British Telecom (BT) has started a trial of Carrier Grade NAT (CGN) for their “Option 1 Total Broadband” customers.  Since the RIPE region has now fully exhausted their IPv4 free pool, these types of IP address sharing schemes just seem inevitable.  At this point it seems though IPv4 addressing needs continue to grow faster than the deployments of native IPv6.  Unfortunately, IPv6 is not backward compatible with IPv4 and IPv4 addresses will continue to be required for all Internet customers either natively or through some type of transition technology as long as the vast majority of the content they wish to reach remains IPv4 only.

BT Retail Tests IP Address Sharing