ISDN synchronization problem with Aastra BP 250

[Wachange]

Dear PABX Gurus,

I have three service providers connecting the services to the BP250 PABX. All the services are using the ISDN connection. The main problem is synchronization of ISDN Trunks because there are three connections.

1. PABX to PLMN
2. PABX to PSTN
3. PABX to Router

I am looking for help on the PABX programming and network configuration on service provider side to make these connection work without network roles (Slave and Master) conflict.

Please help.

Regards