%% You should probably cite draft-ietf-ipsecme-tcp-encaps instead of this I-D.
@techreport{pauly-ipsecme-tcp-encaps-04,
    number =    {draft-pauly-ipsecme-tcp-encaps-04},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-pauly-ipsecme-tcp-encaps/04/},
    author =    {Tommy Pauly and Samy Touati and Ravi Mantha},
    title =     {{TCP Encapsulation of IKEv2 and IPSec Packets}},
    pagetotal = 18,
    year =      2016,
    month =     apr,
    day =       25,
    abstract =  {This document describes a method to transport IKEv2 and IPSec packets over a TCP connection for traversing network middleboxes that may block IKEv2 negotiation over UDP. This method, referred to as TCP encapsulation, involves sending all packets for tunnel establishment as well as tunneled packets over a TCP connection. This method is intended to be used as a fallback option when IKE cannot be negotiated over UDP.},
}