Troubleshooting Sell Voice problems

all Sell plans

All calls from Zendesk Sell are VOIP (Voice over IP) calls. Call quality can be dependent on internet connection, your microphone or headset, and general service load.
In order to ensure the highest level calls, here are some actions you can take:

  • Use a wired internet connection whenever possible
  • Avoid placing calls when connected to free/public wifi as the connection can be unreliable
  • Use a headset with a noise-canceling microphone rather than your computer's microphone/speaker

For optimum voice quality, we recommend that you use Google Chrome as your browser on a high-speed, low latency Ethernet or Wireless connection.

Setting up the network for best results 

Voice uses Twilio to provide our VOIP services. In order to provide Voice, your browser establishes a connection to Twilio on these addresses and ports: 

Component Address Client-side port used Server-side port used Protocol
Signaling Any 443 TCP
Presence Any 443 TCP
RTP A dynamic IP pulled from Amazon’s public range Any 10,000 – 20,000 UDP

You can find Amazon's dynamic IP range on their forums.

For client-side ports, most machines select from the ephemeral range of ports 1,024 to 65,535.

If your router supports Quality of Service (QoS) settings, use these to prioritize port 443, along with the IP addresses of the computers you use to make Voice calls. If your router's QoS settings are fairly simple, use them to prioritize all SIP traffic in order to give Voice priority over most other things on your network.  

Troubleshooting suggestions

If you are still having problems, here are some potential solutions:

Browser cannot establish a call

  • Check that your browser is not restricting access to your microphone or headset. If you are using Chrome, you can check this from Settings > Advanced > Content Settings > Microphone. Make sure "" is in the "Allow" list. If this option is listed as "Block", click the X to delete it from the list. Removing this entry will allow you to grant Zendesk Sell a new connection the next time you go to place a call.
  • Check that the ports in your router and firewall allow for Voice traffic. For more information on this, view the chart at the bottom of the article.

One-way audio

  • Confirm that your headset and microphone are correctly connected to your computer.
  • Check that the correct output and input for audio are selected in your computer's system settings.
  • Ensure that any hardware mute buttons are not enabled.

Call audio is garbled

  • Try using a headset with your computer instead of the default built-in microphone
  • Reduce ambient noise nearby.
  • Ensure your computer has enough resources available to process a call - make sure that your RAM and CPU are not over utilized. Close any unneeded applications and tabs.

Audio drops out

  • Check your network speed and latency from Pingtest. The test will give your network a letter grade. Work with your network provider or IT team in order to bump your network quality to an "A" grade.