Guide on Quality of Service (QoS)

What is Quality of Service (QoS)?
Quality of Service (QoS) is a set of technologies and techniques used in networking to manage data traffic to reduce packet loss, delay, and jitter on the network. It prioritizes certain types of data over others, ensuring that critical or sensitive data such as VoIP, video conferencing, and online gaming, gets priority over less important traffic.

Why Quality of Service (QoS) is important?
QoS is crucial in the modern internet where different types of data, requiring distinct levels of quality and speed, are sent across the network. Without QoS, all data is treated equally which can lead to delays and packet loss for critical services when the network is congested.

How Quality of Service (QoS) works?
QoS works by distinguishing and separating data traffic on a network by classifying data packets based on specific needs. It allocates resources, ensures bandwidth, controls latency and jitter, and manages any data congestion. Typically, QoS uses techniques such as prioritization, traffic shaping, and traffic policing to control data traffic.

Exam Tips: Answering Questions on Quality of Service (QoS)
1. Understand QoS Principles: Be aware of the basic principles that underlie QoS such as traffic prioritization, traffic shaping, and traffic policing.
2. Know the Applications of QoS: Remember that primary applications for QoS are VoIP, video conferencing, and online gaming, as these services require high-performance data transmission.
3. Understand Differentiation: Make sure to understand the differentiation between different types of traffic on the networks and how broadcast, multicast and unicast are dealt.
4. Versed with QoS Techniques: Be proficient with the techniques used to ensure QoS like Classification and Marking, Congestion Management, Congestion Avoidance, Policing and Shaping, and Link Efficiency.