Documents by O. Levin
2003, RFC3508: H.323 Uniform Resource Locator (URL) Scheme Registration
2005, RFC4245: High-Level Requirements for Tightly Coupled SIP Conferencing
2006, RFC4574: The Session Description Protocol (SDP) Label Attribute
2008, RFC5168: XML Schema for Media Control
2008, RFC5239: A Framework for Centralized Conferencing