%% You should probably cite rfc7651 instead of this I-D.
@techreport{gundavelli-ipsecme-3gpp-ims-options-05,
    number =    {draft-gundavelli-ipsecme-3gpp-ims-options-05},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-gundavelli-ipsecme-3gpp-ims-options/05/},
    author =    {Aeneas Noble and Sri Gundavelli and Jouni Korhonen and Florin Baboescu and Brian Weis},
    title =     {{3GPP IP Multimedia Subsystems (IMS) Option for the Internet Key Exchange Protocol Version 2 (IKEv2)}},
    pagetotal = 10,
    year =      2015,
    month =     apr,
    day =       23,
    abstract =  {This document defines two new configuration attributes for the Internet Key Exchange Protocol version 2 (IKEv2). These attributes can be used for carrying the IPv4 address and IPv6 address of the Proxy-Call Session Control Function (P-CSCF). When an IPsec gateway delivers these attributes to an IPsec client, the IPsec client can obtain the IPv4 and/or IPv6 address of the P-CSCF server located in the 3GPP network.},
}