I want to configure Frame-relay over isdn thru dialup. Can anyone guide me on this.

the scenario is as given below:

i have client at location A. location A is connected to location B on serial port using Lease line. Location B is connected to location C thru Lease line on serial port.Now location C is connected to location D over ATM backbone using Nortel passport 7480. The same client has location E which connects to location D with ISDN BRI at both ends. Location D dials into location E and establishes the connectivity. For the above scenario, i want to configure end to end FR. Location A is central location of client and location E is remote location of the client. location E wants to access location A over end to end FR network. We are able to configure end to end FR if the location D is connected to E thru Lease line on serial port but in this scenario the last mile connectivity is on ISDN BRI.

An early response will be highly appreciated.

Thanks in advance.

kanwal