We currently have a 4Mb/s fibre Internet connection, the Output on this interface is consistintley at the limit of the available bandwidth (please see the attached photo from the ASDM). We host our own website internally, so I know this is part of the usage. Does any one have some good tools they can recommend for monitoring what device(s) are chewing up all this bandwidth? Does the ASDM have any thing itself which can give me an indication of what to look at?
If you are running 8.0 or later you can use "threat-detection". If you enable the statistics of threat detection on the ASA then you can get the top talkers.
Here is the guide for your reference http://www.cisco.com/en/US/docs/security/asa/asa80/configuration/guide/protect.html
ASDM will also give you the top talkers in a chart in the Dashboard.
I hope it helps.