A method and corresponding equipment for setting up a conference call via
a communication network that uses session initiation protocol (SIP)
signalling for call setup, the method including steps (E1a E2a E3a E4a)
of providing during the call setup signalling to a subscriber invited to
participate in the conference call an indication that the call is a
conference call and including in the call setup signalling a reference to
a group document indicating information about the conference call, such
as the other invited participants, or including the group document
itself.