https://app.knowbase.one/vault/rfc/docid/4633
RFC4240: Basic Network Media Services with SIP
Network Working Group E. Burger, Ed. Request for Comments: 4240 J. Van Dyke Category: Informational A. Spitzer Brooktrout Technology, Inc. ...
https://app.knowbase.one/vault/rfc/docid/5165
RFC5552: SIP Interface to VoiceXML Media Services
Network Working Group D. Burke Request for Comments: 5552 Google Category: Standards Track M. Scott Genesys ...