In order to assess the state of implementation of the AES67 Standard on High performance Streaming Audio-over-IP, the AES has organized a series of Interoperability testings (Plug Fests) in Munich (IRT, 2014), Washington (NPR, 2015), and London (BBC, 2017). This session will present the results as well as the progression in the overall interoperability between the plug fests. Specific issues that appeared during those event will also be highlighted: network setup, PTP, usual bugs and standard interpretation errors.