i got a call form a business with a vertical voip setup. no ksu, phones plug into router. i ran a new ext for her and everything went ok. i really dont know much about these voip sets. now she wants to have loud ringing. the only way i can think of is with a ata but i dont think they give much ringing voltage. or i could put a small amp on the shop phone speaker but its new and if i open it up that will void the warrentee. anyone have any other ideas. thanks dave