Network topology is the physical interconnections of the elements (links, nodes, etc.) of a computer network.[1][2] 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 other 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 flows 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.
2.Examples of Network Topology, their Definition and post example picture
Star topology
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Bus topology
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Tree topology
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3. What is OSI Layer?
(Open Systems Interconnection) is a standard description or "reference model" for how messages should be transmitted between any two points in a telecommunication network.
4. Examples of OSI Layer, their definition in order.
Layer 1: The physical layer...This layer conveys the bit stream through the network at the electrical and mechanical level. It provides the hardware means of sending and receiving data on a carrier.
Layer 2: The data-link layer...This layer provides synchronization for the physical level and does bit-stuffing for strings of 1's in excess of 5. It furnishes transmission protocol knowledge and management.
Layer 3: The network layer...This layer handles the routing of the data (sending it in the right direction to the right destination on outgoing transmissions and receiving incoming transmissions at the packet level). The network layer does routing and forwarding.
Layer 4: The transport layer...This layer manages the end-to-end control (for example, determining whether all packets have arrived) and error-checking. It ensures complete data transfer.
Layer 5: The session layer...This layer sets up, coordinates, and terminates conversations, exchanges, and dialogs between the applications at each end. It deals with session and connection coordination.
Layer 6: The presentation layer...This is a layer, usually part of an operating system, that converts incoming and outgoing data from one presentation format to another (for example, from a text stream into a popup window with the newly arrived text). Sometimes called the syntax layer.
Layer 7: The application layer...This is the layer at which communication partners are identified, quality of service is identified, user authentication and privacy are considered, and any constraints on data syntax are identified. (This layer is not the application itself, although some applications may perform application layer functions.)
5. What is 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.
6. Example of Networking, Post at least 5 examples with picture.
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)
Metropolitan area network
A metropolitan area network (MAN) is a network that connects two or more local area networks or campus area networks together but does not extend beyond the boundaries of the immediate town/city. Routers, switches and hubs are connected to create a metropolitan area network.
Campus area network
A campus area network (CAN) is a computer network made up of an interconnection of local area networks (LANs) within a limited geographical area. It can be considered one form of a metropolitan area network, specific to an academic setting.
In the case of a university campus-based campus area network, the network is likely to link a variety of campus buildings including; academic departments, the university library and student residence halls. A campus area network is larger than a local area network but smaller than a wide area network (WAN) (in some cases).\
Storage area network
A storage area network is an network architecture to attach remote computer storage devices (such as disk arrays, tape libraries, and optical jukeboxes) to servers in such a way that the devices appear as locally attached to the operating system. A SAN typically is its own network of storage devices that are generally not accessible through the regular network by regular devices. The cost and complexity of SANs has dropped in recent years, resulting in much wider adoption across both enterprise and small to medium sized business environments.
Home area network
A home area network (HAN) or home hetwork is a residential local area network. It 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.
7.Example of networking devices and their functions, post at least 10 w/ picture.
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.
Network repeaters regenerate incoming electrical, wireless or optical signals. With physical media like Ethernet or Wi-Fi(wireless media), data transmissions can only span a limited distance before the quality of the signal degrades. Repeaters attempt to preserve signal integrity and extend the distance over which data can safely travel.
| Cable/DSL |
Typically DSL and Cable Modems connect to the carrier on one side and a modem on the other. Essentially you must discover the type of system your school uses to decide how to hook-up from there. This is the only type of system going into the home and thus will be of interest to you for that reason. The cable and the DSL lines are probably going to be 10Megabit since that is faster than any of the providers of this service are at this time.
The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed.
| Firewalls |
Basic security to control the flow of data in and out of a network. For our purposes this is controlled by the server that brings all connectivity to computers outside of the classroom. If this were a home cable or DSL line then you would want to install a firewall (software) that would control what other people on the internet can see in your personal computer.
Hubs
A hub is a small, simple network device that allows multiple connected computers to communicate. A hub may contain multiple ports that can connect a group of computers in a peer-to-peer fashion, accepting and repeating signals from each node. A slightly more sophisticated hub may contain multiple ports for devices and one port that connects to a network’s backbone. On Ethernet networks, hubs typically serve as the central connection point for branches of a star or star-based hybrid topology.
Switches
A network switch is a small hardware device that joins multiple computers together within one local area network (LAN). Technically, network switches operate at layer two (Data Link Layer) of the OSI model.
Bridges
A bridge device filters data traffic at a network boundary.Bridges have a single input and a single output port.They differ from repeaters in that they can interpret the data they retransmit.
Gateways
A network gateway is an internetworking system, a system that joins two networks together. A network gateway can be implemented completely in software, completely in hardware, or as a combination of the two. Depending on their implementation, network gateways can operate at any level of the OSI model from application protocols to low-level signaling.
Routers
A router is a multiport connectivity device that can integrate LANs and WANs running at different transmission speeds and using a variety of protocols. Routers operate at the Network layer (Layer 3) of the OSI Model. Routers have been slower than switches or bridges because they pay attention to information in Layers 3 and higher, such as protocols and logical addresses. Consequently, unlike bridges and Layer 2 switches, routers are protocol-dependent.They must be designed or configured to recognize a certain protocol before they can forward data transmitted using that protocol.
8. Example of networking cables and their functions, post at least 10 w/ picture.
Audio multi-core cable
A multicore cable "snake" helps sound engineers to route a number of signals without having to have a tangled mess of individual cables
Used in the audio recording and sound reinforcement fields, an audio multicore cable (most commonly known as a snake cable or just a snake) is a compact cable, typically about the diameter of a coin, which contains from 4 to 56 individual shielded pair microphone cables all housed by one rugged, heavy-duty common outer jacket. Each end of the multicore cable terminates in a "tail", which contains either a patchbay for female XLR or 1/4" jacks or male plugs.
Plenum cable
is cable that is laid in the plenum spaces of buildings. The plenum (pronounced /ˈplɛnəm/) is the space that can facilitate air circulation for heating and air conditioning systems, by providing pathways for either heated/conditioned or return airflows. Space between the structural ceiling and the dropped ceiling or under a raised floor is typically considered plenum; however, some drop ceiling designs create a tight seal that does not allow for airflow and therefore may not be considered a plenum air-handling space.
Power lines
Although power wires are not designed for networking applications, new technologies like Power line communication allows these wires to also be used to interconnect home computers, peripherals or other networked consumer products. On December 2008, the ITU-T adopted Recommendation G.hn/G.9960 as the first worldwide standard for high-speed powerline communications[3]. G.hn also specifies communications over phonelines and coaxial wiring.
Ethernet crossover cable
is a type of Ethernet cable used to connect computing devices together directly where they would normally be connected via a network switch, hub or router, such as directly connecting two personal computers via their network adapters.
Patch cable-
A patch cable is an electrical or optical cable, used to connect one electronic or optical device to another for signal routing. Devices of different types (ie: a switch connected to a computer, or switch to router) are connected with patch cords. It is a very fast connection speed. Patch cords are usually produced in many different colors so as to be easily distinguishable[2], and are relatively short, perhaps no longer than two Ethernet crossover cable.
Shielded Twisted-Pair Cable
Shielded twisted-pair (STP) cable combines the techniques of shielding, cancellation, and wire twisting. Each pair of wires is wrapped in a metallic foil. The four pairs of wires then are wrapped in an overall metallic braid or foil, usually 150-ohm cable. As specified for use in Ethernet network installations, STP reduces electrical noise both within the cable (pair-to-pair coupling, or crosstalk) and from outside the cable (EMI and RFI). STP usually is installed with STP data connector, which is created especially for the STP cable. However, STP cabling also can use the same RJ connectors that UTP uses.
Unshielded Twisted Pair (UTP)
UTP cable is a medium that is composed of pairs of wires (see Figure 8-1). UTP cable is used in a variety of networks. Each of the eight individual copper wires in UTP cable \is covered by an insulating material. In addition, the wires in each pair are twisted around each other. UTP cable relies solely on the cancellation effect produced by the twisted wire pairs to limit signal degradation caused by electromagnetic interference (EMI) and radio frequency interference (RFI). To further reduce crosstalk between the pairs in UTP cable, the number of twists in the wire pairs varies. UTP cable must follow precise specifications governing how many twists or braids are permitted per meter (3.28 feet) of cable.
Fiber-optic
communication is a method of transmitting information from one place to
another by sending pulses of light through an optical fiber. The light forms an
electromagnetic carrier wave that is modulated to carry information. First developed
in the 1970s, fiber-optic communication systems have revolutionized the telecommunications
industry and have played a major role in the advent of the Information Age. Because of its
advantages over electrical transmission, optical fibers have largely replaced copper wire
communications in core networks in the developed world.
Coaxial cable
or coax, is an electrical cable with an inner conductor surrounded by a
tubular insulating layer typically of a flexible material with a high dielectric constant,
all of which are surrounded by a conductive layer called the shield (typically of fine
woven wire for flexibility, or of a thin metallic foil), and finally covered with a thin
insulating layer on the outside. The term coaxial comes from the inner conductor and the
outer shield sharing the same geometric axis.
Twisted pair cabling
is a type of wiring in which two conductors (the forward and
return conductors of a single circuit) are twisted together for the purposes of canceling
out electromagnetic interference (EMI) from external sources; for instance,
electromagnetic radiation from Unshielded Twisted Pair (UTP) cables, and crosstalk
between neighboring pairs.
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