We propose an admission control approach for IPTV in which decisions to admit new flows are based on effective bandwidth estimates calculated using empirical traffic measurement. We describe our approach to estimate the effective bandwidth required to satisfy given Quality-of-Service constraints on traffic and specify a simple admission control algorithm which uses this estimation to manage flow admissions. We present the results of a simulation study, employing real traffic traces for long-lived flows, which indicate that our algorithm ensures that an adequate, but not overly generous, amount of bandwidth is allocated to ensure that Quality-of-Service targets for accepted flows will be met. We also compare our algorithm with alternative approaches based on analytical estimation of effective bandwidth; we demonstrate that these approaches are weak at taking into account related Quality of Service constraints and thus reserve inappropriate amounts of bandwidth, leading to either increas...