| 2827 | Network Ingress Filtering: Defeating Denial of Service Attacks which employ IP Source Address SpoofingP. Ferguson, D. Senie | Best Current Practice | May 2000 |
| 3261 | SIP: Session Initiation ProtocolJ. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, E. Schooler | Proposed Standard | July 2002 |
| 3323 | A Privacy Mechanism for the Session Initiation Protocol (SIP)J. Peterson | Proposed Standard | December 2002 |
| 3324 | Short Term Requirements for Network Asserted IdentityM. Watson | Informational | December 2002 |
| 3325 | Private Extensions to the Session Initiation Protocol (SIP) for Asserted Identity within Trusted NetworksC. Jennings, J. Peterson, M. Watson | Informational | December 2002 |
| 3711 | The Secure Real-time Transport Protocol (SRTP)M. Baugher, D. McGrew, M. Naslund, E. Carrara, K. Norrman | Proposed Standard | March 2004 |
| 3893 | Session Initiation Protocol (SIP) Authenticated Identity Body (AIB) FormatJ. Peterson | Proposed Standard | September 2004 |
| 4033 | DNS Security Introduction and RequirementsR. Arends, R. Austein, M. Larson, D. Massey, S. Rose | Proposed Standard | March 2005 |
| 4034 | Resource Records for the DNS Security ExtensionsR. Arends, R. Austein, M. Larson, D. Massey, S. Rose | Proposed Standard | March 2005 |
| 4035 | Protocol Modifications for the DNS Security ExtensionsR. Arends, R. Austein, M. Larson, D. Massey, S. Rose | Proposed Standard | March 2005 |
| 4301 | Security Architecture for the Internet ProtocolS. Kent, K. Seo | Proposed Standard | December 2005 |
| 4347 | Datagram Transport Layer SecurityE. Rescorla, N. Modadugu · obsoleted by RFC 6347 | Historic | April 2006 |
| 4474 | Enhancements for Authenticated Identity Management in the Session Initiation Protocol (SIP)J. Peterson, C. Jennings · obsoleted by RFC 8224 | Proposed Standard | August 2006 |
| 4475 | Session Initiation Protocol (SIP) Torture Test MessagesR. Sparks, Ed., A. Hawrylyshen, A. Johnston, J. Rosenberg, H. Schulzrinne | Informational | May 2006 |
| 4568 | Session Description Protocol (SDP) Security Descriptions for Media StreamsF. Andreasen, M. Baugher, D. Wing | Proposed Standard | July 2006 |
| 4732 | Internet Denial-of-Service ConsiderationsM. Handley, Ed., E. Rescorla, Ed., IAB | Informational | December 2006 |
| 5246 | The Transport Layer Security (TLS) Protocol Version 1.2T. Dierks, E. Rescorla · obsoleted by RFC 8446, RFC 9846 | Proposed Standard | August 2008 |
| 5351 | An Overview of Reliable Server Pooling ProtocolsP. Lei, L. Ong, M. Tuexen, T. Dreibholz | Informational | September 2008 |
| 5352 | Aggregate Server Access Protocol (ASAP)R. Stewart, Q. Xie, M. Stillman, M. Tuexen | Experimental | September 2008 |
| 5353 | Endpoint Handlespace Redundancy Protocol (ENRP)Q. Xie, R. Stewart, M. Stillman, M. Tuexen, A. Silverton | Experimental | September 2008 |
| 5486 | Session Peering for Multimedia Interconnect (SPEERMINT) TerminologyD. Malas, Ed., D. Meyer, Ed. | Informational | March 2009 |
| 5741 | RFC Streams, Headers, and BoilerplatesL. Daigle, Ed., O. Kolkman, Ed., IAB · obsoleted by RFC 7841 | Informational | December 2009 |
| 5853 | Requirements from Session Initiation Protocol (SIP) Session Border Control (SBC) DeploymentsJ. Hautakorpi, Ed., G. Camarillo, R. Penfield, A. Hawrylyshen, M. Bhatia | Informational | April 2010 |
| 6271 | Requirements for SIP-Based Session PeeringJ-F. Mule | Informational | June 2011 |
| 6406 | Session PEERing for Multimedia INTerconnect (SPEERMINT) ArchitectureD. Malas, Ed., J. Livingood, Ed. | Informational | November 2011 |