Chapter 2 - Cabling and Topology Flashcards
Cabling and Topology
What is a network topology?
Network topology refers to HOW computers are connected within a computer network.
There are two types of topologies
- Physical (Structure / layout in physical space)
- Logical (How the signals travel)
By default, we are referring to the Logical topology.
What is a bus topology? Fault tolerance capabilities?
A bus topology refers to a linear (single) piece of cable where computers all attach to.
To avoid reflections when the signal hits the end of the wire (either end), terminators are placed at the ends.
If any part of this single cable breaks, the topology fails, so it has no fault tolerance.
What is a ring topology? Fault tolerance capabilities?
A ring topology refers to a looped piece of wire, where computers all attach to.
Computers each take a turn, decided by which host has the “token” at any given time. They pass the token around the ring.
If any part of this single loop cable breaks, the topology fails, so it has no fault tolerance.
What is a star topology? What else can it be called? Fault tolerance capabilities?
A star topology refers to a central “box” (usually a L2 switch, used to be a hub i.e. dumb repeater) which is connected to every host on the network via a dedicated cable for each.
It is also known as a “hub-and-spoke” topology.
It has fault tolerance, as any cable destruction will only take down the single host attached to the cable/switch.
What is a hybrid topology? Why do we need them?
Well, despite the fault tolerance benefits of a Star topology, this type of network topology was expensive at first. But the simplified physical layout of the topology was still beneficial.
So manufactures began combining the logical topology of bus or ring with the physical topology of star, by designing bus or ring circuitry inside the central boxes.
This allowed for a physical layout of a star topology, with the signal implementation of a bus or ring topology.
What topologies are used for Wireless networks? What defines these types of topologies?
Wireless topologies implement “mesh” structures, whereby hosts connect to other hosts via wireless channels.
A PARTIALLY meshed topology describes a situation where not every host connects directly to every other host, however, there is always at least one path from a host to another host on the network.
–> This type of topology requires at least two hosts to have redundant paths i.e. connect to more than 1 other host.
A FULLY meshed topology describes every host being able to connect DIRECTLY to every other host on the network.
What is a network technology?
A network technology (could) refer to the actual implementation of a network topology, through a recognized standard.
i.e. Doesn’t just specify topology, also specifies cabling and other mechanisms needed to actually have a functioning network.
Looks like 100BASE-T etc.
What are the two groups of network cables?
Fibre Optic and Copper.
