Network Topologies: Bus and Ring

Bus Topology

• It is easy to set up, handle, and implement
• This topology is suited for small networks
• It is very low in cost
• The cable length is limited, which consequently limits the number of network nodes
• This topology can only perform well for limited number of nodes
• The efficiency decreases as the number of devices connected to the bus increases
• This topology is suitable for networks with low traffic because high traffic increases the load and decreases network efficiency
• It is heavily dependent on the central bus, so a fault in the bus leads to network failure
• Isolating faults in network nodes is difficult
• Each device "sees" all data being transmitted, posing a security risk

Ring Topology

• The data transmitted between two nodes passes through all intermediate nodes
• No central server is required for management
• Traffic is unidirectional and data transmission is high-speed
• A ring is better at handling load than a bus
• Adding or removing network nodes is easy because it only requires changing two connections
• Its configuration makes it easy to identify faults in network nodes
• Each node has the opportunity to transmit data: it is a very organized network topology
• It is less costly than a star topology
• Failure of a single node can cause the entire network to fail
• Movement or changes to network nodes affect the entire network's performance
• Data must pass through intermediate nodes, making transmission slower than a star topology, transmission speed drops as nodes increases
• There is heavy dependency on the wire connecting the network nodes

Mesh Topology

• The arrangement of network nodes can transmit data from one node to many other nodes
• The failure of a single node does not cause the entire network to fail, as there are alternate paths for data transmission
• It can handle heavy traffic due to dedicated paths between any two network nodes
• Point-to-point contact between every pair of nodes makes fault identification easy
• Many connections serve no major purpose, leading to redundancy because every network node is connected to every other node
• A lot of cabling is required, leading to high setup and maintenance costs
• Administering a mesh network is difficult due to its complexity

Star Topology

• Due to its centralized nature, the topology offers simplicity of operation
• It achieves isolation of each device in the network
• Adding/removing network nodes is easy and it can be done without affecting the entire network
• Due to its centralized nature, detecting network device faults is easy
• Analyzing traffic is is easy, the topology poses a lesser security risk
• Data packets bypass passing through many nodes, unlike a ring network
• With a high-capacity hub present, traffic load can be handled at fairly decent speeds
• Network operation depends on the functioning of the central hub, leading to entire network’s failure if central hub fails
• The number of nodes depends on the capacity of the central hub
• The setup cost is quite high

Tree Topology

• A hierarchy of network nodes is implied, with the root node serving client nodes, which in turn serve other lower-level nodes
• The top-level node is mostly a mainframe, while other nodes are mini or microcomputers
• The node at each level could be forming a star network which combines star and bus topologies
• Tree topology is useful where star or bus cannot be implemented individually
• It is best suited for networking multiple departments of a university or corporation where each unit functions separately and is connected with the main node
• Centralization advantages achieved in a star topology are inherited by individual star segments in a tree network
• Each star segment has a dedicated link from the central bus, so failure of a segment does not affect the rest of the network
• Fault identification is easy
• The network is scalable through the addition of secondary nodes
• As multiple segments are connected to a central bus, the network depends heavily on the bus, impacting the entire network on failure
• Due to its size/complexity, maintenance is difficult and costly; also configuration is difficult compared to other topologies
• Scalability depends on the capacity of the central bus and on cable type

Hybrid Topology

• It combines two or more topologies to reap their advantages
• This topology’s advantages and disadvantages are a combination of the merits and demerits of the topologies used to structure it