I have a BCM 400 at the main location with a PRI and 3 BCM 50s at 3 other locations. I need to have the 50s to dial out the PRI at the 400. All 4 BCMs are networked and have 4 diget dial accross the Network to each other, not sure how to get the 50s to pick the PRI for outdial purposes. Any suggestions Thanks in advance