RFC 6733

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.

Since 2005, F5 has designed Diameter signaling management solutions that go beyond the standards. When deploying the F5 Traffix Signaling Delivery Controller (SDC), service providers receive:

  • A Diameter Routing Agent (DRA) with an advanced routing management engine that combines the functions of Diameter relay, proxy, redirect, and translation agents for routing, aggregating, and load balancing all Diameter traffic
  • Enhanced routing and session-binding functionalities, in both redirect and proxy modes, in a multiple PCRF or OCS environment.
  • A routing engine that works natively with load balancing and transformation engines
  • Full insight into Diameter messages and the ability to apply rules by any AVP
  • A Diameter Edge Agent (DEA) that provides enhanced security, interoperability, and routing functions at the edge of the mobile operator network to manage Diameter and SS7/MAP signaling between visited, home, and roaming GRX/IPX providers in roaming cases
  • Interworking function gateway for instant service connectivity between telecom protocols (Diameter, RADIUS, LDAP, SQL, HTTP, GTP’, Web Services, JMS, CAMEL, MAP)

The SDC supports multiple deployment schemes in heterogeneous vendor and signaling environments, both at the core and edge of the signaling network, and supports more than 50 Diameter protocols. 

Connect with F5

F5 Labs

The latest in application threat intelligence.


The F5 community for discussion forums and expert articles.

F5 Newsroom

News, F5 blogs, and more.