You can do some customization within Contact Center Client, specifically add a Marquee. This will allow you to display a summary showing the number of queued calls and/or the longest queued call, and then change the colors of that marquee depending on call counts/timers, as well as play an audio file when an alert threshold is reached. If the agents or supervisors are using desk phones on a MiVoice Business, you can also add group alert keys to the phones that will display queue state and chirp if a threshold is reached.