Implementing streaming service in vs2013

Asp.net c# project on vs2013Implementing streaming using js on client and asmx service calling streaming APIThe issue faced is finding a workaround using await and not using .wait We are receiving stream from api and also have implemented streaming between client and asmx serviceWe are stuck in fetching real time data and passing to js but our implementation waits for long running api to execute completely and then streams which defeats the whole purpose of streaming