@techreport{despres-intarea-4rd-01,
    number =    {draft-despres-intarea-4rd-01},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-despres-intarea-4rd/01/},
    author =    {Rémi Després and Satoru Matsushima and Tetsuya Murakami and Ole Trøan},
    title =     {{IPv4 Residual Deployment across IPv6-Service networks (4rd) ISP-NAT's made optional}},
    pagetotal = 19,
    year =      2011,
    month =     mar,
    day =       14,
    abstract =  {This document specifies an automatic tunneling mechanism for providing IPv4 connectivity service to end users over a service provider's IPv6 network. During the long transition period from IPv4 to IPv6-only, a service provider's network will have to support IPv6, but will also have to maintain some IPv4 connectivity for a number of customers, for both outgoing and incoming connections, and for both exclusive and shared IPv4 addresses. The 4rd solution (IPv4 Residual Deployment) is designed as a lightweight solution for this. In some scenarios, 4rd can dispense ISPs from supporting any NAT in their networks. In some others it can be used in parallel with NAT- based solutions such as DS-lite and/or NAT64/DNS4.},
}