Conferencing Servers
Microsoft Office Communications Server 2007 and Microsoft Office Communications Server 2007 R2 will reach end of support on January 9, 2018. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.
A conferencing server is responsible for managing one or more media types. The following types of conferencing servers are included in Office Communications Server 2007:
Web Conferencing Server for data collaboration
A/V Conferencing Server for audio and video
IM Conferencing Server for multiparty IM
Telephony Conferencing Server for interfacing with audio conferencing providers (ACPs)
The architecture allows the addition of other conferencing servers as needed in the future. A/V Conferencing Servers and Web Conferencing Servers can be installed independently of other components. The IM Conferencing Server and Telephony Conferencing Server can be installed only as part of a Front End Server.
Web Conferencing Servers, A/V Conferencing Servers, and IM Conferencing Servers each have two logical components: a media controller and a media processor.
MC (Media Controller)
The media controller on a conferencing server is responsible for managing the control commands between a Focus and a conferencing server.
MP (Media Processor)
The media processor is responsible for media management such as mixing, relaying, and transcoding. In a Web Conferencing Server, the media processor is a software component that is responsible for managing data collaboration for Office Communications Server. In an A/V Conferencing Server, the media processor mixes audio streams, switches video streams, and converts the media for clients who are on slow links. Of all the conferencing components, the media processor can be the most CPU and network intensive component. In our architecture, a media controller and media processor are co-located on the same computer to simplify deployment.
A/V Conferencing Server
The A/V Conferencing Server enables multiparty audio and video mixing and relaying capabilities. It is built on industry standard Real Time Transport Protocol (RTP) and Real Time Transport Control Protocol (RTCP). The A/V Conferencing Server also uses proprietary RTP/RTCP extensions. Details of Office Communications Servers RTP/RTCP extensions are available under the terms of a licensing agreement.
The A/V Conferencing Server also incorporates elements of the IETF drafts for Interactive Connectivity Establishment (ICE) as a means to enable the exchange of media between two or more clients that are using Network Address Translators (NATs). ICE is an extension to Session Description Protocol (SDP) that enables media streams to traverse NATs by including in the SDP multiple IP address and port combinations for a particular transport protocol, known as candidate transport addresses that the client can use to communicate with other clients. In an Office Communications Server environment, a client uses Session Traversal Utilities for NAT (STUN) and Traversal Using Relay NAT (TURN) protocols to obtain its candidate transport addresses from the Office Communications Server A/V Conferencing Edge Server. During negotiation, clients on either end exchange SDPs and then test candidate addresses for peer-to-peer connectivity. After the connectivity checks, clients renegotiate by including only the candidate transport address that succeeded in the SDP for a SIP re-INVITE request and response.
Although the A/V Conferencing Server incorporates elements of ICE, the server is not compliant with the drafts. As a result, interoperability is not supported with third-party implementations of ICE, STUN, or TURN. For more information about IETF drafts for ICE, see https://ietfreport.isoc.org/all-ids/draft-ietf-mmusic-ice-18.txt.
Web Conferencing Server
The Web Conferencing Server adds data collaboration functionality to Office Communications Server. The Web Conferencing Server is built on the same Persistent Shared Object Model (PSOM) technology used by the Live Meeting service. Both signaling and media are sent to and from a Web Conferencing Server using the PSOM protocol. The Web Conferencing Server supports Live Meeting features, such as Microsoft Office PowerPoint presentations, document presentations, chat, voting, white boarding, and application sharing.
The Web Conferencing Server uses shared folders on a file system to store conference state and conference contents. Universal Naming Convention (UNC) paths are configured on the Web Conferencing Server to refer to the shared folders, which are created by an administrator during Office Communications Server deployment. These folders for conference metadata and conference content can be located on the same computer as the Web Conferencing Server or, preferably, on a dedicated computer.
For information about the way that a Web Conferencing Server works, see the Web Conferencing Server section later in this guide.
IM Conferencing Server
The IM Conferencing Server is installed automatically on the Front End Server. The IM Conferencing Server enables multiparty instant messaging. The IM Conferencing Server uses SIP for signaling and media.
Telephony Conferencing Server
The Telephony Conferencing Server is installed automatically on the Front End Server. The Telephony Conferencing Server enables Office Communications Server to communicate with audio conferencing providers (ACP).