© 2018 IEEE. The internet had been considered as pre-dominantly human-to-human interaction. However, this is changing rapidly with the onset of 'smart' devices. The potential of a connected world is very much dependent on the adoption of the technologies to realize Internet of Things or IoT. IoT devices produces a unique set of challenges in which the current deployment standards, models technologies fall short. In this survey paper, the various architectures are explored including the newly introduced fog architecture. The challenges in the cloud based IoT architectures and the IoT paradigm are discussed and categorized. Furthermore, some of the identified solutions and future directions toward overcoming the challenges are described.