How to troubleshoot Voice Quality Issues - With a Premise Phone System and Local Phones
If you are sending calls out your internet connection using VoIP you are prone to audio quality issues. These audio quality issues can be caused by a number of different factors that often times are very hard to diagnose. The following dependencies exist for good audio quality.
If your phone system is onsite the call passes through the following equipment:
- Network Switches
- Phone System
- Network Switches
- Cable Modem (or ISP Equipment)
- VoIP Provider
- VoIP Providers Network
- External Carriers Network
It is critical to identify if the issue is internal to your network or external with your ISP or VoIP Carrier. This can be easily identified with the following tests. The list above contains check boxes so you can check each item off as you have eliminated it.
Phone, Switch and Phone System Tests
To test if your phone, switch and phone system are processing calls clearly
- Dial *97 or hit your voicemail key.
- Dial another extension on the system that is in the same facility.
- If both of these tests produce good audio quality you can safely eliminate the Phone, Network Switches, and Phone System as a source of the problem.
Run a VoIP Quality test:
In order to run this test, open your local web browser and go to http://vac.visualware.com. Once there, click on the geographical dot closest to your physical location:
When you do, the site will check for the 'BCS Connector' required to conduct the test. If it is not installed, you will be prompted to download and install it. Once you have successfully installed the connector, refresh the page in your browser. If the installation was successful, you should see green text in the top right corner of your browser indicating the site detects the connector:
You will now need to click on the dot on the map closest to your physical location again, at which point the test will start running:
Once the test completes you should see output similar to this:
All of this information is valuable in regards to the quality of your connection; pay specific attention to the results from the 'VoIP Jitter', 'VoIP Packet Loss', and 'VoIP MOS' tests.
- You are looking for a MOS score above 3.0 (4.5 is the best). Take a screen shot of the test audit and email it to email@example.com if you need assistance analyzing the results.
- Good Results: No items in Red on the test audit generally means your network and Internet are in good shape. The issue is likely with your VoIP Provider or your Internet providers IP route to your VoIP Provider.
- Bad Results: If you are seeing any items in red you are likely experiencing network or internet issues, continue testing to try isolate the source.
Next we need to identify if your Router, Modem or Internet Connection is the source of the problem. To do this we will use an application called Ping in a command window.
Instructions to open a Command window and run Ping
- On a windows machine go to start -> run -> command or on windows 8/10 just hit the windows icon and start typing command.
- This will bring up a window like this:
- From within this window let start a ping to the phone system. Type ping -t xxx.xxx.xxx.xxx where the x's represent the IP for the phone system. When done control+c will stop the test. Run the test for at least 10 min unless you are seeing issues right away.
- We are looking for ping times that are fairly consistent and no dropped packets. If they are jumping around more than 100 MS those will result in audio drops.
- It is best to run this test from a hard wired computer, wireless will have it own latency. It is even better if you run the test from the switch port on the back of the phone that is having the issue. The below results show a network that has bad audio quality due to packet loss.
Run through the following scenarios to isolate the problem with your ISP, Router or Cable Modem
- Run a ping test directly to your phone systems IP as instructed above.
- Simultaneously, open another command window and run a ping to google: ping -t www.google.com.
- Let the test run for awhile 10+ minutes or until you see clear results.
- End the test with control+c
- If pings to your phone system pings look good yet pings to the internet show issues you must now identify if your router or network load are an issue.
- Good Results: If both tests look good i.e 0% loss and Minimum and Maximum ping times within 100 ms you can skip the next test. You should call your VoIP Provider to open a trouble ticket.
- Bad Results: Run ping tests directly from your internet network port on your cable modem. You will need to disconnect network traffic to your network.
- Next plug your computer directly into your cable modem and run the same ping test to the internet. This test is to isolate that your router or network load is not the source of your issues.
- Good Results: The issue is likely with your network router switches or QOS settings on your router. Your ISP seems to be performing well with no load on it.
- Bad Results: This is pointing to your ISP as the source of the issue. Call your ISP and report the problem to them.
Run through the following scenarios to isolate the problem with VoIP Provider
- The easiest way to isolate your issue to a specific VoIP Provider is to register a second VoIP Provider to your system. If you are not using Intuitive VoIP as your VoIP Provider we would be an ideal choice as we have no commitment and great rates. Call or email us to learn more
- Run tests through a second VoIP Provider to see if the audio issues are present.