- The term topology refers to the way a network is laid out.OR
- Cabling layout of a Network is called Network Topology.OR
- Physical layout of a network is called Network Topology.
- Network topologies are
- o Bus Topology or Linear Topology
- o Star Topology
- o Ring or Token Topology
- o Mesh Topology
- o Tree Topology
Bus Topology:
- All Computers will be attached with a long cable called a Bus or Trunk or Back bone cable.
- Multi-Point Communication.
- No security of data.
- Not recommended for large or sensitive networks.
- T-Connectors and Terminators are used.
- It uses Carrier Sense Multiple Access (CSMA) technology for data transmission.
Advantages are
- o Least amount of Cabling of any topology.
- o Suitable for small network
- o Adding additional nodes is easy
Disadvantages are
- o If main Cable breaks, then whole Network will goes down.
- o If any link goes down, then network will goes down.
- o Only one medium for Data Transmission so Transmission Speed is very slow.
- o Terminators are requires at the both ends.
Star Topology:
- Most common use now a day.
- Point-to-Point or Uni-cost Communication.
- Security of data.
- All Computers will be connected to a Central controller, usually called a HUB or Switch.
- Central device (Switch or HUB) has addresses of all computers connected to it.
- If one device wants to send the data to another, it sends the data to the controller, which then relays the data to other connected devices.
Advantages are
- o Fast Communication Speed as compared to Bus Topology.
- o Easy to install and wire.
- o If one computer fails, no effect on network.
- o Easy to detect and remove faults.
Disadvantages are
- o High installation cost as compared to Bus Topology.
- o If central device fails then entire network will goes down.
Ring Topology:
- Its shape is just like a ring.
- Also called Token Ring Topology.
- Connects the nodes (computers) in a circular Chain.
- Point-to-point Communication only with two devices on either side of it.
- A signal or Token is passed along the ring in the direction (Anti Clock Wise), from device to device, until it reaches its required destination.
- Better Performance than Bus Topology but less effective than Star Topology.
- Not very common used for large networks.
Advantages are
- Adding additional nodes is easy.
- All computers have equal access on network.
Disadvantages are
- Difficult to configure
- If Cable breaks, then whole Network will goes down.
- If any link goes down, then network will also goes down.
- Only one medium for Data Transmission so Transmission Speed is very slow.