By combining on-premise and cloud in one PBX cluster you create a high level of resilience and recoverability for all telephony services.  With HAast you can place one node in the cloud of your choice (eg: AWS. Azure) and one on-premise to benefit from low cost and low latency when the on-premise node is active, and guaranteed connectivity with the backup node in the cloud is active.  Just one of the many ways HAast enables highly flexible, powerful, and fault tolerant communications.  HAast now includes support for scaling groups and guest movement across availability zones without change to license (only for AWS and Azure).