I have two G3si PBXs connected by a tie line (T1). From site A, I can dial the TAC of the tie line, then dial feature access codes on the B side. However, I cannot dial the TAC from site B then dial feature access codes for Site A. From Site B, when I dial the TAC, then the three digit FAC, I get reorder tone after entering the third FAC digit. I checked the tie line trunk COR and it looks ok. Where would this be blocked?