What is networking
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Networking connects computing devices together to share data. It allows devices to communicate through a mix of hardware like cables and wireless equipment, and software like communication protocols. Networks can be categorized based on their geographic reach - local area networks (LANs) span a small area like a home or office, while wide area networks (WANs) connect across cities, states or globally. The largest public WAN is the Internet. Networks also use common protocols like TCP/IP to define the language devices use to communicate. While wired networks were traditionally used, wireless networking has become more popular for new installations.
![· Access control and network management capabilities
· Bandwidth scales as network grows
Disadvantages of Bridge:
· Does not limit the scope of broadcast
· Does not scale to extremely large networks
· Extremely large networks cannot rely on bridges
· Buffering and processing introduces delays
ADVANTAGES AND DISADVANTAGES OF HUB
Advantage:
Hub is less expensive product.
it is used for connect the multiple devices.
Disadvantages:
It will broadcast to all the ports
It runs half duplex
If 10 Ports in a hub it will share bandwidth of 100 MbPs.
So each port share 10 Mbps
MODEM
A modem (modulator-demodulator) is a device that modulates an analog carrier signal to
encode digital information, and also demodulates such a carrier signal to decode the
transmitted information. The goal is to produce a signal that can be transmitted easily and
decoded to reproduce the original digital data. Modems can be used over any means of
transmitting analog signals, from light emitting diodes to radio. The most familiar example is
a voice band modem that turns the digital data of a personal computer into
modulatedelectrical signals in the voice frequency range of a telephone channel. These
signals can be transmitted over telephone lines and demodulated by another modem at the
receiver side to recover the digital data.
SUBNET
A subnetwork, or subnet, is a logically visible subdivision of an IP network.[1]
The practice of
dividing a network into two or more networks is calledsubnetting.
All computers that belong to a subnet are addressed with a common, identical, most-
significant bit-group in their IP address. This results in the logical division of an IP address
into two fields, a network or routing prefix and the rest field or host identifier. The rest field is
an identifier for a specific host or network interface.](https://image.slidesharecdn.com/whatisnetworking-130505051104-phpapp02/85/What-is-networking-6-320.jpg)
What is networking
- 1. What is networking? In the world of computers, networking is the practice of linking two or more computing devices together for the purpose of sharing data. Networks are built with a mix of computer hardware and computer software. Area Networks Networks can be categorized in several different ways. One approach defines the type of network according to the geographic area it spans.Local area networks (LANs), for example, typically reach across a single home, whereas wide area networks (WANs), reach across cities, states, or even across the world. The Internet is the world's largest public WAN. Network Protocols In networking, the communication language used by computer devices is called the protocol. Yet another way to classify computer networks is by the set of protocols they support. Networks often implement multiple protocols to support specific applications. Popular protocols include TCP/IP, the most common protocol found on the Internet and in home networks. Wired vs Wireless Networking Many of the same network protocols, like TCP/IP, work in both wired and wireless networks. Networks with Ethernet cables predominated in businesses, schools, and homes for several decades. Recently, however, wireless networking alternatives have emerged as the premier technology for building new computer networks. Data communication The distance over which data moves within a computer may vary from a few thousandths of an inch, as is the case within a single IC chip, to as much as several feet along the backplane of the main circuit board. Over such small distances, digital data may be transmitted as direct, two-level electrical signals over simple copper conductors. Except for the fastest computers, circuit designers are not very concerned about the shape of the conductor or the analog characteristics of signal transmission.
- 2. DIFFERENT NETWORK TOPOLOGIES LAN NETWORKING NETWORK TOPOLOGIES TOPOLOGY – defines the structure of the network. There are two parts to the topology definition: the physical topology which is the actual layout of the wire (media) and the logical topology which defines how the media is accessed by the hosts. It refers also to how computers are being connected with each other. The types of topologies: 1. BUS TOPOLOGY In the bus topology, the computers are connected through a common communication media. A special type of central wire is used as communication media. This central wire is called Bus. The computer are attached through the bus the ends of the bus are closed with the terminator .The terminators are used to absorb signals. Bus topology use coaxial cables sections are connected to the B. N. C connectors. B.N.C connectors are often use to connect the computer through the main cable. These connectors can connect through two section of cable with the bus extending in both directions. The end device on the bus have the terminals on one connectors of T 2.STAR TOPOLOGY The star topology uses a separate cable for each work station as shown in fig.The cable connects the work station to a central device typically a HUB. The configuration provides a more reliable network that is easily expended. With star there is no central point of failure in the cable .if there is a problem with the cable only the station connected to that cable is a effected .to add more work stations simply connect another HUB 3.RING TOPOLOGY In ring topology each computer is connected to the next computer and the last computer is connected to the first computer. Thus a ring of computers is formed as shown in figure below. 4.MESH TOPOLOGY A mesh network or mesh topology uses separate cable to connect each device to every other device on the network, providing a straight communication path
- 3. HOSTS – devices that connect directly to a network segment. These hosts include computers, both clients and servers, printers, scanners and many other devices. These devices provide the users with connection to the network, with which the users share, create and obtain information. Network Interface Card (NIC) – is a printed circuit board that fits into the expansion slot of a bus on a computer’s motherboard or peripheral device. It is considered to be found in Layer 2 devices because each individual NIC throughout the world carries a unique code, called the Media Access Control (MAC) address. You can build computer networks with many different media types. Each media has advantages and disadvantages. What is an advantage for one media (category 5 cost) might be a disadvantage for another (fiber optic cost). Some of the advantages and disadvantages are: Cost Ease of installation Cable length REPEATER - is an electronic device that receives a signal and retransmits it at a higher level and/or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances. It is used when the type of cable (CAT5 UTP) is long. CAT5 UTP has a maximum length of 100 meters (approximately 333 feet). The purpose of a repeater is regenerate and retimes network signals at the bit level to allow them to travel a longer distance on the media. HUB - is a device for connecting multiple twisted pair or fiber optic Ethernetdevices together and thus making them act as a single network segment. There are different classifications of hubs in networking: 1. The first classification is active or passive. Most modern hubs are active; they take energy from a power supply to regenerate network signals. Some hubs are passive devices because they merely split signal for multiple users, like using a “Y” cord on a CD player to use more than one set of headphones. 2. Another classification of hubs is intelligent or dumb. Intelligent hubs have console ports, which mean they can be programmed to manage traffic in the network. Dumb hubs simply take an incoming networking signal and repeat it to every port without the ability to do any management. BRIDGE – refers to a device which has just two parts. It filters the frames and how this is actually accomplished. SWITCH – is to concentrate connectivity, while making data transmission more efficient. A device that is able to combine the connectivity of a hub with the traffic regulation of a bridge on each port. ROUTER – the first device that you will work with that us at the OSI’s network layer, or other known as Layer 3. The purpose of a router is to examine incoming packets, choose the best path for them in a network and then switch them to the proper outgoing port
- 4. OSI model The Open Systems Interconnection (OSI) model is a product of the Open Systems Interconnection effort at the International Organization for Standardization. It is a prescription of characterising and standardising the functions of a communications systemin terms of abstraction layers. Similar communication functions are grouped into logical layers. A layer serves the layer above it and is served by the layer below it. OSI layers OSI Model Data unit Layer Function Host layers Data 7. Application Network process to application 6. Presentation Data representation, encryption and decryption, convert machine dependent data to machine independent data 5. Session Interhost communication, managing sessions between applications Segments 4. Transport End-to-end connections, reliability and flow control Media layers Packet/Datagram 3. Network Path determination and logical addressing Frame 2. Data link Physical addressing Bit 1. Physical Media, signal and binary transmission LAN - Local Area Network A LAN connects network devices over a relatively short distance. A networked office building, school, or home usually contains a single LAN, though sometimes one building will contain a few small LANs (perhaps one per room), and occasionally a LAN will span a group of nearby buildings. In TCP/IP networking, a LAN is often but not always implemented as a single IP subnet.
- 5. In addition to operating in a limited space, LANs are also typically owned, controlled, and managed by a single person or organization. They also tend to use certain connectivity technologies, primarily Ethernet and Token Ring. WAN - Wide Area Network As the term implies, a WAN spans a large physical distance. The Internet is the largest WAN, spanning the Earth. A WAN is a geographically-dispersed collection of LANs. A network device called a router connects LANs to a WAN. In IP networking, the router maintains both a LAN address and a WAN address. A WAN differs from a LAN in several important ways. Most WANs (like the Internet) are not owned by any one organization but rather exist under collective or distributed ownership and management. WANs tend to use technology like ATM, Frame Relay and X.25 for connectivity over the longer distances. Metropolitan Area Network a network spanning a physical area larger than a LAN but smaller than a WAN, such as a city. A MAN is typically owned an operated by a single entity such as a government body or large corporation. ADVANTAGES AND DISADVANTAGES OF ROUTERS Advantage of Router - a) Router limits the collision domain. b) Router can function on LAN & WAN> c) Router can connects different media & architectures. d) Router can dtermine best path/route for data to reach the destination. e) Router can filter the broadcasts. Disadvantage of Router - a) Router is more expensive than Hub, Bridge & Switch. b) Router only waork with routable protocol. c) Routing updates consume bandwidth. d) Increase latency due to greater degree of packet filtering. ADVANTAGES AND DISADVANTAGES OF BRIDGES Advantages of Bridge: · Simple bridges are inexpensive · Simple configuration modes · Isolate collision domains with micro-segmentation · It increase network length
- 6. · Access control and network management capabilities · Bandwidth scales as network grows Disadvantages of Bridge: · Does not limit the scope of broadcast · Does not scale to extremely large networks · Extremely large networks cannot rely on bridges · Buffering and processing introduces delays ADVANTAGES AND DISADVANTAGES OF HUB Advantage: Hub is less expensive product. it is used for connect the multiple devices. Disadvantages: It will broadcast to all the ports It runs half duplex If 10 Ports in a hub it will share bandwidth of 100 MbPs. So each port share 10 Mbps MODEM A modem (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used over any means of transmitting analog signals, from light emitting diodes to radio. The most familiar example is a voice band modem that turns the digital data of a personal computer into modulatedelectrical signals in the voice frequency range of a telephone channel. These signals can be transmitted over telephone lines and demodulated by another modem at the receiver side to recover the digital data. SUBNET A subnetwork, or subnet, is a logically visible subdivision of an IP network.[1] The practice of dividing a network into two or more networks is calledsubnetting. All computers that belong to a subnet are addressed with a common, identical, most- significant bit-group in their IP address. This results in the logical division of an IP address into two fields, a network or routing prefix and the rest field or host identifier. The rest field is an identifier for a specific host or network interface.
- 7. Cisco Packet Tracer Cisco Packet Tracer is a powerful network simulation program that allows students to experiment with network behavior and ask “what if” questions. As an integral part of the Networking Academy comprehensive learning experience, Packet Tracer provides simulation, visualization, authoring, assessment, and collaboration capabilities and facilitates the teaching and learning of complex technology concepts. Packet Tracer supplements physical equipment in the classroom by allowing students to create a network with an almost unlimited number of devices, encouraging practice, discovery, and troubleshooting. The simulation-based learning environment helps students develop 21st century skills such as decision making, creative and critical thinking, and problem solving. Packet Tracer complements the Networking Academy curricula, allowing instructors to easily teach and demonstrate complex technical concepts and networking systems design. Packet Tracer features The current version of Packet Tracer supports an array of simulatedApplication Layer protocols, as well as basic routing with RIP, OSPF, and EIGRP, to the extent required by the current CCNA curriculum. While Packet Tracer aims to provide a realistic simulation of functional networks, the application itself utilizes only a small number of features found within the actual hardware running a current Cisco IOS version. Thus, Packet Tracer is unsuitable for modeling production networks. With the introduction of version 5.3, several new features were added, including BGP. BGP is not part of the CCNA curriculum, but part of the CCNP curriculum. Packet Tracer Cisco Packet Tracer 5.0 in Windows 7 Operating system Microsoft Windows and Debian- Like Linux