Convergence layer security in an NGN bearer network

Of the five measures, which measures can be taken to ensure convergence layer security in an NGN bearer network?

A.  Support ALCs based on IP addresses, ICMP, and UDP, including creating ALCs on virtual routers. Multiple filtering rules provide protection for the target network from multiple layers.

B. Bind IP addresses with MAC addresses and card numbers so that a user, including the port number and an MAC address under a port can be located accurately. In addition, provide corresponding measures to query malicious users.

C.  Limit the number of IP addresses to access the network from each user port. the number of PPP sessions, and the number of TCP/UDP connections.

D. BAS    vices must ensure that users are isolated from each other at the access side.

E. Check source addresses and control CAR of bandwidth available for users.