1. A cluster of terminals for carrying a cluster-based conference, the cluster comprising: a super member terminal equipped with a super user agent which includes: a cluster member list including identities of terminals that are members of the cluster; a conference identity that identifies the conference to which the super member terminal participates; a cluster neighbour list that identifies any other one or more other super member terminals of other clusters which also participate in the conference; cluster parameters associated with the cluster including a split value Sv indicative of a maximum number of terminals that may be part of the cluster, wherein when the split value Sv is reached during the conference, the cluster is split, and a merge value Mv indicative of a minimum number of terminals that may be part of the cluster, wherein when the merge value Mv is reached during the conference, the cluster is merged with another cluster; and one or more member terminals; wherein for carrying on the cluster-based conference, communications sessions are established i) between the super member terminal and each one of the one or more member terminals, and ii) between the super member and each any other one or more other super member terminals.