If you experience issues with call quality during a call, please check the following.

1. Check the network load

• a. Try a different network from the one you are currently using
  • For example, wired LAN, wireless LAN (Wi-Fi), etc.
• b. Run a speed test to check whether the network quality meets the recommended internet connection requirements
  • Compare the results when the issue occurs and when it does not occur
  • If network access has increased due to an increase in personnel, etc., a bandwidth issue may also be the cause

2. Check the computer's load

• a. If you have many applications open, close the ones you do not need
• b. If you have many browser tabs open, close the ones you do not need
• c. Check whether any application other than MiiTel is communicating over the network
  • If it is, check whether stopping it improves the call quality
• d. Check whether you are running any processes that place a heavy load on your computer
  • Check whether any process is running in the background

3. Check the browser version

• Check whether the browser you are using is up to date
  • If it is not, update it to the latest version

4. Check the headset

a. For wired connections

• 1: Try replacing it with a different headset to see if the issue improves
  • In some customer cases, the issue was caused by a faulty earphone
• 2: Without using the headset, try the computer's built-in speaker and mic

• 3: Check the connection between the computer and the headset for wear or damage
• 4: Unplug and reconnect the headset
  • If there was a call quality issue during a call, unplugging and reconnecting the headset may resolve it

b. For wireless (Bluetooth) connections

• 1: Try replacing it with a different headset to see if the issue improves
  • In some customer cases, the issue was caused by a faulty earphone
• 2: Without using the headset, try the computer's built-in speaker and mic

• 3: Disconnect any other Bluetooth devices that may be causing interference
• 4: Try a wired headset

5. Check the network status and connection stability

a. Check the router and other network equipment

• 1: Unplug the router and reconnect it
• 2: If the router's power is connected through a power strip, connect it directly to a wall outlet
  • Insufficient power supply to the router can cause unstable operation
• 3: Avoid a congested router and connect to a different one
• 4: Check whether the NAT table capacity is insufficient
• 5: Check whether your router or network device has sufficient NAT session capacity
  • This helps prevent the NAT table from refreshing too frequently
• 6: If you have multiple routers, check whether double NAT is occurring
• 7: Check whether QoS settings are available through your router or other network equipment, such as a UTM

b. Check the VPN connection

• 1: Check whether the VPN connection is being turned ON/OFF during a call
  • Switching the VPN connection during a call may affect the call
• 2: Check whether the VPN connection is unstable
• 3: In MiiTel Phone, configure voice communication during calls to bypass the VPN (turn off the VPN) and check whether the voice quality improves

c. Try enabling the setting to force the use of TCP port 443

• In MiiTel Phone, enable the setting to force the use of TCP port 443 and check whether the call quality improves

6. Check the MiiTel Phone mic settings

Open the MiiTel Phone audio settings screen by following the steps below.

1. Launch MiiTel Phone.
2. Click [Menu] > [Settings] > [Audio].

3. The speaker and mic settings will be displayed.

   

For the mic settings, change them in the following order and check whether the voice quality improves.

• Untick item 1 and check
• Untick items 1 and 2 and check.
  • If echo is a concern, untick only item 2 and check
• Untick items 1, 2, and 3 and check
  • If echo is a concern, untick only items 2 and 3 and check
  • If noise is a concern, untick only items 1 and 3 and check
  • If both echo and noise are a concern, untick only item 3 and check

7. If the user's voice stops reaching the other party during a call

Placing the call on hold and then resuming it may restore the connection.