In Gartner's Magic Quadrant for Unified Communications, one comment of note was that "service providers (such as the telcos, Google, et al.), were not included ... because they do not offer an on-premises solution." Gartner does not consider UC solutions in the cloud as "Unified Communications" per se, rather they consider those to be "UC-as-a-service (UCaaS)” solutions and publish a separate Magic Quadrant for them.
I empathize with Gartner's need to segment the two, as they admit that UC "remains a daunting and confusing topic." They agree the term is often misappropriated for marketing purposes, which creates more confusion. That said, a true UC solution will eventually be a blend of some premises-based components (which Gartner calls UC) and some cloud-based components (Gartner’s UCaaS).
Gartner cautions its audience that not everything vendors call "unified" can truly be integrated with third party solutions into a complete, end-to-end solution. Such "mislabeled products," as they call them, "are capable of being used only in a standalone and nonintegrated manner."
In my opinion, communications will only be unified when premises-based providers and the service providers work hand in hand to create end-to-end solutions for their mutual customers. Technologies like IMS (IP Multimedia Subsystem) in a network provider's core is something that premises-based vendors can leverage to do things that no premises-based vendor could do on its own. Combine that with QoS from a service provider's MPLS connections (whether in the form of SIP trunking or not) and you truly are talking about UC.
So, as Gartner highlights, complete, end-to-end UC portfolios are still in their infancy, which is probably why it would be tough to create a single Magic Quadrant combining UC and UCaaS. The UC Magic Quadrant has been around for a number of years and the vendors featured have come to rely on Gartner's annual feedback to know how they are performing or are perceived in the marketplace. But when we no longer need two Magic Quadrants for UC, then we can truly consider it unified.
See Gartner's Magic Quadrant for Unified Communications.
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