So you want to measure audio quality… Is network monitoring the answer?

Audio quality can have a huge impact on customer experience and the performance of your contact centre.
On Tuesday 04 December 2018 by Mika Wilson

In this series on audio quality we’ve explored how much of an impact audio quality can have on customer experience and the performance of your contact centre, and also looked at the best measures of audio quality.

But what kind of monitoring tools can be used to take these measures?

Most large organisations have some kind of network monitoring in place to maintain the performance of their telecoms network. This can provide valuable information on the performance of data within your internal network, but can it be used to measure audio quality, as a customer experiences it?

The simple answer is no.

What does network monitoring show you?

Network monitoring is a valuable tool. It's great for monitoring uptime, downtime and performance of your internal network's:

  • Hardware
  • Data services

On its own, however, traditional network monitoring only takes into consideration what’s happening in your internal network. This leaves a huge blind spot for everything outside of your internal network. The telephone provider (carrier) in the country your customer is calling from, their partner providers…

International calls complete multiple hops from one carrier to the next, and are often routed through a number of countries before they reach their endpoint. This leaves a large stretch of the call path where audio quality issues can occur, and where network monitoring has no line of sight.

What network monitoring shows you:


How to truly measure a customer's experience

The only way to truly measure audio quality, as a customer experiences it, is by testing the full path of the call, from end to end. This means calling your contact number from the same country (and lines) as your customer would, allowing you to take a measure of audio quality that reflects the full path of the call and the real experience of your customer.

What number testing shows you:


Number testing reveals the full picture, from end to end. 

The audio characteristics measured by number testing (as listed in the table below) are revealed through using Perceptual Evaluation of Speech Quality (PESQ). This gives an objective score of audio quality which takes those factors into account by analysing a real audio recording, played through the full network from the country in question, through a real phone line to your contact centre.

Using an in-country server, connected to real phone lines, number testing can provide an accurate picture of the audio quality your customers are actually experiencing.

What factors can be measured?

Audio quality factors measured by network monitoring and number testing:

 Network monitoring Number testing 
 Latency within internal network  Connectivity
 Bandwidth  Audio sharpness
 Jitter  Background noise
 Packet loss  Audio interference
   Loss in volume
  End-to-end latency

The above table shows audio quality factors that can be measured through network monitoring vs true end-to-end testing of your numbers.

There are crucial aspects like loss in volume and sharpness that can’t be measured with network monitoring, but it’s also important to note that network monitoring can only measure data performance within an internal network.

So, while both options give a measure of latency, network monitoring refers to latency within the internal network. Latency (or anything else for that matter) occurring on the rest of the route between you and your customer will not be factored in. Number testing will measure latency of real audio across the whole path of the audio, including through the PSTN/mobile telephone network.

This is important because measures of the behaviour of data on your network can only be used to form an assumption of how audio is behaving. This, in turn, can be used to generate a mean opinion score (MOS) for the audio but it’s not a reliable, objective measure of the actual audio quality on your network.

So by all means, try to measure your audio quality using network monitoring, but be aware that the results will be unreliable, to say the least.


You need network monitoring - it's a crucial part of the toolkit to ensure your internal network's hardware and data services are operating efficiently and effectively.

But it won't give you the full picture.

If you want to find out what your customers' experience is when dialling your contact centre, then an accurate end-to-end measure of audio quality is required. And the only way to achieve this is by dialling your contact numbers in-country and using an objective measure such as PESQ.

Find out more

For a more in-depth look at the difference between network monitoring and number testing, read our whitepaper: How network monitoring is keeping you in the dark.

Do you want to talk to someone about how you might be able to use number testing to measure audio quality in your contact centre? Drop us a line