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Troubleshooting Call Quality Issues

posted Sep 30, 2015, 8:58 AM by EZvoip Co   [ updated Nov 20, 2015, 9:46 AM ]
We will address here mostly outgoing call issues, as we are assuming incoming call issues to be resolved. Choppy sound, especially when only for the outgoing part of the conversation, is almost always due to a local bandwidth or router problem. 

Kindly take the following steps if encountering choppy sound or other issues.
  1. Reboot the router and the telephony device (i.e., the device with the softphone or the ATA).
  2. Do a long-running ping to a reliable server (e.g., ping -t), and see if you get consistent numbers. Try also
  3. Try a different server. The incoming calls are tied to one server, but you may use any server for outgoing calls.
  4. Try a different softphone or device. If using your smartphone, try to use your Data connection rather than WiFi (or if you have been using Data, try using WiFi).
  5. If available, try using a different Internet connection and see if the problem persists.
  6. Go to, measure your speed and share the result with us.
  7. Call the echo number at 4443 and see if you can reproduce the problem while varying certain parameters within your control, such as other devices connected to your router, wi-fi on and off, etc.
  8. Try enabling and successively disabling different codecs.
  9. Set up QoS on your router. If it was already enabled, try disabling it (some router manufacturers have buggy / non-working implementations of QoS).
  10. Use a wired connection to your router if possible. Disconnect all devices connected to the router other than the device with the softphone or the ATA, turn the Wi-Fi off so that uninvited guests are not using it and wait a few minutes to let bittorrent or other similar bandwidth hogs to die down. Turn off QoS if enabled. Try making a phone call. If it is fine, then the problem is bandwidth and can be resolved by setting up QoS for UDP.
  11. Old router. Some older routers do not work well with VoIP. Users seem to have more problems with Dlink routers in particular, while Tomato firmware routers seem to be best.
  12. ISP reputation. Some ISPs are known to throttle connections and if they have a VoIP offer of their own, they might selectively throttle their competitors. However, this is unusual.
  13. Try the premium route by dialing 044 before the country code. We have numerous clients who have been using the value route with no issue; however, if you find that this works, even for specific destinations only, please let us know.
  14. Echo or delay (high latency). A poorly configured Internet connection (such as going through several routers) may sometimes cause high latency, which introduces a perceptible delay in sending voice data, causing the parties to a phone conversation to have to wait or find themselves talking over one another. If you find yourself in this situation, try switching from a softphone to an ATA plugged directly into the router. If that is not an option, test with a different network or Internet provider. There is a great variance among Internet access quality, which is out of our control.
We generally start troubleshooting on our end as soon as we learn of a problem. Knowing that you have gone through the above steps will greatly help us in identifying the issue, if it is an upstream network problem.