A proposal for distributed conferencing on SIP using conference servers

Session Initiation Protocol (SIP) is the de facto standard for Voice over IP implementations. Although this standard does not define conferencing directly, many drafts and papers suggest extensions and solutions to this essential service. In this paper, we first define the issues that are to be considered when building a conference service, and then we motivate our work on some of the limitations of the existing suggested solutions. This framework facilitates the conference control and media handling of a VoIP conference and aims to create a scalable and distributed conferencing system both in terms of load and control. The conference control as well as media is distributed over the network using SIP Servers and Conference Servers, which are described. The floor control is made dynamic by using a metric called Loudness Number [10] that provides a feel of a physical face-to-face conference.