Unified Communications as a Service (UCaaS) is a delivery model in which PBX (Private Branch Exchange) and collaboration applications and services are outsourced to a technology provider and delivered over an IP network, typically the public Internet.  It’s being driven by growing desire to eliminate onsite hardware that require maintenance contracts and ongoing management costs, as well as a great need for redundancy to mitigate costly outages.  It enables a uniform telephony experience for all users, regardless of location, due to the availability of affordable bandwidth.   When voice and telephony are integrated with conferencing, email, and instant messaging, more and more efficiencies emerge in every interaction.