80% of voice quality issues are the result of the end user's internet connection. High quality voice conversations require an extremely consistent (low jitter) connection to our servers. To isolate possible problems, we recommend network administrators download Colasoft Ping Tool https://www.colasoft.com/download/products/download_ping_tool.php and setup a continuous ping to 1. our T-Max and 2. a constant server like google.com. Poor voice quality caused by the network will manifest itself in any packet loss in excess of 1%. T-Max recommends always using a WIRED (not Wi-Fi) always-on connection like Fiber or Broadband Cable. In certain situations where the internet connection is being shared it might be necessary to implement VoIP QoS on your router. Please consult your network administrator for further instructions.
Please make sure your modem and its firm ware are up to date. Make sure your modem is a Gigabit capable modem (contact your ISP to determinate that.) (ISP-Internet Service Provider)
Make sure all your switches are 10/100/1000 and are not daisy chained https://answers.yahoo.com/question/index?qid=20110301032328AAVlRsV.
