"Ravi Namboori, a Cisco evangelist and an IT entrepreneur, is based out of Bay Area, California. Ravi Namboori holds nine Cisco certifications, in addition to one each from Microsoft and Novell in networking. Ravi Namboori earned his MBA from The F.W. Olin Graduate School of Business at Babson College. Think of a topology as a network's virtual shape or structure. This shape does not necessarily correspond to the actual physical layout of the devices on the network. For example, the computers on a home LAN may be arranged in a circle in a family room, but it would be highly unlikely to find a ring topology there. Network topologies are categorized into the following basic types: bus ring star tree mesh More complex networks can be built as hybrids of two or more of the above basic topologies. 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 backbone functions as a shared communication medium that devices attach or tap into with an interface connector. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other 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 much cabling compared to the alternatives. 10Base-2 ("ThinNet") and 10Base-5 ("ThickNet") both were popular Ethernet cabling options many years ago for bus topologies. However, bus networks work best with a limited number of devices. If more than a few dozen computers are added to a network bus, performance problems will likely result. In addition, if the backbone cable fails, the entire network effectively becomes unusable.

1. Network Topologies
Presented by
Ravi namboori

2. Network Topology
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

3. Physical 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

4. 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

5. 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

6. 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.

7. Tree Topology
A tree topology connects multiple star networks to other star networks.

8. 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.

9. Logical Topologies
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

10. Work group 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.

11. 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