System architecture of Skype presence in SharePoint

Business end-users really appreciate the SharePoint capability that displays presence information of your colleagues, e.g. in a people results overview. They take this capability for granted, and request the same in other (web)applications, and even on other devices - mobile in particular. However, that is not that trivial to accomplish. The SharePoint presence capability current really shines in the combinations of Microsoft specific clients - IE browser, Outlook mailclient -, and the Skype client process on the local device. That local Skype client process functions actually as interface gateway to access Skype functionalities: retrieve presence information, start chatting.

Windows OS
Presence indication in SharePoint pages works via Microsoft proprietary combination: IE plug-in, that communicates via a proprietary protocol on Windows OS level against the local Skype client (process). The local Skype client on its turn connects to the central Lync / Skype server.

With this IE plug-in enabled, and local Skype client active + logged in; the presence information of colleagues can be retrieved and visualized in IE

Mobile OS
On Mobile OS, the system architecture is in essence the same: the local Skype Client operates as ‘gateway’/interface to the central Skype server. Element of the local Skype client deployment is an API via which custom applications can invoke Skype (client) functionaliteit: Skype for Business App SDK. Current this API includes capabilities to start a chat, start a video playing. There is yet no endpoint in the Skype client API to retrieve presence information.