This can be a tricky issue to diagnose, particularly because their are many factors that could cause a slow down in your connection. Based on reports that we receive, the most common cause of a slow-down can be high throughput utilization. That is, their is perhaps more data flowing through your internet "pipe" than can be handled. This will often cause slow speeds and dropped packets
Other factors, such as light level issues on the fiber optic line, can contribute to this issue. Please contact us at 508-646-0030 and we will be able to check the line's statistics with an engineer to find any potential issues.
Assuming all in normal with the fiber optics, inspect your network traffic to find any systems that may be overutilizing available throughput. Such uses could be large backups runnings, simultaneous streaming and downloading, and more.