Comcast is launching the next phase of its X1 platform in Boston by offering a cloud-based DVR service and the ability to watch live, in-home streaming on mobile devices via a new app.

The cloud-based DVR recordings are provisioned over Comcast’s managed IP network, and are another element of its IP-based Viper platform, the latter of which emerged from Comcast’s Xcalibur effort several years ago.

According to Comcast’s “X1 DVR with cloud technology” FAQ, up to 40 devices can be registered for in-home live TV or DVR streaming, with up five devices streaming simultaneously. Content-wise, Comcast said all of a subscriber’s linear channels were available on the new app, as well as the use of the X1 guide, on home-bound devices.

For now, the service is available in Boston, where X1 made its debut two years ago, to new Xfinity customers. Comcast said it would roll out the new features to additional markets later this year.

With X1 DVR, authenticated Comcast subscribers can “check-out” DVR recordings by downloading them directly to a mobile device to take on-the-go; and access the X1 interface and live stream practically their entire TV channel lineup to IP-connected devices.

“We want to provide customers with the best television experience on every device, when they want it and where they want it,” said Matt Strauss, senior vice president and general manager, video services, Comcast Cable. “The cloud-based infrastructure of the X1 platform allows us to deliver on that promise, and give customers a more personalized viewing experience. We look forward to providing these features to more customers this year.”

Like other video service providers, Comcast is focused on offering live streaming out of the home, but today’s announcement gives them the ability to download their video content to view on-the-go.

To deliver these new streaming and download features to Xfinity TV customers, Comcast has launched a new Xfinity TV app for iOS tablets and smartphones and a dedicated portal for viewing on computers. To live stream their TV lineup or download DVR recordings while on tablets or smartphones in the home, customers can download the Xfinity TV app from the App Store, open the app and sign-in with their Xfinity TV credentials.

Once signed-in, customers can start browsing their full channel lineup in the guide or scan available recordings for download in the Saved menu. On laptops and computers, customers can sign-in through the Xfinity TV site to access their X1 guide and DVR recordings.

Cloud DVR allows subscribers to store content from their DVRs in the cloud, or more accurately, in data centers. At the SCTE Cable-Tec Expo in October, both Arris and Cisco demonstrated their cloud DVR offerings, which were both integrated into their respective end-to-end home networking platforms.

Cable operators can cut costs, such as truck rolls, with cloud-based DVR storage. For subscribers it provides the ability to serve up video to multiple IP-connected devices.