I can not connect a PSTN Gateway WellGate 3804A. In the 3CX manual appears a D-Link or Micronet VOIP Gateway on page 42 and I saw that menues are the same as WellGate 3804A
Is is the same as the micronet interface? Unfortunately those devices are very old but they do work. Try making a call, even though the line does register. What happens? Can you post server status log?