Many approaches and topologies -including multicast and media mixing -have been proposed for distributed Internet conferencing. While existing solutions can work well for large or pre-arranged conferences, they can be less appropriate for smaller, impromptu ones. We present an alternative, full mesh conferencing, which allows any number of parties to communicate in a conference without a central point of control. The protocol allows parties to join and leave the conference at any time, and ensures that all members of the conference are always informed of new members. The paper gives an overview of the protocol, analyzes it, describes a simulation environment for it, and discusses its applicability to the Session Initiation Protocol (SIP) and to other forms of decentralized communication.