There is provided a method of controlling a rate at which content data is received at a receiver over a network, wherein the receiver has caused a first strew of real-time communication event data to be received at the receiver, and a second stream of content data to be received at the receiver, the method comprising steps of: dynamically measuring network conditions of the network based on the real-time communication event data; and limiting the rate at which the content data is received at the receiver based on the dynamically measured network conditions.