RAS entries missing from Event Viewer?

Our dial-ups come through a Cisco router and are authenticated on one of 3 BDCs in the building. It seems the dial up connections are not listed in event viewer’s security section…and for entries where we know an employee dialed in at a specific time, it lists the entry as Anonymous or shows a workstation ID they use when in the building…? Strange…does anyone have an idea what’s going on and how to corect it? Thanks in advance!