@techreport{beck-sipping-svc-charging-req-01,
    number =    {draft-beck-sipping-svc-charging-req-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-beck-sipping-svc-charging-req/01/},
    author =    {Wolfgang Beck},
    title =     {{SIP endpoint service charging requirements}},
    pagetotal = 14,
    year =      2002,
    month =     dec,
    day =       20,
    abstract =  {Today, a SIP user wanting to charge for a service needs to establish an agreement with all prospective callers. This administrative overhead can be avoided if caller and callee can prove the duration and existence of a call in case of a dispute. The draft describes requirements for protocols and SIP extension that can be used to implement such functionality.},
}