All graphs are the daily 1 minute average, 0 means midnight. The COMM-T3 has a maximum capacity of 30 Mbits/second each way. Notice each graph is in a different scale.
Excessive traffic on one subnet may be going to or coming from a point on campus, but if you see a spike that corresponds to a spike on the T3 graph, you can be sure it's going off-campus.
Subnets with excessively high outgoing traffic (remember, the graphs are on a best-fit scale) are the ones who cause a problem for us.