# Group Members Adnan Usman Saad Subhan  Layout pattern of interconnections of links, nodes.  Network Topologies may be Physical or Logical.

## Presentation on theme: "Group Members Adnan Usman Saad Subhan  Layout pattern of interconnections of links, nodes.  Network Topologies may be Physical or Logical."— Presentation transcript:

 Layout pattern of interconnections of links, nodes.  Network Topologies may be Physical or Logical.

Basic Topology Types

 Seven Basic Topologies:-  Point-to-Point  Bus (point-to-multipoint) topology  Star topology  Ring topology  Tree topology  Mesh topology  Hybrid topology

 According to their physical span as follows:  LANs (Local Area Network)  WANs (Wide Area Internetworks)  Building or Campus Interworks

 Basic two categories:-  Physical Topology:- Layout of wiring, cables,, location of nodes & interconnections between the nodes and the cable. Layout of wiring, cables,, location of nodes & interconnections between the nodes and the cable.  Logical Topology:- Data passes through the network from one device to next without regard to the physical interconnection of the devices. Data passes through the network from one device to next without regard to the physical interconnection of the devices.

 Physical Topology is influenced by several factors:  Office Layout  Troubleshooting Techniques  Cost of Installation  Type of cable used

 Six types of Physical Topologies:-  Point-to-Point Topology  Bus Topology  Star Topology  Ring Topology  Mesh Topology  Tree Topology

 Point-to-Point (simplest topology):- Permanent link between two endpoints. Basic model of conventional telephony. Proportional to the number of potential pairs of subscribers. Expressed as Metcalfe’s Law.

 Point-to-Point (types) :-  Permanent (dedicated):- Permanently associated with the two endpoints. Permanently associated with the two endpoints. EXAMPLE: a television circuit from a parade route back to studio. EXAMPLE: a television circuit from a parade route back to studio.  Switched:- Circuit can be set up dynamically and dropped when no longer need. Circuit can be set up dynamically and dropped when no longer need. Basic mode of conventional telephony. Basic mode of conventional telephony.

 Bus Topology:- Each computer or server connected to the single bus through connector. Terminator is required to prevent signal from bouncing back. Finds the MAC address Finds IP address on the network. If address does not match, machine ignore data. If address does match, machine accept data.

 Bus Network Topology (types) :-  Linear Bus:- Network nodes are connected to common transmission medium. Network nodes are connected to common transmission medium. Commonly referred to as BACK-BONE. Commonly referred to as BACK-BONE.  Distributed Bus:- Network nodes are connected to common transmission medium. Network nodes are connected to common transmission medium. Created by adding branches to main section of transmission medium. Created by adding branches to main section of transmission medium.

 Star Network Topology:- (contrast bus topology) Each network host is connected to a central hub. Hub acts as a signal booster. Easiest topology to design and implement.  Advantage & Disadvantage:- Simplicity of adding additional nodes. Hubs represents a single point failure.

 Star Network Topology(types):-  Extended Star:- Based upon the physical star topology. One or more repeaters between the central nodes. Extended star topology are replaced with hubs or switches.  Distributed Star:- Individual networks. Based upon the physical star topology connected in linear fashion.

 Ring Network Topolog y:- Set up in circular fashion. Data travels around the ring in one direction. Each device on the right acts to keep signal strong. Each device incorporates a receiver for the incoming signal. Send the data on to the next device in the ring. Network is dependent. Signal or Data travels around the ring.

 Mesh Network Topology:- Proportional to the exponent of the subscribers number. Assuming that communicating groups of two endpoints. Including all the endpoints. Approximated by Reed’s Law.

 Mesh Network Topology (types):-  Fully Connected Mesh:- Generally too costly. Complex for practical networks. Topology is used when small number of nodes to be interconnected. Number of connections=n(n-1)/2

 Mesh Network Topology (types):-  Partially Connected Mesh:- Some of the nodes are connected to more than one other node in the network. This makes it possible to take advantage of some of the redundancy without expense & complexity.

 Tree Network Topology:- Central node connected to one or more other nodes. Each node in the network having a specific fixed number. Nodes connected it at the next lower level in the hierarchy. Individual peripheral nodes. Also known as a hierarchy network.

 Main Points: Contrast to the physical. Signals act on the network. Data passes through the network one device to the next. Data passes without regard to the physical interconnection. Data takes between nodes. Used as opposed to the actual connections between nodes.

 Main Points: Use combination of any two or more topologies. Resulting network does not exhibit one of the standard topologies.