This paper presents a novel application-aware network architecture for emerging IT services and future Internet applications. It proposes and analyses network architectures that integrate Session Initiation Protocol (SIP) with Optical Burst Switched (OBS) network technology in a unified manner. It demonstrates that the proposed SIP-enabled OBS network can be used to manage application sessions and provide network and IT services according to the application requirements. Furthermore, various SIP over OBS layering architectures, utilizing a number of end-to-end resource discovery protocols (both for network and non-network (IT) resources) are presented and analyzed. Finally, this paper reports on the validation of functionalities, mechanisms and protocols for the proposed SIP-enabled OBS network, from the node level to the network level, through a test-bed demonstrator.