OpenWrt as AFTR issue

Hi,

Is it possible to build an AFTR router and B4 router in a test environment using OpenWrt ??

B4 and AFTR are just router names for the DS-Lite two main functions: Encapsulation, decapsulation & NAT44

Or is it just the B4 that is possible to implement and you just insert the AFTR IP address that resides somewhere in your ISP network ??