B1 - Network Types (Network Topologies)

Question 1

Extended Star

Answer 1

👉 This uses the same framework as the star topology, however, it has extra repeaters to extend the maximum range.

Benefit -

• It has a greater range than a star network, which is the main goal of the topology.

Drawback -

• Given star network was already expensive, this makes this even worse due to the cost of additional hubs and connections.

Question 1

Star Network topology

Answer 1

👉 This consists of a central hub (a network hub, switch or router) with each node (a device with the network) connected to it. Every node has a dedicated connection to the hub.

Benefit -

• If one node goes down, the network will remain running (except for the central hub).
• Easy to setup and troubleshoot.

Drawback -

• It requires a lot of cabling, making it expensive to set up & maintain.
• If the root node goes down the whole network goes down.

Question 2

Hierarchical

Answer 2

👉 known as a tree topology, or even a star-bus topology as it is hybrid of these two individual topologies. The devices connect to a central hub (a star network), which will in turn connect to a central bus backbone.

Benefit -

• Highly expandable as you can additional stars to the bus backbone.

Drawback -

• If the bus backbone goes down then the whole network goes down with it.

Question 3

Wireless Mesh

Answer 3

👉 A mesh topology consists of nodes connected with many redundant interconnections with several nodes. A full mesh will involve every node have a connection to every other node. A wireless mesh involves wireless access points connected in a mesh network structure.

Benefit -

• Mesh structure means if a node fails, then another will take its place.
• Fault identification is relatively easy.

Drawback -

• Lots of redundant cabling required to connect access points which can be costly.
• More complicated installation & setup.

Question 4

Ad-Hoc

Answer 4

👉 An ad-hoc network refers to a LAN that is built as devices connect – this means they don’t connect to any kind of central access point (like a router), instead they work by communicating with each other.

Benefit -

• No access points needed which make it cheap.

Drawback -

• As the ad-hoc network grows performance can suffer badly.

Question 5

Logical topologies

Answer 5

👉 Logical topologies are how the data passes through the network between devices, rather than how the devices are physically connected. The logical topology is defined by the network protocols which are being used to direct the data across the network.

👉 For example, the IEEE 802.3 standard for wired Ethernet uses a logical bus topology. However, it also uses a physical star topology. The Ethernet standard replaced other wired LAN standards, such as IEEE 802.5 Token Ring, which had a logical ring topology and a physical star topology.

👉 The IEEE 802.11 standard for Wireless LANs, doesn’t technically have a physical topology as it uses no cables. However, the different wireless modes can be considered physical topologies. However, a WLAN in infrastructure mode has devices connected to a central access point. This is similar to a star network. The logical topology is again a bus topology though.

Question 6

Peer to Peer (Network Architecture)

Answer 6

👉 A peer-to-peer network does not involve the use of a central server, instead, each computer acts as a server for the files it stores.

Benefit -

• No need for an expensive server as workload is spread
• No single point of failure as no central server
• Easier to set up than other architectures

Drawback -

• Access from other devices may slow performance for the user
• Each device controls its own security, leaving it vulnerable to threats
• Particularly easy for malware to spread

Question 7

Client/Server (Network Architecture)

Answer 7

👉 A client/server network involves a central server from which other PCs (clients) connect to. The server stores and manages access to resources or services.

Benefit -

• Security managed by a central server which makes it easier to protect against threats.
• Central location makes it easier to share and backup files.

Drawback -
- Servers can be expensive which makes setup costly.

• If the server goes down, nobody will be able to connect to the network, therefore susceptible to DoS attacks.

Question 8

Thin Client (Network Architecture)

Answer 8

👉 A thin client refers to a device on a client/server network that relies heavily on other devices (like the server) on the network to perform its roles. The majority of (or even all) processing & storage will be performed by the server.

Benefit -

• No storage on clients makes introducing malware very difficult

Drawback -
- You will need an even more powerful server which will be more expensive