Networking: Network topologies

Question 1

What is a network topology?

Answer 1

The physical and logical arrangement of nodes and connections in a network. They decide arrangement of networks and the relative location of traffic flows. Network geometry can be defined as physical and logical topology.

Question 2

Describe a physical network topology.

Answer 2

Refers to the actual connections (wire, cables) of how the network is arranged. Set-up, maintenance and provisioning tasks require insight into the physical network.

Question 3

Describe a logical network topology.

Answer 3

A higher level idea of how the network is set up, like which nodes connect and in which ways, and how data is transmitted through the network. They include any virtual and cloud resources.

Question 4

How are network topology diagrams depicted?

Answer 4

They show devices depicted as network nodes and their connections with lines. The types of topologies depend on how the network needs to be arranged.

Question 5

Name the seven types of network topology.

Answer 5

Bus topology
Ring topology
Star topology
Tree topology
Mesh topology (Partial mesh and Full mesh)
Hybrid topology

Question 6

What are the defining characteristics of a bus topology?

Answer 6

It is a LAN topology in which each node is connected to a main cable or link called a bus. All connected notions can communicate with each other. If one station goes down, the rest can still communicate.

Question 7

What are the advantages of a bus topology?

Answer 7

Works well with small networks
Easiest topology to connect computers or peripherals in a linear fashion
Requires less cable length than star topologies
Simple and reliable

Question 8

What are the disadvantages of a bus topology?

Answer 8

Difficult to identify network problems
Hard to troubleshoot individual device issues
Not good for large networks
Terminators required for both ends
Additional devices slow down the network
If main cable damaged, network fails/splits in two

Question 9

Describe a ring topology.

Answer 9

Device connections create a circular pattern where each device is connected to two others. Packets of data travel from one device to the next till they reach their destination.

Question 10

In a ring topology, what happens in a unidirectional ring network?

Answer 10

The packets of data can only travel in one way around the network.

Question 11

In a ring topology, what happens in a bidirectional ring network?

Answer 11

Packets of data can move in either direction through the network.

Question 12

What are the advantages of a ring topology?

Answer 12

Data flows in one direction, avoiding packet collisions
Data is transferred at high speeds
Network server isn’t needed to control connectivity
Additional workstations can be added without impaction performance of the network

Question 13

What are the disadvantages of ring topology?

Answer 13

All data being transferred must pass from device to device, slowing it down
Entire network impacted if one workstation goes down
Hardware needed to connect each workstation to the network is more expensive than ethernet cables and hubs/switches

Question 14

What are the basic features of a star topology?

Answer 14

Also known as a star network, each component in this topology is physically connected to a central node like a hub/switch, which acts like a server and the connecting nodes like clients. When the central node receives a data packet from one of its clients, it can pass it on to other nodes in the network.

Question 15

What are the advantages of a star topology?

Answer 15

High reliability
High performing due to no data collisions
Less expensive because each device needs only one I/O port and needs to be connected with the hub with one link
Easy to install
Robust
Easy fault detection
No disruption when connecting/removing devices
Only one port required to attach to the hub

Question 16

What are the disadvantages of a star topology?

Answer 16

Requires more cable than a linear bus topology
If the connecting node fails, nodes attached to it are disabled
More expensive than bus topology due to value of connecting devices and extra hardware required
If hub goes down, so does the whole network
Hub requires more resources and regular maintenance because it is the central system of the star
Performance is predicated on the one concentrator i.e. hub

Question 17

Describe the tree topology.

Answer 17

Includes at least three specific levels in a topology hierarchy, where each node in a hierarchy level has a point-to-point connection with each adjacent node on its level. Ex: All secondary nodes have point-to-point attachments to each tertiary node in their jurisdiction, and the primary node has a point-to-point connection to each secondary node.

Question 18

What are the advantages of a tree topology?

Answer 18

Allows more devices to be attached to a single central hub thus decreasing the distance traveled by the signal to the devices
Allows the network to isolate and prioritize from different computers
Detection of error
Sturdiness
Easy expansion
Device support
Low cable requirement

Question 19

What are the disadvantages of a tree topology?

Answer 19

If central hub fails, whole system fails
High cost due to cabling
Weak security because all computers are interconnected
Maintenance is difficult and time-consuming due to large size and managing connections and identifying errors
Backbone is the main cable on which the entire network depends. If it defects, the whole network collapses. The point where failure occurs also decides the level of loss

Question 20

What is the formation of a mesh topology, and what are the differences between a full mesh and a partial mesh?

Answer 20

In a full mesh all nodes are connected with each other, so each node will have n-1 number of connections (n being the number of nodes present).

Partial meshes are more practical compared to the full mesh, where it is not necessary for all the nodes to be connected with every other one.

In it each node servers as a relay for other nodes, and routers provide the best, most efficient data path for effective communication.

Question 21

What are the advantages of a mesh topology?

Answer 21

Failure of a single device won’t affect the rest of the network
No traffic problems as there is a dedicated point-to-point link for every computer
Straightforward fault identification
Multiple paths to get to the destination plus tons of redundancy
High privacy and security
Consistent data transmission
Adding new devices doesn’t affect data transmissions
Robust features to beat any situation
No centralized authority

Question 22

What are the disadvantages of a mesh topology?

Answer 22

Costly compared to other topologies
Installation is extremely difficult
Power requirement is higher as all nodes need to remain active all the time to share the load
Complex process
Cost to implement is above other selections
High risk of redundant connections
Each node requires a further utility cost to think about
Maintenance is challenging

Question 23

Describe the hybrid topology?

Answer 23

Two or more topologies are combined to make a resultant topology which has the advantages (as well as weaknesses) of both topologies, which are consistent with the wants of the organization.

Ex: In a office, one department uses a ring topology, and another uses star topology, they result in a hybrid topology.

Question 24

What are the advantages of the hybrid topology?

Answer 24

Combines benefits of different topologies into one topology
Can be modified as per requirement
Extremely flexible
Very reliable
Easily scalable since hybrid topologies make integration of new hardware components easy
Easy error detecting and troubleshooting
Handles large volumes of traffic
Used to create large networks

Question 25

What are the disadvantages of a hybrid topology?

Answer 25

Expensive
Very complex design
Hardware has to be changed in order to connect topologies
Larger in scale so many cables required for installation
Hubs are very costly and need to be intelligent enough to work with different architectures
Installation is very difficult