Techniques are disclosed for conference expansion in a conferencing system. For example, a method of providing for conference expansion in a conferencing system includes the following steps. At least one port is reserved in an original conference allocated in the conferencing system. A hub conference is allocated, when a maximum number of participants for the original conference is reached. A calculated number of ports in the hub conference are reserved for linking to the original conference and to a corresponding number of expansion conferences when allocation of at least one of the number of expansion conferences is called for. The hub conference is linked to the original conference via the reserved port of the original conference and one of the reserved ports of the hub conference.