W1 (Slides 01-03 - Forouzan Chapter 1) Flashcards
What is a simplex data flow, a key feature, and an example?
One way data flow.
Only 1 of the devices on a link can transmit
Keyboards are an example (can only introduce input)
What is a half-duplex data flow and an example?
Each station can transmit and receive, but not at the same time.
Radios are an example
What is full-duplex (duplex), key feature, and example?
Both stations can transmit and receive simultaneously.
Share the capacity of the link.
Telephone network.
What is a network?
The interconnection of a set of devices capable of communication.
What are the key attributes of a network?
Reliability, Performance, Security
What are the features of reliability
Accuracy of delivery
Frequency of failure
Link failure recoverability time
Robustness to disaster
Discuss performance
Often evaluated by the metrics: throughput and delay. (more throughput, less delay)
Measured largely through Transit time and Response time.
What is transit time?
Time taken for message to travel from one device to another
What is response time?
The elapsed time between an inquiry and response
What is security?
Protecting data from unauthorized access and damage
Implementing policies for recovering from breaches and data loss
What are the two types of connections? Briefly explain them.
Point-to-point (dedicated link between 2 devices)
Multipoint (more than 2 specific devices can share a link)
What are 4 topologies?
Fully-meshed
Star
Bus
Ring
What is fully-meshed topology, 2 advantages, a disadvantage, and an example
All devices are connected to each other via a dedicated P2P link.
ADVs: eliminates shared link traffic issues, is very robust.
DIS: lots of cables/connections makes installation and reconfiguration difficult.
EXAMPLE: regional telephone offices
What is a star topology, 2 advantages, a disadvantage, and an example.
Each device has a dedicated P2P link with a centralized controller (hub).
ADV: easy to install and reconfigure. robust,
DIS: big dependency on the hub, if that goes down whole network is down.
EX: LANs
What is a bus topology, a advantage, a disadvantage, example.
Where one cable forms the backbone that links all the devices on the network (multipoint connections).
ADV: Easy to install
DIS: not robust, fault breaks stop all transmission
EX: old ethernet LANs
What is a ring topology, 1 advs, 1 dis, an example.
All devices are connected to just the two devices either next to it (dedicated P2P).
ADV: easy to install and reconfigure
DIS: unidirectional traffic means that one break can disable whole net (solve via dual - ring topologies).
EX: old small LANs (schools, offices, etc)
