%% You should probably cite rfc2881 instead of this I-D.
@techreport{ietf-nasreq-nasmodel-02,
    number =    {draft-ietf-nasreq-nasmodel-02},
    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-nasreq-nasmodel/02/},
    author =    {Mark A. Beadles and David Mitton},
    title =     {{Network Access Server Requirements Next Generation (NASREQNG) NAS Model}},
    pagetotal = 20,
    year =      2000,
    month =     may,
    day =       17,
    abstract =  {This document describes the terminology and gives a model of typical Network Access Server (NAS). This memo provides information for the Internet community.},
}