Netflix and YouTube have led the development of a simple protocol known as DIAL to allow second screen apps to talk to server applications on network-connected devices and displays. Consumer electronics companies including Samsung and Sony have contributed to the development. YouTube, Dailymotion, Hulu, Disney and the BBC are among those interested in developing applications. It offers a simple open alternative to Apple AirPlay or other solutions such as Miracast and could change the way apps work with network connected televisions.
DIAL, which stands for DIscovery And Launch, is a simple protocol that second screen apps can use to discover and launch apps on first screen devices.
For instance, it means that users can simply launch a compatible mobile app and tap the “Play on TV” button in the app to view the output on a network-connected television device or display on the same home network.
Unlike AirPlay, which is currently proprietary to Apple and not available for licence to third parties, DIAL is an open specification that can be freely implemented without royalties. It has the potential to become widely supported, providing a missing link between second screen apps and first screen displays.
The DIAL protocol has two components: DIAL Service Discovery and the DIAL REST Service.
DIAL Service Discovery enables a DIAL client device to discover DIAL servers on its local network segment and obtain access to the DIAL REST Service on those devices. It is based on SSDP, the Simple Service Discovery Protocol defined by UPnP.
The DIAL REST Service is based on HTTP and enables a DIAL client to query, launch and optionally stop applications on a DIAL Server device.
Beyond that, it is up to developers to establish further communication, based on their requirements.
It does not address things like mirroring a display on a television screen. That is more the province of another system known as Miracast, a peer-to-peer wireless screencast standard created by the Wi-Fi Alliance based on WiFiDirect.
In many respects, however, DIAL is more open and flexible than Apple AirPlay. It can launch compatible apps installed on network connected devices or displays, or redirect a user to an apps store. If supported by the target device it will also be able to launch web apps.
DIAL can be implemented on many devices and not limited to Apple iOS or Android ecosystems. Code for a sample client and server implementation are available for download.
The DIAL specification and mark are copyright Netflix. The specification is maintained by Netflix and YouTube with input from a variety of partners. First screen applications have been registered by the BBC, Hulu, Dailymotion and Disney, among others.
Samsung and Sony provided significant guidance to ensure that DIAL would be a compatible and effective solution for first screen devices and also meet their goals for second screen user experiences.
It is understood that some Samsung and Sony devices already support DIAL. Other manufacturers are also expected to offer support.
As a software protocol, it could potentially be supported through a software update for existing devices.
AirPlay works brilliantly within the Apple ecosystem, for instance with an Apple TV. That may suit Apple and its ultimate ambitions in this space, but DIAL offers an alternative for the rest of the market. If it receives widespread adoption it could significantly increase the usability and functionality of smart television devices and displays.