Need to understand conditions where call setup will bounce to a second FXO port in a Route Group. We had a condition where the primary port in an FXO Route Group for 911 calls was selected, but then hung, never bouncing to the second port. Both ports show registered in MGCP, but the first POTS circuit was out of service (dead) ... the second circuit was working normally. In call tests the first port would illuminate on the ISR, and that's it, indefinite delay. It wouldn't select the second port unless the line was physically removed. NG for 911 purposes. The circuits have since been repaired, so we cannot reproduce. TAC won't troubleshoot without debugs. Thoughts appreciated.