We present models for performance analysis of IPTV services. The main topic is to model the interplay of the restricted number of channels, the larger number of available programs to be transmitted over the channels, and the concurrent access of many users to the same program, resp. channel (multicast services). In a simple Engset-like model we compute loss probabilities avoiding to count the number of concurrent users in the system. With a more detailed model where we explicitly count the number of concurrent users for the active channels we show how to compute revenue for the provider and loss probabilities as well. This model can be considered as a stratified system of different queueing systems. The main results are in both cases expressions for steady state distributions of simple structure, indicating separability.