Topology in Network Design (2)

8/6/2019 Topology in Network Design (2)

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TELECOMMUNICATION AND NETWORKS TYPES

& TOPOLOGIES OF NETWORKS

Presented by:-


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TYPES OF NETWORK TOPOLOGIES'

Network topologies are categorized into the following basic types:-

bus

ring star

tree

meshMore complex networks can be built as hybrids of two or more of the

above basic topologies.


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BUS TOPOLOGY

Bus networks (not to be confused with the system bus of a computer) use a

common backbone to connect all devices. A single cable, the backbonefunctions as a shared communication medium that devices attach or tap intowith an interface connector. A device wanting to communicate with anotherdevice on the network sends a broadcast message onto the wire that allother devices see, but only the intended recipient actually accepts and

processes the message

Ethernet bus topologies are relatively easy to install and don't require muchcabling compared to the alternatives. 10Base-2 ("Thin Net") and 10Base-5

("Thick Net") both were popular Ethernet cabling options many years ago forbus topologies. However, bus networks work best with a limited number ofdevices. If more than a few dozen computers are added to a network bus,performance problems will likely result. In addition, if the backbone cablefails, the entire network effectively becomes unusable.


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DIAGRAM OF BUS NETWORK TOPOLOGY

This diagramillustrates the bus network topology. A bus

topology suchas 10Base-2 or 10Base-5 Ethernet uses a single

communication backbone for all devices.


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RING TOPOLOGY

In a ring network, every device has exactly two neighborsfor communication purposes. All messages travel through a

ring in the same direction (either "clockwise" or

"counterclockwise"). A failure in any cable or device breaksthe loop and can take down the entire network.

To implement a ring network, one typically uses FDDI,SONET, or Token Ring technology. Ring topologies are found

in some office buildings or school campuses.


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DIAGRAM OF RING NETWORK TOPOLOGY

This diagramillustrates the ringnetwork topology. A ringtopology such

as FDDI or SONET sends messages clockwise or counterclockwise

through the shared link.


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STAR TOPOLOGY

Many home networks use the star topology. A star network features

a central connection point called a "hub" that may be a hub, switch

or router. Devices typically connect to the hub with Unshielded

Twisted Pair (UTP) Ethernet.

Compared to the bus topology, a star network generally requires

more cable, but a failure in any star network cable will only takedown one computer's network access and not the entire LAN. (If the

hub fails, however, the entire network also fails.)


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DIAGRAM OF STAR NETWORK TOPOLOGY

This diagramillustrates the star network topology. A star topology typically

uses a network hub or switchand is common in home networks.


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TREE TOPOLOGY

Tree topologies integrate multiple star topologies together

onto a bus. In its simplest form, only hub devices connect

directly to the tree bus, and each hub functions as the "root" of

a tree of devices. This bus/star hybrid approach supports

future expandability of the network much better than a bus

(limited in the number of devices due to the broadcast traffic it

generates) or a star (limited by the number of hub connectionpoints) alone.


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DIAGRAM OF TREE NETWORK TOPOLOGY

This diagramillustrates the tree network topology. A tree topology

integrates the star and bus topologies in ahybrid approach to

improve network scalability.


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DIAGRAM OF MESH NETWORK TOPOLOGY

This diagramillustrates the mesh network topology. A mesh topology

provides redundant communication paths between some or all

devices (partial or fullmesh).


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LAN LOCAL AREA NETWORK

A LAN connects network devices over a relatively short distance. Anetworked office building, school, or home usually contains a singleLAN, though sometimes one building will contain a few small LANs(perhaps one per room), and occasionally a LAN will span a group ofnearby buildings. In TCP/IP networking, a LAN is often but notalways implemented as a single IP subnet.

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, primarilyEthernet and Token Ring.


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METROPOLITAN AREA NETWORK (MAN)

A metropolitan area network (MAN) is a network that interconnects users withcomputer resources in a geographic area or region larger than that covered byeven a large local area network (LAN) but smaller than the area covered by awide area network (WAN). The term is applied to the interconnection of networksin a city into a single larger network (which may then also offer efficientconnection to a wide area network). It is also used to mean the interconnectionof several local area networks by bridging them with backbone lines. The latterusage is also sometimes referred to as a campus network.

Examples of metropolitan area networks of various sizes can be found in themetropolitan areas of London, England; Lodz, Poland; and Geneva, Switzerland.Large universities also sometimes use the term to describe their networks. Arecent trend is the installation of wireless MANs.


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WAN WIDE AREA NETWORK

As the term implies, a WAN spans a large physical distance. Internetis the largest WAN, spanning the Earth.

A WAN is a geographically-dispersed collection of LANs. A networkdevice 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 ratherexist under collective or distributed ownership and management.WANs tend to use technology like ATM, Frame Relay and X.25 forconnectivity over the longer distances.


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LAN, WAN AND HOME NETWORKING

Residences typically employ one LAN and connect to the

Internet WAN via an Internet Service Provider (ISP) using a

broadband modem. The ISP provides a WAN IP address to the

modem, and all of the computers on the home network use LAN

(so-called private) IP addresses. All computers on the home

LAN can communicate directly with each other but must go

through a central gateway, typically a broadband router, toreach the ISP.


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OTHER TYPES OF AREA NETWORKS

Wireless Local Area Network - a LAN based on WiFi wireless networktechnology

Metropolitan Area Network - a network spanning a physical area larger than aLAN 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. Campus Area Network - a network spanning multiple LANs but smaller than a

MAN, such as on a university or local business campus.

Storage Area Network - connects servers to data storage devices through atechnology like Fibre Channel.

System Area Network - links high-performance computers with high-speedconnections in a cluster configuration. Also known as Cluster Area Network.


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THANK YOU

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Topology in Network Design (2)