We are often asked about the quality of mobile clients, and the complaints are not about the software itself, but about the quality of the call when connected via the networks of mobile operators. Warn about this is not the best and not guaranteed channel - it is useless. So - the task is to test the channel of the mobile operator before connecting.

Quality criteria

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Qualitative assessments of the type of good or bad are usually used to assess voice quality, but besides the qualitative description it is convenient enough to use quantitative methods to express the assessment in numerical form. Such an assessment exists and is called Mean Opinion Score (MOS) averaged assessment of speech intelligibility. MOS gives a numerical representation of the quality of the transmitted media after compression using codecs and transmission over communication channels.

It is expressed by a numeric value from 1 to 5, 1 is low quality and 5 is the best. MOS is quite a subjective assessment, as it is based on the perception of voice quality by people. However, there are applications that can measure MOS and such data is more objective.
Values ​​do not have to be integers, they are usually expressed as decimal numbers. For example, a value from 4.0 to 4.5 corresponds to quite acceptable quality for PSTN and VoIP, if the service reaches this level it can be considered quite decent. Values ​​below 3.5 are unacceptable for many users.

The second way to assess the quality of sound is R-Factor, it has a more extended scale from 0 to 120, which allows you to make a more accurate assessment. R-Factor is calculated based on user experience and objective factors that affect the overall quality of a VoIP system, network R-Factor and user R-Factor are calculated separately.

It is logical that you need to find quality measurement tools for each of the platforms for which 3CX develops customers. These are Android, iOS and Windows (we’ll leave the MAC alone).

3CXPhone for Android

For those who are not familiar with 3CX Phone for Android - a small video.



We look at the status of the channel in principle through Speedtest.net

Voiptester: Network Test Tool

The first test subject is 10K downloads.



It tests the network from the device to some of its server.
Pros - no settings.
Cons - does not give recommendations on voice quality.
By the way, a very large discrepancy with the speedtest.

Voip tester free

Only 1 thousand downloads.



First you need to register on the PBX (in the profile we enter the server, login, password, port)

Testing goes in 2 stages. The first is registration. For the second, you need to enter the internal number, the application will call it, pick up the phone and talk for a while. Based on this, quality assessment is in progress.
There are several reports.

Voice quality



Used strip



Jitter



Despite the fact that neither the MOS nor the R-Factror application counts, it does exactly what it needs - it watches the channel to our IP PBX.

SIP VoIP Checker

500 downloads.

The application works on our PBX, because first you need to enter the address and authentication data.



The first test checks server availability, DNS records and NAT type.



The second one tests all audio transmission protocols, UDP, TCP, TLS and other



Total - useful thing, but does not measure what we are looking for.

Next, we consider applications for iOS and Windows.

Download 3CX Phone for Android on Google Play https://play.google.com/store/apps/details?id=com.tcx.sipphone12&hl=en

Please note that 3CX Phone works only with its PBX 3CX Phone System for Windows .