https://app.knowbase.one/vault/rfc/docid/1914
RFC8688: A Session Initiation Protocol (SIP) Response Code for Rejected Calls
Internet Engineering Task Force (IETF) E.W. Burger Request for Comments: 8688 Georgetown University Category: Standards Track B. Nagda ISSN: 2070-1721 Massachusetts Institute of Technology ...
https://app.knowbase.one/vault/rfc/docid/5541
RFC5079: Rejecting Anonymous Requests in the Session Initiation Protocol (SIP)
Network Working Group J. Rosenberg Request for Comments: 5079 Cisco Category: Standards Track December 2007 Rejecting Anonymous Requests in the Session Initiation Protocol (SIP) S...