I. Introduction
All over the world, IP-based physical security products such as IP network camera (IPNC), Network Video Transmitter (NVT), Network Video Display (NVD), Network Video Storage (NVS), Network Video Analytics (NVA), and so on, has been flourishing. In order to provide interoperability among IP-based physical security products regardless of manufacturer, ONVIF (Open Network Video Interface Forum) has been founded in 2008 [1]. In this paper, we present our efforts on developing an ONVIF Event service.