Labels:text | map | font | diagram OCR: WAN CIRCUIT VIEW Central office FCC common carrier circuit - State-regulated tariffed circuit Ameritech (Indianapolis) State tariffed ISDN circuit Southern Bell (Atlanta/Roswell) Southwest Bell (Houston) Southern Bell (Miami) Figure 2. When broken down into circuits, the WAN model from Figure 1 proves to be a complex system linked to different providers and falling under the jurisdiction of different governing bodies.