Enterprise Design Guide - Public - CommScope

Network Physical Topologies - Star vs. Ring
Physical topologies describe how the devices of the network are connected. There are two basics
ways:
Star Topologies
In a physical star topology, network devices are cabled to meet at a point of concentration,
usually a piece of active electronics called a hub, router, switch or node. These actives are
then connected to an intermediate point of concentration, and so on, until all traffic meets at a
central point.
Logical buses, rings and stars can be cabled together into a physical star. The hierarchical and
centralized nature of the star permits the easy concentration of cables and components, thus
easing maintenance burdens. Network additions can be accommodated in a straightforward
manner through a simply-achieved physical connection at any of the collection points.
TIA/EIA and other standards typically recommend a physical star architecture within buildings.
Ring Topologies
In a physical ring topology, the nodes of a network are all connected in a closed loop. Instead
of running back and forth between nodes, the signal travels in one direction around the ring.
In some networks, active and stand-by parallel circuits operate in both directions simultaneously
(counter-rotating ring). Rings are normally used in the campus backbone segment of a network.
Their advantage is that if a cable is cut or a node fails, the network will continue to operate.
However, adding more nodes to the ring is difficult. Trying to adapt bus or star logical
topologies to a ring may result in unacceptable connection loss.
Star physical topologies
are easier to work with.
Ring physical topologies are
more reliable due to their
inherent redundancy.
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