Non-UI IP Phone Functionality (Windows CE 5.0)
Most of the functionality made available by TUI comes from discrete pieces of software provided with Windows CE. These pieces include the VoIP Application Interface Layer (VAIL), the RTC Client API, Exchange integration, and PC authentication. (Because RTC is used by the VAIL and the TUI, RTC is not discussed in this topic. See Real-time Communications.)
One of the most important pieces of IP phone functionality is the VAIL. Like the TUI, the VAIL is supplied in source code form so it can be modified. In addition, because of the modular architecture used by the Windows CE IP phone implementation, the VAIL can be replaced entirely.
You add the VAIL to a run-time image using the VoIP Application Interface Layer (VAIL) Catalog item, which is available in the Voice over IP Phone Services section of the Platform Builder Catalog. For more information about this Catalog item, see VoIP Application Interface Layer (VAIL).
VAIL provides two key benefits:
- VAIL abstracts the use of the SIP stack and media transport from the IP phone's UI. Among other things, this enables the UI to stay constant, for example, even if the SIP stack changes.
- VAIL provides a great deal of functionality common to most IP phones so that each device doesn't need to re-implement common requirements, which reduces the time it takes to develop an IP phone.
See Also
IP Phone Functionality in Windows CE | Customizing Non-UI IP Phone Functionality
Send Feedback on this topic to the authors