Network Requirements
Try having a minimum of 16kbps per agent per call.
You can gauge your network connectivity using any of the best recommended online speed test services
Best Practices.
Network connectivity:
We recommend using Ethernet rather than WiFi, because, the wireless medium is susceptible to packet loss and can affect the call quality (such as one-way audio issues & distorted audio).
If you can reduce the number of devices operating on the same channel, you can reduce the packet conflicts.
Avoid data transfer, downloading of huge files, video streaming, etc over the same WiFi network (Voice network) because such tasks can increase latency.
To avoid latency in media processing(audio packets), network traversal(NAT, STUN & TURN), etc. please use an internet connection with high bandwidth.
QoS:
If you have ensured that all the above factors are considered and maintained properly so as to carry through a network in good condition for voice calls and continue to have audio quality issues on your voice calls, you might consider configuring the network router with QoS rules to prioritize the UDP packets. Useful link: setting up QoS for VoIP
Mic:
Please test the microphone before starting to use the same for calls. You can use a 3.5mm headset or Bluetooth headset as per the compatibility of the browser and the device you are using to make calls/receive calls.