https://app.knowbase.one/vault/rfc/docid/3451
RFC3087: Control of Service Context using SIP Request-URI
Network Working Group B. Campbell Request for Comments: 3087 R. Sparks Category: Informational dynamicsoft April 2001 ...
https://app.knowbase.one/vault/rfc/docid/4130
RFC3773: High-Level Requirements for Internet Voice Mail
Network Working Group E. Candell Request for Comments: 3773 Comverse Category: Informational June 2004 High-Level Requirements for Internet Voice Mail Status of th...