The next generation communication networks are going to be composed of virtualized node and link resources, which can be divided into various slices. Different virtual network slices can be configured with different amounts of resources so that each slice can be able to optimally satisfy the quality of service requirements of the given category of Internet of Things services. Virtualized resource allocated to slices can be dynamically adjusted to adapt the network capability to varying workload. In this article, we present our ongoing research on autonomous mechanisms for the intelligent allocation and dynamic adjustment of resources to make the virtualized network system scalable while optimally utilizing the resources. We present mechanisms for achieving three types of scalability: vertical scaling by adjusting virtualized resources allocated to a network function within a node, horizontal scaling by adjusting the number of virtualized network nodes and servers, and internetwork scaling by the arbitration of limited resources among many network slices. The preliminary performance evaluation results are also discussed.