Method and apparatus for monitoring transmission characteristics in a network

A method for monitoring transmission characteristics in a network comprising a media client (100), a media server (200), and a data processor (250), the method comprising: establishing (300) a connection with said data processor (250); establishing (310) an end-to-end encrypted channel between said media client (100) and said data processor (250) for exchanging streaming media content over said connection; sending (320) a probing message to said data processor (250) over said channel, said probing message carrying a first timestamp indicating the sending time of said probing message; receiving (330) a response to said probing message from said data processor (250), said response carrying a second timestamp indicating the arrival time of said probing message at said data processor; and deriving (350) latency information, including an upstream latency between said media client (100) and said data processor (250), from a difference between said second timestamp and said first timestamp.