TYPES NETWORKS&NETWORK TOPOLOGIES
Network What is Networking?
Process of connecting two or more computers for sharing.
Includes at least two computers.
Uses communications links to connect end devices with each others.
The rules of transmission is called protocols.
The sending file can be broken into segments, wrapped with network information called packets.
Client computers : End devices that used to access the shared resources. E.g.: Windows 10, windows 7, windows XP.
Server computers : Computers that provide shared resourcesE.g.: Windows server 8 or 2003, Linux, NetWare.
Network Interface Card : An interface that enables the computer to communicate over network.
Communication link : A physical media, that is needed by every computer to transmit data.
Switches : To connect more than two end devices in a network.
Routers : Intermediate devices that communicates between two different networks.
Information sharingTo send and/or receive data across the network.We can communicate via message applicationsWe can store data in a centralized server for easy management.
Resources sharingComputer resources can be shared in the network such as hard disk, printer, scanner, modem.Network administrator needs to monitor only print server instead each workstations.
Applicaion sharingSome companies may have business application that needs to be update by several users.Sharing makes it possible.It allows several users to work together on a single application.
TYPES OF NETWORKSPAN Personal Area NetworkWPAN - wireless Personal Area NetworkHAN - Home Area NetworkLAN Local Area NetworkWLAN -Wireless Local Area NetworkCAN -Campus Area NetworkMAN -Metropolitan Area NetworkSAN -System Area NetworkSAN -Storage Area NetworkPOLAN - Passive Optical LANEPN -Enterprise Area NetworkVPN -Virtual Area NetworkWAN -Wide Area Network
Personal area networkPAN is a personal devices network equipped at a limited area. PAN has such mobile devices: cell phone, tablet, laptop. Can also be wirelessly connected to Internet called WPAN.Handles the interconnection of IT devices at the surrounding of a single user. Appliances: cordless mice and keyboards, cordless phone, Bluetooth.
Pros and Cons:Expedient, lucrative and handy.Bad connection to other networks at the same radio bands.Slow data transfer speed, but comparatively safe.Distance limits.
Local area networkDesigned to operate over a small physical area such as an office, factory or a group of buildings.
Connects people and machines within a site.
Form of local (limited distance), shared packet network for computer communications.
Topologies such as Bus, Ring, Star, Tree etc. are used for LANs.
Various LAN protocols are Ethernet, Token Ring: TCP/IP, NetBIOS and NetBeui, IPX/SPX, Fiber Distributed Data Interchange (FDDI) and Asynchronous Transfer Mode (ATM).
BenefitsData communications over relatively short distances such as within an office, office building or campus environment. LANs are also being utilized for imaging applications, as well. They are also being used for video and voice communications, although currently on a very limited basis.
ApplicationsCommunications between the workstation and host computers, other workstations, and servers. The servers may allow sharing of resources. Resources could be information, data files, email, voice mail, software, hardware (hard disk, printer, fax, etc.) and other networks.
Wireless local area networkProvides wireless network communication over short distances using radio or infrared signals instead of traditional network cabling.
A type of local area network (LAN).
Built using wireless network protocols, most commonly either Wi-Fi or Bluetooth.
Contains devices like mobile phones, laptop and tablet computers, Internet audio systems, game consoles, Internet-enabled home appliances.
WLAN connections work via radio transmitters and receivers built into client devices
Campus area network
A computer network that links the buildings and consists of two or more LANs within the limited geographical area.
It can be the college campus, enterprise campus, office buildings, military base, industrial complex.
CAN is one of the type of MAN, on the area smaller than MAN.
The Campus networks usually use the LAN technologies, Ethernet, Token Ring, Fiber Distributed Data Interface (FDDI), Fast Ethernet, Gigabit Ethernet, Asynchronous Transfer Mode (ATM).
Metropolitan area networkA large computer network on the large geographical area that include several buildings or even the entire city (metropolis).
Used to combine into a network group located in different buildings into a single network.
The diameter of such a network can range from 5 to 50 kilometers.
It is also often used to provide public available connection to other networks using a WAN connection.
Wired optical connections are usually established via Ethernet, wireless - through Wi-Fi, Bluetooth, GPRS and other protocols.
MAN often acts as a high-speed network to allow sharing regional resources (like a big LAN).
Wide area networkWAN is the acronym for, Wide Area Network and refers to a network used to connect different equipments from remote areas.
This technology connects sites that are in diverse locations.
The geographical limit of WAN is unlimited.
Dedicated transoceanic cabling or satellite uplinks may be used to connect this type of network.
WAN must be scalable to long distances and many computers.
WANs need not be symmetric or have regular connections, i.e. each switch may connect to one or more other switches and one or more computers.
Storage/System area networkThe term SAN in computer networking most commonly refers to storage area networking but can also refer to system area networking.
A type of local area network (LAN) designed to handle large data transfers and bulk storage of digital information.
A SAN typically supports data storage, retrieval and replication on business networks using high-end servers, multiple disk arrays and interconnect technology.
Storage networks work differently than mainstream client-server networks due to the special nature of their workloads.
A system area network is a cluster of high performance computers used for distributed processing applications.
SAN vs. NAS
SAN technology is similar but distinct from network attached storage (NAS) technology.
Both Storage Area Networks (SANs) and Network Attached Storage (NAS) provide networked storage solutions.
A NAS is a single storage device that operates on data files, while a SAN is a local network of multiple devices that operate on disk blocks.
A NAS includes a dedicated hardware device often called the head that connects to a local area network (usually via Ethernet and TCP/IP).
A SAN commonly utilizes Fiber Channel interconnects and connects a set of storage devices that are able to share low level data with each other.
Passive optical local area networkPassive Optical LANs can span 20 km (12.5 miles) or more.
Reduces the operational footprint (less complexity)
Allows RF video deployment on a converged fiber network (no need for hard-line coax or amplifiers)
Passive Optical LAN is a new application of a proven access network solution. It is a better way to structure a LAN, because:Passive Optical LAN DistancesIt simplifies network moves, adds, and changesIs not limited by the distance and bandwidth constraints of twisted pair networks.Is secure by design, based on optical fiber and built-in encryption.
Uses smaller, lighter, less expensive cables to reduce pathway and space requirementsVirtually eliminates the need to refresh cabling infrastructuresAs technology evolves, only the active endpoints need a refresh
Enterprise private network
This type of networks are built and owned by businesses that want to securely connect its various locations to share computer resources.
Virtual private networkA VPN is typically a paid service that keeps your web browsing secure and private over public WiFi hotspots.
By extending a private network across the Internet, a VPN lets its users send and receive data as if their devices were connected to the private network even if theyre not.
Through a virtual point-to-point connection, users can access a private network remotely.
Near-me area networkA Near-me area network (NAN) is a logical communication network.
NAN focuses on the communication between wireless devices in the close proximity.
The NAN devices can belong to the different proprietary network infrastructures.
These can be for example different mobile carriers.NAN is realized the mobile Internet, GPS on the location mobile devices.
Home area networkA Home Area Networks (HAN) is a type of local area network that is used in an individual home.
The home computers can be connected together by twisted pair or by a wireless network.
HAN facilitates the communication and interoperability among digital devices at the home, allows to easier access to the entertainments and increase the productivity, organize the home security.
TYPES OF NETWORK TOPOLOGIESNetwork topology is the arrangement of various network elements
Used in data transmission and formation of interconnections like nodes and links with each other.
This linking of various elements is known as network topology.
Network topology is of two types:Physical topology - Interconnections that are visible, physical design of that network.Logical topology Mind mapping of such intercommunication diagrams.
When a map is drawn out of the interconnections, a geometrical shape is formed. This is the physical topography of that network.
So basically network topology is the layout of various connected devices.
This layout may be in the form of a circle but that doesnt means that it is a ring topology.
The shape of the connection is based on the fact that how the data is being transmitted and how are the devices linked.
Network topology is the arrangement of the electrical devices and cable wired that ensures how the devices are arranged.
Basic arrangements and types of network topologies.
Point to pointBusStarRing or circularMeshTreeHybridDaisy chainFully connected
Point to pointThis is the simplest and the earliest type of topology that links two end points.
This has been used by the telephonic systems and is the oldest type of network topology.
Point to point topology is the oldest type of network arrangement
A simple example of such a topology is how main frames and mini computers are connected to terminals.
There can be one terminal or various terminals but that one terminal server will have a point to point topological access to each of its subscriber.
Bus A single cable is connected to the main computer and that is further branched out to reach out to the various other computers out there.
This makes the topology cost effective as well.
It is difficult to find out which computer is malfunctioning.
This will cause not just an interruption while clearing the data out but also the loss of that data.
Ethernet is the most widely used network that has a bus topology.
Star Star topology is the arrangement of the computers in such a way that all the terminals or work stations are connected to the main central hub.
The terminals are referred to as the clients and the main central hub is referred to as the switch.
It is the easiest way of arranging a network topology with one central main computer connected to several other functioning terminals.
The disadvantage is that if an error occurs in the central hub the whole network shuts down.
Ring or CircularRing network topology is that in which all the terminals are arranged in a circular fashion.
All the data that is transmitted across the terminals is transferred in a circular pattern so that all the terminals receive it.
The flow of the data depends on the speed of the transmission.
Every node has a critical ring and every node has a signal repeater so that the data transmission remains strong.
MeshMesh topology is the most complicated to build as compared to other topologies.
In this kind of topology all the devices are connected to each other.
The data transferred from one system is sent and received by all the other systems.
The data is transferred in a multiple access pathways.
The cost of cable wired needed to connect all the systems is huge.
It provides maximum reliability in the areas of data transit as well as fault tolerance.
A tree network topology is the one in which there is a main functioning root node that is then connected to other servers via point to point topology in the levels of hierarchy.
In other words this topology is connected as a branching network of terminals.
Each level of terminals has a specific amount of nodes that it can connect.
The topology works in hierarchy fashion.
A hybrid network topology is the kind of arranging work stations in such a way that it doesnt resembles any of the basic network topologies like the star, bus or ring, etc.
Rather it amalgamates the two types of topologies to create a new one.
For example, the star ring network or a star bus network.
The bus trunk acts as the mother cable or the backbone of such a topology.
Daisy chain A daisy chain network topology allows the workstation to be connected in such a way that the data which has to be sent is transmitted in a sequence.
It makes it easy for adding more connections and station in the topology.
All the signals are transmitted station to station one after the other in a sequence that causes them to end up in their desired destination.
A daisy chain topology can be arranged in two ways:
A linear topology: Allows the station to send and receive the data in a two way fashion.This was difficult to build as all the stations required two receivers and two transmitters.
Ring topologyIt is formed by all the computers connected by each other through their ends. This ensures that all the data is transmitted by the computers one after the other and if there is a pathway break then the data is transmitted in the reverse fashion ensuring that the signals are received at their desired destination.
A fully connected network, complete topology, or full mesh topology is a network topology in which there is a direct link between all pairs of nodes.
In a fully connected network with n nodes, there are n(n-1)/2 direct links.
Networks designed with this topology are usually very expensive to set up.
Provides a high degree of reliability due to the multiple paths for data are provided by the large number of redundant links between nodes.
This topology is mostly seen in military applications.