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Joining a Conference

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.

After a client joins the conference and the conference is created, the client must establish a media session with a conferencing server responsible for that media type. For each conferencing server that is involved in a conference, the Focus assigns a virtual SIP URI that is routable to the Focus itself. The initial notification from the Focus to the client contains the URIs for all conferencing servers in the conference.

A client can join itself to the conference in one of the following two ways:

  • To join to an IM Conferencing Server or an A/V Conferencing Server (Conferencing Servers that communicate using SIP), a client issues a direct media INVITE to the conferencing server URI.

  • To join to a Web Conferencing Server (which does not use SIP), a client issues an addUser C3P dial-in command targeted at the conferencing server URI. (All C3P commands are carried inside a SIP INFO.)

A presenter client will typically invite another participant into a conference by first sending an appINVITE directly to the other participant. (An appINVITE is an INVITE between client endpoints in which the body of the request contains the Focus URI for the conference.)

If that participant client supports C3P, it will join itself to the conference using one of the preceding methods.

If the participant is a client with aversion of Office Communications Server prior to 2007, the presenter client will receive a 415 error that will cause the presenters client to issue an addUser C3P dial-out command to the conferencing server URI, to have the conferencing server directly connect to the legacy client.