You would need to look at a couple of things to see if the traffic is dirty and then to clean it up...
Look at the System > Traffic page and click on the servers and see how many Unprocessable Files there are or other errors that might be happening. If there are a lot, then you may have too much or dirty traffic.
Also look at the amount of traffic you are seeing on EACH monitor. There is a limit to the amount of traffic they can handle.
You can also do a WireShark packet capture on the Tap/Span port on the monitor. Then look at the capture, make sure there aren't any duplicate packets and the amount of traffic is manageable.
If you have dirty traffic, you will need to configure the TAP/span port to not send duplicate traffic or unwanted traffic.
There are tools that you can get from Symantec to help look at it too.
I have attached a couple of items that will help with tuning and analyzing the packets.
If this solves your questions please marked as solved.
Ronak