A telecommunications system according to an embodiment of the present invention includes an instant messaging (IM) server and a VoIP server; and a plurality of system clients having both VoIP and IM sub-clients. The system clients can log on to their respective servers in parallel. The IM server and the VoIP server can communicate lists of common participants and allow for IM conferences among at least subsets of the system clients while an audio or video teleconference is ongoing.