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How Much Bandwidth Does VoIP Need for Quality Connections?

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So, you’re considering using a VoIP phone system for your business? Maybe you already have a VoIP phone system, but you’re struggling with poor call quality. Either way, it’s crucial that you ensure that you have the right bandwidth available for your VoIP needs. Simply put, because bandwidth has a significant impact on your VoIP call quality, it’s the only way you’ll ensure high-quality calls.

But how much VoIP bandwidth do you need? In this post, we’ll look at this question a bit closer and also give you some other tips you can use to improve your VoIP call quality.

Did you know that businesses that use VoIP phone systems can save as much as 90% on their startup costs?

How Does Bandwidth Affect VoIP?

To understand how bandwidth affects VoIP, it’s important to first recap a few important concepts. Firstly, we should look at what bandwidth is. Many people incorrectly assume that bandwidth refers to the speed at which data is transferred.

However, even though it’s expressed as speed, bandwidth actually refers to the capacity capability of the network. In other words, it is the maximum amount of data the network can transfer during a given period of time. It’s measured in either bits per second (bps), kilobits per second (Kbps), or megabits per second (Mbps).

Now that we’ve recapped what bandwidth is, the next thing we should look at is how VoIP uses bandwidth. VoIP uses a series of codecs to compress and decompress data, which allows the voice data to travel from one point to the next over the internet.

And because VoIP relies on the internet to provide voice services, its performance and quality are directly correlated to the amount of bandwidth you have available. Also, keep in mind that VoIP will typically also compete with other online services for bandwidth.

Now that we’ve recapped why bandwidth is important for VoIP, the next question is: What is the recommended VoIP call bandwidth? To answer this question, there are a few questions, you’ll need to answer:

  • How many phone lines do you need?
  • How many calls will you make or answer concurrently?
  • What other applications that use the internet will you use with the VoIP system?
  • What are the upload and download speeds offered by your internet service provider?
  • The codecs provided by your internet service provider?

Once you’ve answered these questions, you’ll have a general idea of the voice over IP bandwidth you’ll need to ensure your VoIP phone system provides good call quality. Generally, though, you’ll need about 85 – 100Kbps for every concurrent VoIP connection.

How is VoIP Bandwidth Calculated?

Based on the above, to calculate the VoIP bandwidth or the internet speed for VoIP you’ll require, you’ll multiply the number of concurrent VoIP calls by 100Kbps. However, this is only the minimum because, as mentioned earlier, the required bandwidth will be affected by other services or applications you use. With that in mind, here are the minimum and recommended voice over IP bandwidth requirements.

Number of Concurrent CallsMinimum Bandwidth RequiredRecommended Bandwidth Required
1100Kbps upload and download3Mbps upload and download
3300Kbps upload and download3Mbps upload and download
5500Kbps upload and download5Mbps upload and download
101Mbps upload and download5 – 10Mbps upload and download

Apart from VoIP internet speed, when determining the bandwidth you need, you’ll also, as mentioned earlier, need to consider the codec your internet service provider provides. These codecs can have a significant impact on your VoIP call quality. Here are the different codecs ISPs typically provide.

CodecBitrate per secondBandwidth requiredDescription
G.7298Kbps24KbpsImplements extreme compression, which makes it a good option for low bandwidth.
G.71164Kbps80KbpsOffers lossless compression that reduces bandwidth requirements. Can also be used for fax services.
G.72248 – 64Kbps80KbpsOffers high quality but, as a result, requires more bandwidth.
G.72616 – 40Kbps56KbpsUsed in international trunk services.
G.72816 Kbps32KbpsOffers toll voice quality at lower bandwidths.

Other Tips to Improve Quality VoIP Connections

Apart from ensuring you have the right amount of bandwidth based on the number of concurrent calls you make, there are other ways to improve VoIP call quality. Here, some tips include:

  • Monitor Call Quality. Apart from bandwidth, there are many other reasons why you might experience call quality issues with your VoIP service. As such, you should monitor your call quality, which enables you to identify any issues proactively before they have an impact on your business.
  • Upgrade Your Router. If you’re using a basic VoIP router, it might be worth your while to upgrade to a more advanced model. Apart from helping you sort out call quality issues, it will also provide you with more advanced features, some of which we’ll deal with later.
  • Use a jitter buffer. An advanced router can allow you to implement a jitter buffer. It smooths out packet distribution by collecting, storing, and sending packets over the internet at even intervals. Even though this could add a slight delay, it improves call quality.
  • Configure Quality of Service (QoS) settings. You can configure your QoS settings to prioritize any VoIP traffic when there’s a heavy load on your internet connection. This means VoIP traffic will be sent first before other traffic like web pages or emails.
  • Segment traffic with a VLAN. Another option to prioritize your VoIP traffic is by setting up a virtual local network or VLAN. This allows you to set up a number of devices that will share a specific connection and, as such, enables you to segment your VoIP traffic to achieve the best call quality.
  • Convert to ethernet. When you have constant issues with your VoIP internet connection, you could also consider switching to ethernet. It gives you a more stable and reliable connection compared to Wi-Fi.
  • Switch off other wireless devices. Other wireless devices, including Bluetooth devices, can affect your internet connection. You should thus consider switching off any wireless devices you’re not using.
  • Use quality headsets. If you’re using headsets in your business, you should consider upgrading to high-quality headsets, as this can help you eliminate many call quality-related issues.

When businesses move to a VoIP system for their communication needs, they can save up to an average of 32 call minutes per day.


VoIP offers several benefits from increased flexibility and scalability, more advanced features, improved reliability, and significant cost savings. However, if you want all these benefits, it’s crucial that you have enough bandwidth available. If not, your call quality will suffer, and you’ll lose out on many of the other benefits. Hopefully, this post showed you how much bandwidth you need for optimal VoIP usage.

To take advantage of all the benefits that VoIP offers, have a look at ULTATEL’s cloud-based phone systems. It’s the scalable, cost-efficient, and reliable solution that unifies the way your team and customers communicate.

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