VoIP Quality Testing
Your Internet Connection
The current generation of VoIP software and devices are very responsive and user-friendly, but at the end of the day your call quality depends on the quality and speed of your internet connection.
Below are basic explanations of each network assessment test point that can affect your call quality:
Upload and Download Speeds:
Bandwidth speeds can vary widely based on your Local Area Network (LAN), your Internet connection (cable modem, DSL, T1, etc.) or your Internet providers network. In order to carry voice traffic over your Internet connection it may require you to upgrade your connection or in some circumstances change providers.
Delay occurs when there is a higher than normal latency on your network. Latency is the amount of time it takes between one person saying something and the other person hearing what was said. Latency doesn’t typically cause audio quality issues, but when the latency is over 150ms, the delay is noticeable to users.
Packet loss is the failure of one or more transmitted packets to arrive at their destination. This can cause noticeable effects in all types of digital communications. With audio calls, packet loss can provide jitter and silent gaps in communication.
Jitter occurs when voice packets arrive with varying delays. This is typically caused with changes in network traffic, and can usually be fixed by using Quality of Service (QoS), or reducing the amount of traffic on your network equipment is handling. Jitter is often reported as poor audio quality.
Quality of Service (QoS):
QoS is a feature available in quality managed network switches that allows you to prioritize your voice traffic. This allows you to ensure that your phone calls are going to get the bandwidth needed regardless of what else is happening on the network. QoS is a very important feature to quality and reliability of IP phone systems.
You can run a basic online simulation testing your connection for VoIP here:
If more extensive testing is required, Totalconnect Staff might ask you to use WinMTR (See Below).
How to install and use WinMTR on Windows
During troubleshooting for voice quality issues our Technical Support team may ask you to install and use WinMTR.
WinMTR is a powerful network diagnostic tool that enables users to diagnose and isolate networking errors and provide helpful reports of network status to upstream providers.
WinMTR can be installed on any Windows platform. Follow these steps to download and install the application:
- Go to http://winmtr.net/winmtr_download/ : the application will automatically start to download.
- Open your download folder and locate the winmtr.zip file. Extract the contents of this compressed file. The application does not require any further installation.
- There will be two folders created; WinMTR-32 and WinMTR-64.
Once you have uncompressed the application you can now run WinMTR. If you need you can copy this entire folder to another location or even another Windows based computer.
- Double-click on the appropriate folder for the Windows platform you are using. If you are unsure then use the WinMTR-32 folder.
- Right-click on “WinMTR” in the folder window and click on “Run as administrator“.
- You may be prompted by a User Access Control (UAC) dialog confirming that you wish to allow this application to run. Click on Allow or Yes. If you are asked to enter a password then you will need to enter a password of someone who is an Administrator for your computer. This may be your logon password or you may need to ask an IT administrator for assistance.
Generally we will ask you to run WinMTR to the Domain or IP Address of your Hosted PBX or to one of our host domains. Follows these steps to start the trace.
- Enter a value as instructed in to the “Host” field.
- Click on the Options button and changes the “Interval” value to be 0.3. Then click the OK button to close the Options page.
- Click the Start button to start the trace.
The trace will continue until you push the Stop button however at any time, even whilst the trace is still running, you can copy the results to the clipboard or export them.
For most issues we will ask you to run the trace for 30 minutes after which time you should email us the results in both text and html formats.
Basic Analysis of WinMTR Results:
Each row is a “hop” (step) in the path between the computer running WinMTR and the Host entered. This will include any internal hops, the hops within your internet service providers (ISP) network and the last hop should be the Host the trace is running to. If the Host is not listed last then this may indicate a connectivity problem.
You may find that some of the hops show 100% packet loss or read “No host response”. This may not actually reflect a problem but is more typically explained by the fact that the specific device is not responding to the ICMP packets that are being sent by the tool.
The two most important data points in the results are the columns called Loss and that called Avrg. The loss should be no more than 1%
The Avrg column shows the average latency (delay in packet transmission by the network/node) and it should not exceed more than 150 (which equates to 150 milliseconds) for any hop.
If the results show “No raw socket found” or “Unable to get the raw socket” then this indicates a local problem with the computer running the trace.
- Ensure that you are running that application using the “Run as Administrator” option as detailed above.
- Some firewall and Anti-virus software can impact the trace. Try disabling the firewall and security software for a brief time to collect the trace then re-enable it afterwards.
- It is recommended that you close all other applications and/or perform a full reboot of the computer to ensure that no lingering processes are impacting the trace.
This article is intended as a guide only. The information in this article was correct at the time the article was last updated. Differing product versions may cause variations to the instructions. Totalconnect reserves the right to make any modifications without prior notification.