Software Defined Networking (SDN) is supposed to bring the dynamicity and automation to today's network through a logically centralized network controller. It improves automation and management by virtue of a set of application programming interfaces (API)s organizing its northbound interface (NBI). Structuring the NBI remains however one of the main SDN challenges. In this paper we show that any implementation of the NBI requires at least push and pull capabilities. We argue that XMPP could be the best candidate to satisfy these requirements. It provides a tight integration between client-side network applications and the SDN platform by the help of its intrinsic asynchronous capabilities. We show that the overhead and delay costs of this approach are constant.