If you are having problems with voice or video quality this could be related to your internet speed, check your speed with a online tool, we recommend Speedtest by Ookla, https://www.speedtest.net/.
After you have run the test please see you meet the bandwidth requirements below:
Voice:↓ ↑ For audio VoIP calls – 30Kbps to 134Kbps upload and download
Video:↓ ↑ 2.0 Mbps upload and download for one screen
Video:↓ ↑ 2.0 Mbps upload 4.0 Mbps download for two screens
Video:↓ ↑ 2.0 Mbps upload 6.0 Mbps download for three screens
Share:↓ ↑ For screen sharing – 150 to 300kbps upload and download
If your bandwidth is fine then please check your firewall and see if it meets our requirements.