PHYSICAL Ring TOPOlogy
Physical Ring Topology — each node connects to exactly two other nodes.
- Data packets circulate the ring in just one direction
- Each node receives data from one node and transmits to the other.
- If the cable is broken at any point then the entire network is disabled.
- Removing/ adding a node requires the network to be stopped.
- All nodes needs to be powered at all times if the network is to operate.
Examples of physical ring topology
- FDDI (Fibre Distributed Data interface) and SONET(Synchronous Optical Network) —usually configured as physics rings and always operates as logical rings.
- Both use optic fibre as the transmission media.
- Both protocols use two physical rings with data circulating in different directions on each ring.
- FDDI — can be used for LANs, however it is commonly used for longer distance high speed connections.
- Usually used for connecting an organisations buildings.
- Distances should not exceed 30km
- Both rings can be used for data transmission, which effectively doubles the speed of data transfer.
- SONET — used for greater distances
- Distances can excess 100km.
- For long distance applications ,the second ring is gained solely as a backup should should a fault occur in the primary ring.
- FDDI — can be used for LANs, however it is commonly used for longer distance high speed connections.
aDVANTAGES AND DISADVANTAGES OF PHYSICAL Ring TOPOlogy
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dISADVANTAGES
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