This paper examines techniques to embark upon the Quality of Service (QoS) issues in Wireless Body Area Network (WBAN) using the Constraint Application Protocol (CoAP) framework. The design of QoS in WBAN is a challenging task due to several reasons such as lossy channel, resource-constraint nodes and priority-based services. The QoS provisioning mechanisms mostly focus on the MAC layer and do not extend easily across all platforms. We propose to integrate the QoS design into the application layer using the standard CoAP framework. CoAP architecture is a platform independent standard intended to be used in simple electronics devices such as Internet of Things (IoT). We introduce three CoAP features such as Caching, Confirmability and Multicast addressing. We examine these options to deploy the QoS mechanism in the WBAN composed of sensors with heterogeneous priorities. The proposed solutions are universal and can be deployed on any sensor platform which supports the standard CoAP software protocol.