Network Topology is an arrangement of various elements of a Computer Network. Topology means arrangement of devices. We are having two types of network topologies. They are:
- Physical topologies
- Logical topologies
Physical topologies means physical arrangement of devices i.e., connecting two more systems by using cables etc. Physical topologies are 5 types they are:
- Bus Topology
- Ring Topology
- Star Topology
- Tree Topology
- Mesh Topology
- Bus Topology : The bus topology, each node (computer, server, peripheral etc.) attaches directly to a common cable. This topology most often serves as the backbone for a network. In some instances, such as in classrooms or labs, a bus will connect small workgroups
- Ring Topology : A ring topology features a logically closed loop. Data packets travel in a single direction around the ring.one network device to the next. Each network device acts as a repeater, meaning it regenerates the signal
- Star Topology : In a star topology each node has a dedicated set of wires connecting it to a central network hub. Since all traffic passes through the hub, the hub becomes a central point for isolating network problems and gathering network statistics.
- Tree Topology : A tree topology connects multiple star networks to other star networks.
- Mesh Topology : A network setup where each computer and network device is interconnected with one another, allowing for most transmissions to be distributed, even if one of the connections go down. This topology is not commonly used for most computer networks as it is difficult and expensive to have redundant connection to every computer. However, this topology is commonly used for wireless networks.
Logical topologies means logical arrangement of devices. In logical topologies we are having two models, they are:
- Work group model (or) peer to peer model (or) stand-alone model.
- Domain model or client –server model
- work group model (or) stand-alone model : It is also called as peer to peer model. Peer means individual computer. If you install client operating system (or) server operating system defiantly that computer belongs to work group model. Work group model computers does not depend on any other computers. In work group model computers we are creating local user accounts. For local user accounts we are using “SAM” Database. SAM-security accounts manager.
- Domain model : It is also called as client –server model. In this we are using active directory domain services(ADDS). ADDS is a database stores information on user identity, computers, groups, services and resources. ADDS domain controller also host the service that authentication user and computer accounts when they log on to domain PURPOSE OF ADDS: It provides user log on and authentication services using Kerberos protocol. By this service we are centralized and decentralized the resources management. To centrally organized and managed user accounts, computers, groups, passwords, accounts, network resource etc. Enables authorized users to easily locate network resources.