Disclosed is a Quality of Service (QoS) control mechanism for QoS-aware network applications running on computer devices. The mechanism provides IP socket-based QoS Application Program Interfaces (APIs) for QoS-aware applications for accessing MAC layer QoS function of network access devices. In various embodiments, the QoS mechanism utilizes QoS API over Socket (QAoS) handler and/or a MAC layer QAoS handler wrapper at the network access device to control and monitor the QoS data being transmitted by the application over the active network interface(s).