Found in the feature matrix at https://supportforums.adtran.com/docs/DOC-1115
20 SIP trunks and 300 simultaneous B2BUA calls with full VQM and media anchoring.
SIP proxy not yet specified but likely much higher than the 3120 which does between 10 and 20 depending on VQM. The 3140 pretty much crushes the 3120 in terms of every other specification.
