https://app.knowbase.one/vault/rfc/docid/7811
RFC7195: Session Description Protocol (SDP) Extension for Setting Audio and Video Media Streams over Circuit-Switched Bearers in the Public Switched Telephone Network (PSTN)
Internet Engineering Task Force (IETF) M. Garcia-Martin Request for Comments: 7195 Ericsson Category: Standards Track S. Veikkolainen ISSN: 2070-1721 Nokia ...