The IESG has approved the following document: - 'Lightweight 4over6: An Extension to the DS-Lite Architecture' (draft-ietf-softwire-lw4over6-13.txt) as Proposed Standard This document is the product of the Softwires Working Group. The IESG contact persons are Brian Haberman and Ted Lemon. A URL of this Internet Draft is: http://datatracker.ietf.org/doc/draft-ietf-softwire-lw4over6/ Technical Summary: DS-Lite [RFC 6333] describes an architecture for transporting IPv4 packets over an IPv6 network. This document specifies an extension to DS-Lite called Lightweight 4over6 which moves the Network Address and Port Translation (NAPT) function from the centralized DS-Lite tunnel concentrator to the tunnel client located in the Customer Premises Equipment (CPE). This removes the requirement for a Carrier Grade NAT function in the tunnel concentrator and reduces the amount of centralized state that must be held to a per-subscriber level. A companion document describes the DHCPv6 options necessary for provisioning of Lightweight 4over6. Working Group Summary: The working group had active discussion on the draft and the current text of the draft is representative of the consensus of the working group. This document and the MAP-E document are closely related and it led to a lot of friction in the working group. Lightweight 4over6 is a solution designed specifically for complete independence between IPv6 subnet prefix and IPv4 address with or without IPv4 address sharing. This is accomplished by maintaining state for each softwire (per-subscriber state) in the central lwAFTR and a hub-and-spoke forwarding architecture. MAP-E can also offer these capabilities or, alternatively, can provide a reduction of the amount of centralized state using rules to express IPv4/IPv6 address mappings. This introduces an algorithmic relationship between the IPv6 subnet and IPv4 address. This relationship also allows the option of direct, meshed connectivity between users. Document Quality: The document has received adequate review. The Document Shepherd has no concerns about the depth or breadth of these reviews. There are several interoperable implementations of the scheme and they have been demonstrated and tested during the IETF meetings. Personnel: Suresh Krishnan is the document shepherd. Ted Lemon is the responsible AD. RFC Editor Note: This document is one of a set of five softwire documents that should be published with sequential RFC numbers. The numbering should be in the following order: draft-ietf-softwire-lw4over6 draft-ietf-softwire-map draft-ietf-softwire-map-dhcp draft-ietf-softwire-map-t draft-ietf-softwire-4rd
