dIVI Translation refers to a dual stateless IPv4/IPv6 translation technique. dIVI is an extension of 1:1 stateless IPv4/IPv6 translation ( IVI Translation) with features of

IPv4 Internet Protocol version 4 (IPv4) is the first version of the Internet Protocol (IP) as a standalone specification. It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. ...

address sharing and dual translation. dIVI-PD is a further extension of dIVI to be well used in Wireline (Fiber, DSL, Cable) and Wireless (3G/4G) access environment, where the prefix delegation (/64 or shorter) is preferred. dIVI-PD is now standardized as MAP-T http://tools.ietf.org/html/draft-ietf-softwire-map-t in the IETF. dIVI Translation is intended to benefit the network operators (ISPs) to effectively share the public

addresses among a set of customers (since IANA has run out of public IPv4 addresses). In parallel, it leverages IPv6 in the network in a manner that makes IPv4-customer originated traffic looks like native IPv6 traffic in the network, resulting in simplified operations. More importantly, (unlike CGN44, DS-Lite, CGN64 etc.) dIVI/dIVI-PD does not require any Stateful NAT, DNS64 and ALG in the network, thereby benefiting the network operator to not deal with any NAT logging etc. dIVI maintains end-to-end address transparency and bidirectional-initiated communications.

How it works

Stateless NAT464 building blocks

*Address translation defined in RFC6052 IPv6 Addressing of IPv4/IPv6 Translators is a stateless mapping scheme, which embeds

IPv4 address Internet Protocol version 4 (IPv4) is the first version of the Internet Protocol (IP) as a standalone specification. It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks ...

in network specific IPv6 prefix and forms IPv4-converted and IPv4-translatable addresses. The IPv4-converted IPv6 addresses are the IPv6 addresses used to represent IPv4 nodes in an IPv6 network. The IPv4-translatable IPv6 addresses are the IPv6 addresses assigned to IPv6 nodes for use with stateless translation. *Suffix extension enables multiple IPv6 nodes sharing a single public IPv4 address, with each node managing a different range of ports. This is achieved by defining suffix of the address format RFC6052.draft-bcx-address-fmt-extension Extended IPv6 Addressing for Encoding Port Range (https://datatracker.ietf.org/doc/draft-bcx-address-fmt-extension/) *Header translation and ICMP translation defined in RFC6145 IP/ICMP Translation Algorithm are algorithms to perform header translation between

and

IPv6 Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communication protocol, communications protocol that provides an identification and location system for computers on networks and routes traffic ...

, as well as between

ICMP The Internet Control Message Protocol (ICMP) is a supporting protocol in the Internet protocol suite. It is used by network devices, including routers, to send error messages and operational information indicating success or failure when com ...

and

ICMPv6 Internet Control Message Protocol version 6 (ICMPv6) is the implementation of the Internet Control Message Protocol (ICMP) for Internet Protocol version 6 (IPv6). ICMPv6 is an integral part of IPv6 and performs error reporting and diagnostic fu ...

. *Dual stateless translation can restore original IPv4 address. The advantage of stateless NAT464 is that the DNS translation DNS64 and application layer gateway ALG are not needed.draft-xli-behave-divi dIVI: Dual-Stateless IPv4/IPv6 Translation (https://datatracker.ietf.org/doc/draft-xli-behave-divi/) *Prefix extension is only applied to dIVI-PD. It constructs different delegated prefixes for each CPE.draft-xli-behave-divi-pd dIVI-pd: Dual-Stateless IPv4/IPv6 Translation with Prefix Delegation (https://datatracker.ietf.org/doc/draft-xli-behave-divi-pd/)

Case study

*Considerations for Stateless Translation (IVI/dIVI) in Large SP Networkdraft-sunq-v6ops-ivi-sp Considerations for Stateless Translation (IVI/dIVI) in Large SP Network (https://datatracker.ietf.org/doc/draft-sunq-v6ops-ivi-sp/)

IETF

* Stateless Translation techniques have been gaining traction at the IETF as well as production networks. IVI is now an IETF informational RFC, where dIVI is being actively discussed. Many operators have recently submitted a motivation document to push the IETF to standardize Stateless 4v6 techniques such as dIVI.

Stateless 4via6 being advantageous

*Stateless 4Via6 Address Sharingdraft-dec-stateless-4v6 Stateless 4Via6 Address Sharing (https://datatracker.ietf.org/doc/draft-dec-stateless-4v6/) demystifies the upsides with any Stateless 4v6 techniques. * It is worth pointing out that dIVI/dIVI-PD, unlike CGN44, DS-Lite, CGN64 etc., does not require any Stateful NAT, DNS64 and ALG in the network, thereby benefiting the network operator to not deal with any NAT logging etc.

Relation to IVI Translation

*Due to the stateless nature, the dual stateless translation can easily become single stateless translation by removing the second translator, see IVI Translation.

References

External links

www.ivi2.org
{{IPv6 Routing software IPv6 transition technologies