Network neutrality is the topic of a vivid and very sensitive debate, in both the telecommunication and political worlds, because of its potential impact in everyday life. That debate has been raised by Internet Service Providers (ISPs), complaining that content providers (CPs) congest the network with insu cient monetary compensation, and threatening to impose side payments to CPs in order to support their infrastructure costs. While there have been many studies discussing the advantages and drawbacks of neutrality, there is no game-theoretical work dealing with the observable situation of competitive ISPs in front of a (quasi-)monopolistic CP. Though, this is a typical situation that is condemned by ISPs, and, according to them, another reason of the non-neutrality need. We develop and analyze here a model describing the relations between two competitive ISPs and a single CP, played as a three-level game corresponding to three di erent time scales. At the largest time scale, side payments (if any) are determined. At a smaller time scale, ISPs decide their ( at-rate) subscription fee (toward users), then the CP chooses the ( at-rate) price to charge users. Users nally select their ISP (if any) using a price-based discrete choice model, and decide whether to also subscribe to the CP service. The game is analyzed by backward induction. As a conclusion, we obtain among other things that non-neutrality may be bene cial to the CP, and not necessarily to ISPs, unless the side payments are decided by ISPs (through a non-cooperative game).