| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 3261 | SIP: Session Initiation ProtocolJ. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, E. Schooler | Proposed Standard | July 2002 |
| 3264 | An Offer/Answer Model with Session Description Protocol (SDP)J. Rosenberg, H. Schulzrinne | Proposed Standard | July 2002 |
| 3279 | Algorithms and Identifiers for the Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) ProfileL. Bassham, W. Polk, R. Housley | Proposed Standard | May 2002 |
| 3550 | RTP: A Transport Protocol for Real-Time ApplicationsH. Schulzrinne, S. Casner, R. Frederick, V. Jacobson | Internet Standard | July 2003 |
| 3711 | The Secure Real-time Transport Protocol (SRTP)M. Baugher, D. McGrew, M. Naslund, E. Carrara, K. Norrman | Proposed Standard | March 2004 |
| 3947 | Negotiation of NAT-Traversal in the IKET. Kivinen, B. Swander, A. Huttunen, V. Volpe | Proposed Standard | January 2005 |
| 3948 | UDP Encapsulation of IPsec ESP PacketsA. Huttunen, B. Swander, V. Volpe, L. DiBurro, M. Stenberg | Proposed Standard | January 2005 |
| 4028 | Session Timers in the Session Initiation Protocol (SIP)S. Donovan, J. Rosenberg | Proposed Standard | May 2005 |
| 4145 | TCP-Based Media Transport in the Session Description Protocol (SDP)D. Yon, G. Camarillo | Proposed Standard | September 2005 |
| 4301 | Security Architecture for the Internet ProtocolS. Kent, K. Seo | Proposed Standard | December 2005 |
| 4303 | IP Encapsulating Security Payload (ESP)S. Kent | Proposed Standard | December 2005 |
| 4474 | Enhancements for Authenticated Identity Management in the Session Initiation Protocol (SIP)J. Peterson, C. Jennings · obsoleted by RFC 8224 | Proposed Standard | August 2006 |
| 4566 | SDP: Session Description ProtocolM. Handley, V. Jacobson, C. Perkins · obsoleted by RFC 8866 | Proposed Standard | July 2006 |
| 4572 | Connection-Oriented Media Transport over the Transport Layer Security (TLS) Protocol in the Session Description Protocol (SDP)J. Lennox · obsoleted by RFC 8122 | Proposed Standard | July 2006 |
| 4916 | Connected Identity in the Session Initiation Protocol (SIP)J. Elwell | Proposed Standard | June 2007 |
| 5245 | Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal for Offer/Answer ProtocolsJ. Rosenberg · obsoleted by RFC 8445, RFC 8839 | Proposed Standard | April 2010 |
| 5246 | The Transport Layer Security (TLS) Protocol Version 1.2T. Dierks, E. Rescorla · obsoleted by RFC 8446, RFC 9846 | Proposed Standard | August 2008 |
| 5389 | Session Traversal Utilities for NAT (STUN)J. Rosenberg, R. Mahy, P. Matthews, D. Wing · obsoleted by RFC 8489 | Proposed Standard | October 2008 |
| 5741 | RFC Streams, Headers, and BoilerplatesL. Daigle, Ed., O. Kolkman, Ed., IAB · obsoleted by RFC 7841 | Informational | December 2009 |
| 5763 | Framework for Establishing a Secure Real-time Transport Protocol (SRTP) Security Context Using Datagram Transport Layer Security (DTLS)J. Fischl, H. Tschofenig, E. Rescorla | Proposed Standard | May 2010 |
| 5996 | Internet Key Exchange Protocol Version 2 (IKEv2)C. Kaufman, P. Hoffman, Y. Nir, P. Eronen · obsoleted by RFC 7296 | Proposed Standard | September 2010 |