The data usage should be correct. If you are talking about the traffic graph, the spikes may not accurately reflect bandwidth usage, but over a long period the average should be correct. To graph the rate, sonar takes the bytes in and out counters from RADIUS and compares them over a certain period. I don’t know what period it uses and would like to know as well, since it seems imprecise - I believe it sometimes assumes that x bytes was transferred over a shorter time period than was actually the case, resulting in spikes that go twice where they should with no traffic before. ex. if the customer downloads 10Mbps constantly over a half hour, you might have it graphed where you see 0Mbps for 15 minutes and then 20Mbps for 15 minutes. It still averages out so that the usage tracking is correct, but the spikes are confusing.