What is Quality of Service (QoS) in Computer Networking ?
What is Quality of Service (QoS) in Networking ?
Quality of Service (QoS) is a set of network technologies that ensure a network’s ability to reliably run high-priority applications and traffic despite limited network resources. This is accomplished by QoS technologies, which provide differential handling and power allocation of complex flows in network traffic. This allows the network administrator to specify the order in which packets are processed as well as the amount of bandwidth available to that application or traffic flow.
Where is Quality of Service (QoS) mostly used?
QoS is often used in applications that are UDP-based. Essentially, QoS is used in networks that have users requiring heavy uses of video streams and VoIP devices. These tend to be UDP-based applications.
Understanding Quality of Service (QoS) and UDP/TCP protocols.
Any of the programs on your network are vulnerable to delays. These programs usually use the UDP protocol rather than the TCP protocol. When it comes to time sensitivity, the main difference between TCP and UDP is that TCP will retransmit missing packets while UDP will not. TCP should be used for file transfers between PCs because if any packets are misplaced, malformed, or arrive out of order, the TCP protocol will retransmit and reorder the packets to restore the file on the destination PC.
However, in UDP applications such as an IP phone call, any missing packet cannot be retransmitted because voice packets arrive in an ordered stream; re-transmitting packets is pointless. As a result, any missing or delayed packets for applications using the UDP protocol are a serious issue. In our voice call example, even a few packets lost would cause the voice to become choppy and unintelligible. Furthermore, the packets are susceptible to what is known as jitter. The variance in delay of a streaming program is referred to as jitter.
Network Quality of Service (QoS) primarily refers to the following:
- bandwidth (throughput)
- latency (delay)
- jitter (latency variation)
- error rate.
- Bandwidth is related to throughput.
- Latency relates to delays.
- Jitter relates to latency variation.
- Error rates relates to the degree in errors that packet drops.
As a result, QoS is especially important for high-bandwidth, real-time traffic like voice over IP (VoIP), video conferencing, and video-on-demand, which are highly sensitive to latency and jitter. Essentially, where you have bandwidth sensitive products and poor QoS management, you’ll see error rates or drops. For users, they will have poor experience in the application they are using.
These applications are often referred to as “inelastic,” since they have minimum bandwidth requirements and maximum latency limits.
Queuing and bandwidth control are QoS systems for ordering packets and allocating bandwidth. However, before they can be introduced, traffic must be classified using classification tools. Organizations will ensure the continuity and sufficient availability of resources for their most critical applications by categorizing traffic according to policy.
Should you keep QoS on or off?
Most consumers do not need to focus on QoS as application and network devices tend to handle QoS itself. Unless you are a network administrator or engineer and need to carve out traffic, especially for VoIP, then you may need it. Keep in mind that QoS often causes more issues than solves anything. It is best to monitor the traffic going in and out of your network prior to adjusting or implementing QoS solutions.