One other option is a Data Tracker (can be ordered via Avaya - probably other similar options out there from other suppliers) which has a built in Modem on one side, and connects to the same port as the SAT (SAT can in turn be plugged into the Tracker), this has a general password that needs to be entered prior to accessing the normal login prompt from the Definity.
This also allows upto 4 Devices to be accessed using one Dialup number (eg if you have them CMS, Conversant, MAP-D, ....)
Many programs can be used to dial up including PROCOMM or CV Terminal that is bundled with CV Supervisor, ...