RFC 3588 is a release of the Diameter base protocol that the Internet Engineering Task Force (IETF) issued in 2003. RFC 3588 set standards for the newly developed Diameter base protocol, which was intended to overcome the limitations of the former protocol RADIUS. The Diameter base protocol provides an authentication, authorization, and accounting (AAA) framework for applications such as network access and data mobility in both home and roaming mobile LTE networks.

The 3588 release of the Diameter base protocol was made obsolete with the release of RFC 6733 in October 2012. The term RFC means Request for Comments, reflecting the IETF’s recognition of the Internet’s dynamic nature. The IETF publishes RFC documents free of charge to support its mission of helping make the Internet work better.