RTC Client API’s and Windows Vista


We are getting questions from developers about the RTC Client APIs (http://msdn2.microsoft.com/en-us/library/ms775893.aspx) and Windows Vista. Developers can use the RTC APIs to create messaging clients or utilities that work with Live Communications Server. Windows XP included these APIs with the OS but Vista does not. However this does not mean developers are being left high and dry.


Developers can distribute the RTC 1.3 APIs to systems running Vista in the same way they do for XP and 2000 under the terms of the license agreement included in the RTC API SDK (http://www.microsoft.com/downloads/details.aspx?FamilyID=c3a7bd15-fd1c-4bf7-a505-3f8faf1e120a&DisplayLang=en). The IM, Presence, Voice and Video functionality of the RTC 1.3 APIs work on Vista RTM. While audio and video quality are acceptable the quality level does not match what users using Communicator 1.0 have experienced in the past. Application sharing and white boarding require Windows NetMeeting, which Vista has replaced with Windows Meeting Space so these features of the RTC 1.3 APIs will not function on Windows Vista. For more information about NetMeeting alternatives on Vista see http://www.microsoft.com/windows/netmeeting/ .


We are not doing any new development on these APIs and will not be optimizing audio and video for Vista. We will support these APIs on Vista, but we will be fixing critical issues only. At this time we do not know of any existing issues with the RTC 1.3 APIs that require a fix. In fact we have not issued any fixes for these APIs since their original shipment in December 2004 and are very pleased with their reliability.


For the best experience on Vista, including conferencing, rich presence and optimized audio and video,  developers should plan on migrating their applications to the new Unified Communications Client Platform which will be available as part of our Unified Communications 2007 offerings. We will have more information about these APIs in the coming months.


For those you of installing the RTC Client API and building applications for the first time there is an issue in the RTC SDK when running on Vista. The sample API install, RtcApiSetup.msi, does not work on Vista. In order to install the APIs on Vista, developers need to create a setup project (an MSI) that includes a merge module from the SDK and then install this project. This is the same procedure you need to follow for your applications that use RTC 1.3, since RtcApiSetup.msi is NOT distributable, so developers who have already build an application need only install their application to get the RTC 1.3 APIs on their systems.

- Kyle Marsh

Principal Program Manager



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