Tutorial 0: 19th September 2019 Flashcards
Fairness
Why is the JFI not considering the TCP flavours different nodes use a problem?
Different TCP flavours have different maximum data rates, so two nodes with different TCP flavours (or protocols altogether) with different max data rates may both be at their maximum but the JFI would still consider it unfair.
When may a 90%/10% share of a network between two nodes be fair? Would the JFI consider it fair?
When they are both using different TCP flavours (or protocols altogether) and are at their (different) maximum data rates. It would not.
Does the JFI take into account the needed data rate for different nodes?
No. This is an issue with the JFI.
How may quality of experience feed into network fairness?
If a user needs data more rapidly than another for the same quality of experience, for example, NLP or web page loading vs downloading a static movie, it may be fair for the first user to have priority for bandwidth on the network.
What are the 4 types of video streaming? Give examples of each.
interactive, real-time: skype call
interactive, non-real-time: bandersnatch
non-interactive, real-time: news broadcast
non-interactive, non-real-time: youtube video
What is quality of service?
Quality of service (QoS) is the description or measurement of the overall performance of a service, such as a telephony or computer network or a cloud computing service, particularly the performance seen by the users of the network.
What is quality of experience?
Quality of Experience (QoE) is a measure of the overall level of customer satisfaction with a vendor owing to human-perceptible changes in the performance of the service. QoE is related to but differs from Quality of Service(QoS), which embodies the notion that hardware and software characteristics can be measured, improved and perhaps guaranteed.
How is congestion in a computer network analogous to car traffic?
Both have waves on congestions and connections/cars at different speeds. The movement of packets and cars synchronise over time in both to make the congestion waves.
What is QUIC?
Quick UDP Internet Connections = a general-purpose transport layer network protocol intended to replace TCP. It encapsulates connections between hosts in UDP.
