QoS (Quality of Service) is an essential factor to consider when choosing a VoIP (Voice Over IP) provider. Some businesses tend to experience call quality issues even with a strong internet connection.

Solving those communication issues may cost a lot of time and money, especially if you have to temporarily disable your communications system. Setting up a solid VoIP QoS network can help you avoid these problems.

In this article you will learn what QoS is, how to set it up and the most essential best practices.

What exactly is Quality of Service (QoS)?

Quality of Service is defined by VoIP providers and IT professionals as the overall performance of a VoIP system or network. 

This performance is often tested by examining objective data like bandwidth use, call latency, error rates, etc. 

Subjective data, such as end-users’ perception about the system’s performance, is also considered.

QoS (Quality of Service) can also be considered as the process to prioritize connection traffic and ensure minimum bandwidth use.

Because several team members need to be connected at the same time, you’ll need to avoid one specific user to jeopardize the experience by consuming too much bandwidth. That’s what QoS Does.

Why is VoIP QoS Important For Your Business?

VoIP has quickly become the preferred communication technology for many small and medium-sized organizations. 

While numerous vendors provide various VoIP packages with their own set of features, you should check their QoS practices to determine which one would best suit your company’s demands. 

Here’s a brief rundown of what QoS is and some key questions to ask prospective suppliers.

As business conditions change, your company must adjust. It may be forced to restart the QoS deployment cycle by redefining their objectives, tweaking and testing designs, rolling out new designs, and monitoring them to determine whether they fit the redefined goals.

QoS policing is simply the management of data packets traveling through a network at a given time. 

QoS standards have been designed to enable network managers to prioritize certain apps based on their essential business requirements, giving greater weight to particular data delivery types over others.

QoS regulations are critical for organizations that rely on video conferencing, online training, and media streaming to carry out their daily operations. 

QoS protects the transmission of this sort of data from being compromised by excessive network traffic levels. Additionally, it addresses these concerns by identifying and implementing several functions, including the following:

Recommended VoIP QoS Setting

In any VoIP system, QoS is a crucial concern. The goal is to determine how to ensure that packet traffic for a voice or other media doesn’t get delayed or interrupted due to interference from lower priority traffic. 

Your business may quantify QoS by employing a variety of parameters, including the following:

  • Packet loss:  When network links get overcrowded, routers and switches begin losing packets. When packets are lost during real-time communication, such as voice or video conversations, jitter and pauses in speech occur. When a queue, or line of packets waiting to be transmitted overflows, you’ll need to fix packet loss.
  • Bandwidth: The ability of a communications network to send a volume of information from one location to another in a given time frame. QoS improves network performance by controlling bandwidth and allocating additional resources to high-priority applications with stringent performance needs.
  • Network Jitter: This is caused by network congestion, time drift, and route modifications. Jittering decreases the quality of voice and visual communication.
  • Latency:  This is a term used to describe the amount of time it takes for a packet to travel from its origin to its destination. Latency should be kept as low as feasible. Users may encounter an echo or a time delay if their VoIP call has a significant latency.
  • The average opinion score (MOS): This measure assesses voice quality by using a five-point scale, with five representing the highest quality.
  • Network Topologies: The topologies of LAN and WAN networks decide whether you can affect its endpoints. The network maintained by your router is referred to as a local area network (LAN). Wide Area Network (WAN) refers to the internet’s more extensive network. For example, VoIP works by sending packets from your phones to their destination via your LAN and the WAN.

How to Setup VoIP QoS

There are 3 different models to implement QoS once your VoIP system is set up

  1. Best Effort, 
  2. Integrated Services, and 
  3. Differentiated Services.

Best Effort Approach

A QoS paradigm in which all packets have the same priority and packet delivery is not guaranteed. When networks do not have QoS policies defined or when the infrastructure does not support QoS, Best Effort is used.

Integrating Service

An integrated service architecture describes the pieces required to provide QoS on a network. In this model, resources are assigned to the network based on demand-availability criteria.

Differentiated Services

Differentiated Services is a computer networking architecture that defines a simple and scalable technique for categorising and controlling network traffic as well as delivering QoS on contemporary IP networks. 

Instead of assigning the same amount of resources to all QoS requirements or doing it based on availability, this model classifies packets into different categories and assigns resources based on statistical behavior.


Prioritize VoIP Traffic

VoIP traffic requires a stable bandwidth; thus, even a small delay might cause a perceptible drop in call quality. 

Vigor Router supports VoIP prioritizing, which prevents VoIP packets from being delayed. 

When you activate ‘First Priority for VoIP,’ the router will allocate twice as much bandwidth exclusively for VoIP traffic. If bad quality is detected or there are two active calls, the router will additionally modify the allocated bandwidth.

Assign Traffic With a DSCP 46

A DSCP (Differentiated Services Code Point) header is used by many VoIP devices to indicate network traffic categorization. 

For example, the Differentiated Services Code Point (DSCP) header instructs network switches to honor high-priority traffic. If possible, configure both inbound and outgoing RTP packets with DSCP 46.

Set up Trust Mode with Strict Priority (If Supported)

A QoS approach in which network devices such as routers and switches are designed to support several types of traffic with varying priorities. Network traffic must be classified based on a company’s setup.

Voice traffic, for example, might be given a greater priority than other forms of traffic. Differentiated Services Code Point (DSCP) categorization is used to assign priority to packets. DiffServ additionally uses per-hop behavior to apply QoS methods to packets, such as queuing and prioritizing.

VoIP QoS Limitations

There is no magic solution for improving the audio quality of your VoIP business phone system. However, QoS is a vital performance indicator that will help you improve quality and boost both customer happiness and first-call resolution. 

Keep in mind that there are some limitations to consider when implementing QoS:

Regardless of the routing model, QoS is only one component of a larger system spectrum. As a result, your speech packets may travel through many routers and network gateways, which may have an impact on audio quality.

To install QoS for corporate phone systems, VoIP service providers must give ongoing support. As a result, there may be some early issues that need technical support or training sessions; nevertheless, QoS will provide amazing benefits in the long term.

VoIP QoS Best Practices

To improve QoS for wireless VoIP apps on access points, you need to follow these best practices.

  • Configure a Dedicated Voice SSID.
  • Select a compatible authentication mode
  • WPA2 is solely used for encryption.
  • 802.11r high-speed roaming.
  • Roaming on Layers 2 and 3.
  • On a Voice VLAN, divide traffic.
  • Choosing a Band


For most organizations, choosing a dependable VoIP service is a crucial step.  

QoS is an often-overlooked component of VoIP. Many businesses seek to deploy VoIP on a data network that has been running smoothly for years, only to discover that it is incapable of supporting VoIP as-is. 

Understanding QoS functionality is critical for effectively adapting the infrastructure for a converged network and enjoying all of its benefits and rewards.

Choose a team of experts that know the ins and outs of VoIP QoS to assure that your business phone system runs with the highest possible quality at all times.