A method for controlling distribution of a content stream in a communications network, comprising the steps of: storing session state information about existing communication sessions within the network, receiving a request (15) for transmission of a content stream to a requesting network client (4), determining that an existing session includes the requested content stream, determining that a receiver (1) of said content stream in said existing session has a network location correlated with a network location of the requesting network client, selecting a relay network element (5) capable of servicing said correlated network locations, and setting up at least one communication session for streaming said requested content stream to both the requesting network client (4) and said receiver (1) of the content stream in the existing session through the relay network element (5).