RFC 6733 (formerly known as 3588 bis) documents the latest Diameter protocol specifications and was released at the end of 2012 by the Internet Engineering Task Force (IETF). The release of this new standard makes the previous RFC 3588 (Diameter base protocol) and 5719 obsolete. Diameter is the base protocol for authentication, authorization, and accounting (AAA), enabling network access and IP mobility in both home and roaming mobile LTE networks.

This latest version of the Diameter base protocol defined in RFC 6733 is a positive step in developing Diameter signaling protocol, the central nervous system for LTE and next-generation networks. The upgrades were based on specific needs and requirements of telco operators.

Some of the improvements in this new version include:

  • Tighter security with better connections between peers by requiring the use of TLS/TCP and DTLS/SCTP
  • Added routing functionality and flexibility using routing tables add-ons
  • Additional SCTP functionality (Stream Control Transmission Protocol, a transport layer protocol)
  • Updates to AVPs and messages to enable additional functionality and better interworking
  • Caching mechanism to reduce signaling, increase performance, and enable additional routing capabilities

There will be other releases, as the standardization process is not yet complete.