You may be getting occasional “down link” alerts that play the audio and change a link to white or black when the link is actually online/up.
If the device is slow to respond to SNMP queries, then TotalView displays an alert.
If it is white lines (not black ones), then the device is slow to respond to queries. You will want to monitor the other end of the link for status and utilization. The other end of the link may be quicker to respond to SNMP queries.
Also, Refer to this article http://support.pathsolutions.com/solution/articles/14000031086-map-giving-false-alerts