Switch.co founder and CEO Craig Walker has been around the block a few times in the Internet voice business. He sold his first startup, Dialpad, which made one of the first Voice-over-IP (VoiP) services, to Yahoo in 2005. After leaving Yahoo, he launched a new service called Grand Central, which later contributed much of the brains of Google Voice after the search giant purchased it in 2007

Flash-forward to 2014. The cloud rules. Mobile rules. Google is gaining power in the enterprise. And Walker’s latest startup, Switch Communications, is launching a new service that capitalizes on all of these things.

That service, called “Switch,” is deeply integrated with Google Apps. Walker told me that while Microsoft can offer a full stack of communications and productivity tools, including voice (with its Lync product), Google has everything … but the voice part. It’s the one question Google’s enterprise salesforce can’t answer when going head-to-head with Microsoft to compete for enterprise business, Walker told VentureBeat.

“Google Apps has been leader in cloud-based apps for the enterprise, with Gmail and Docs and Apps,” Walker said. “There are tens of millions of businesses now using Google Docs, and Google says they’re signing up 5,000 new businesses a day.”

“We want to build a product for that user that can make their voice communication as good as their email communication.”

Switch.co is a cloud-based, business-grade phone system that works across all devices and platforms, including iOS, Android, Mac, PC, Linux, and even the old desktop phone. The system provides callers with a business phone number that rings all of their devices, with controls that let others reach them when and where they like.

Switch.co mobile or desktop app can manage features like call transfer, company directory, visual voicemail, and switching between devices. When someone is calling in, for example, a window pops up on your screen showing the caller’s basic data, recent emails you’ve sent or received from them, docs you’ve shared, upcoming calendar events involving that person, and even some social media information like recent tweets.

“Work, as we know it, is transforming. It’s not a place you go; it’s an activity you do,” Walker said. “People work anywhere and everywhere these days, so why use a phone system that’s tied to your desk?”

Switch.co is currently available for Google Apps users as a private beta. Pricing for companies of all sizes is $15 per month, per employee, including a free company number and unlimited domestic calls and texts.

I asked Walker what he’s going to say when Google eventually knocks on the door and says “OK, we’re ready to acquire you now.” He said the answer would probably be no, because Switch.co may one day sell its voice solution to enterprises using Microsoft for productivity and communications.

But, Walker added, one should never say never.

Switch Communications is funded by Andreessen Horowitz and Google Ventures.