Forsix-2100A is Gigabit IPv6-IPv4 translator. Forsix-Series ™,IPv4/IPv6 translator supports spontaneous transition from IPv4 to IPv6. It supports translation and tunneling protocols. Forsix-2100A supports ALG (application level gateway) such as DNS,FTP,SIP(VoIP) for transparent communication between IPv4 and IPv6 Forsix-2100A is for Internet service providers or enterprise operation, with powerful performance and advanced features. Forsix-2100A supports duplex operation(Active/Stand-by Mode)for reliability. If you have specific ALG, we can provide those kinds of ALGs with cusomizing service. If you have any questions, please let us know. Thanks a lot.