The Axxess used be able to do "OPX" over T1, essentially DID or extension service with dialtone, and each channel had an extension number that was considered like any other extension, it could be added to a hunt group, extension list, answering point, DID destination. The primary use was networking to non-Intertel equipment, but some vendors used this to simplify installation of equipment such as conferencing servers, as it appears this is the case the T-1 is being fed "extensions" to a conferencing server.
You will need to contact the conferencing server vendor to see about re-configuring it, if possible, to work with the 3300. Note that some of that equipment was kind of specific to the system it was connected to, so it might not be possible depending on how it using the service.