Components and Protocols for Lync Web App Collaboration

This next section briefly describes the components a Lync Web App client interacts with during a collaboration session through the browser. As described in earlier sections, the Lync Web App Client facilitates all signaling through the Unified Communications Web API service running on the Lync Front End Services. However, the Web App Client will also communicate directly with conferencing components for media traffic. Figure 26.4 outlines the protocol flow for Lync Web App collaboration sessions.

Figure 26.4. Lync Web App protocol flow.

The following information is outlined in Figure 26.4:

• The Conferencing Services and Conferencing Focus are logical services located on Lync Front End Servers. The Conferencing Focus is responsible for coordinating conferencing resources and the conferencing join process for clients. The Conferencing Services would include the Audio/Video Conferencing Service, Application Sharing Conferencing Service, Data Conferencing Service, and IM Conferencing Service. The services have been combined in the diagram for simplicity.

• Lync Web App clients send all signaling traffic to the Front End Pool and through the UCWA service. If the user is external (see the bottom of the diagram), this traffic must be securely published through a reverse proxy solution.

• Lync Web App clients send media traffic through the appropriate conferencing service. If the user is external, the traffic is securely relayed through the Lync Edge Server.