Allowing external computing systems to access a data conference with low risk of eavesdropping. An external computing system accesses a virtual lobby before joining the data conference. The virtual lobby is an object that may include a list of computing systems admitted to the lobby. An external computing system joins the lobby when it is included in a waiting list associated with the lobby. Being joined to the lobby does not allow full access to the live data exchanges in the data conference, but does facilitate functions that are less sensitive such as notifying a conference organizer that the joined party in the lobby would like to join the data conference. Upon receiving notice that an external computing system has joined the lobby, the conference organizer then provides further authorization for the external computing system to enter the data conference using any number of in-band or out-of-band mechanisms.