The manual (below) says 64 total callers on a conference. The 3CX site says 32 total callers. Which is it? Also, what license do I need to have 64 callers? Currently I have the 24 simultaneous calls license. Thanks. Call conferencing allows you to easily configure up to eight conference calls that can allow a total of 64 callers (license permitting). In other words the 64 caller limit is for all conferences, not per conference. Note that a conference with 64 participants will require a powerful machine. Although many conference call services exist, it’s often easier and cheaper to host your own audio conferences. Conferences can be set-up ad hoc, without the need to reserve a conference room. This has been done to simplify the set-up of conference calls. Note: The features are only available in the Standard and Pro editions of 3CX Phone System.