A method, computer program product, and computer system for inferring quality of unified telephony calls based on real-time bi-directional exploitation of a full reference algorithm. A client copy of an audio file may be received from a client device associated with a unified telephony call. The client copy of the audio file may be compared to a local copy of the audio file using a reference algorithm. A quality of service associated with the client device may be determined based upon, at least in part, a difference between the client copy of the audio file and the local copy of the audio file.