%% You should probably cite rfc6157 instead of this I-D.
@techreport{ietf-sipping-v6-transition-07,
    number =    {draft-ietf-sipping-v6-transition-07},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-ietf-sipping-v6-transition/07/},
    author =    {Gonzalo Camarillo and Karim El Malki and Vijay K. Gurbani},
    title =     {{IPv6 Transition in the Session Initiation Protocol (SIP)}},
    pagetotal = 15,
    year =      2007,
    month =     aug,
    day =       17,
    abstract =  {This document describes how the IPv4 Session Initiation Protocol (SIP) user agents can communicate with IPv6 SIP user agents (and vice versa) at the signaling layer as well as exchange media once the session has been successfully set up. Both single- and dual-stack (i.e., IPv4-only and IPv4/IPv6) user agents are considered. {[}STANDARDS-TRACK{]}},
}