Which four of these key points should be considered during implementation of PPPoA architecture？（）

A. the number of subscribers that will be serviced currently and in the future because this affects the number of required PPPoA sessions
B. The types of applications that the NSP offers to the end subscriber
C. The capacity of ATM and Frame Relay interworking on the NSP
D. in the case of more than one user， whether all users need to reach the same final destination orservice，or they all have different service destinations
E. Whether the service provider or the final service destination is providing the IP address to the CPE of the subscriber