters.

Through the Internet, a secure tunnel can be built between the PC of the telecommuter and a VPN router at the company headquarters.

[smile]

لا بقى دى كورس مكثف ولازم اثيته

[InnerPeace]

المشاركة الأصلية بواسطة smile

لا بقى دى كورس مكثف ولازم اثيته

فعلا يااسمايل هو كورس مكثف وهاتلاقى الديمو بتاعه هنا

[InnerPeace]

Overview

Copper cable is used in almost every LAN. Many different types of copper cable are available. Each type has advantages and disadvantages. Proper selection of cabling is key to efficient network operation. Since copper uses electrical currents to transmit information, it is important to understand some basics of electricity.

Optical fiber is the most frequently used medium for the longer, high bandwidth, point-to-point transmissions required on LAN backbones and on WANs. Optical media uses light to transmit data through thin glass or plastic fiber. Electrical signals cause a fiber-optic transmitter to generate the light signals sent down the fiber. The receiving host receives the light signals and converts them to electrical signals at the far end of the fiber. However, there is no electricity in the fiber-optic cable. In fact, the glass used in fiber-optic cable is a very good electrical insulator.

Physical connectivity allows users to share printers, servers, and software, which can increase productivity. Traditional networked systems require the workstations to remain stationary and permit moves only within the limits of the media and office area.

The introduction of wireless technology removes these restraints and brings true portability to computer networks. Currently, wireless technology does not provide the high-speed transfers, security, or uptime reliability of cabled networks. However, flexibility of wireless has justified the trade off.

Administrators often consider wireless when they install or upgrade a network. A simple wireless network could be working just a few minutes after the workstations are turned on. Connectivity to the Internet is provided through a wired connection, router, cable, or DSL modem and a wireless access point that acts as a hub for the wireless nodes. In a residential or small office environment these devices may be combined into a single unit.

Who complete this module should be able to perform the following tasks:

Discuss the electrical properties of matter
Define voltage, resistance, impedance, current, and circuits
Describe the specifications and performances of different types of cable
Describe coaxial cable and its advantages and disadvantages compared to other types of cable
Describe STP cable and its uses
Describe UTP cable and its uses
Discuss the characteristics of straight-through, crossover, and rollover cables and where each is used
Explain the basics of fiber-optic cable
Describe how fiber-optic cables can carry light signals over long distances
Describe multimode and single-mode fiber
Describe how fiber is installed
Describe the type of connectors and equipment used with fiber-optic cable
Explain how fiber is tested to ensure that it will function properly
Discuss safety issues related to fiber optics

[constantin]

اخى الحبيب innerpeace456 شكرا شكرا على موضوعك
انا عاوزا اقولك انى نقلت الموضوع على الجهاز بعد ما قراته سريعا تمهيدا لقرآته بتدقيق
و عاوز اقول ان المعلومات دى اهم من البرامج الجاهزه مائة مرة
فلا تبخل علينا بالمعلومات فى اى مواضيع اخرى و مرحبا بمشاركاتك القيمة فى المنتدى
وشكرا