13.5 Quality of Service (QOS)

Question 1

Describe Quality Of Service (QOS)

Answer 1

refers to a set of mechanisms that try to guarantee timely delivery of important or time-sensitive communications. QoS is particularly important when implementing Voice over IP (VoIP), video over IP, online gaming, or unified communications, in which delay or data loss make the overall experience unacceptable.

Question 2

What metrics does QOS use to determine communication quality

Answer 2

Bandwidth – The capacity of a connection between two or more devices.
Loss – The percentage of packets that are lost during transit.
Delay – The amount of time that passes from when a packet is sent to when it arrives at its destination.
Jitter – The variation in delay of sending multiple packets from the same device.

Question 3

Describe Classification system

Answer 3

QoS prioritizes traffic from different data streams by using one of two classification systems:
Class of Service (COS)
Differentiated Services Code Point (DSCP)

Question 4

Describe Queue Schedulers

Answer 4

are used for congestion management and define how a device will work through its queue. Queue schedulers are special algorithms that determine which outgoing packets should receive priority and how the remaining packets in the queue should be handled.