Diameter Protocol Stack on the Gx Interface
Diameter is used for information exchanging on the Gx interface.
Diameter is an Authentication, Authorization, and Accounting (AAA) protocol developed by the Internet Engineering Task Force (IETF) for next-generation AAA servers. Diameter is defined in RFC 3588 and derived from the Remote Authentication Dial In User Service (RADIUS) protocol.
Diameter is mainly used in mobile communication systems, whereas RADIUS defined in RFC 2865 is used for fixed network access. However, as fixed and mobile networks converge, demands for unified AAA servers are becoming urgent and the Diameter protocol stack is required, therefore, to support fixed network access.
As shown in Figure 1, Diameter is used in the application layer of the protocol stack, and Transport Control Protocol (TCP) or Stream Control Transmission Protocol (SCTP) is used in the transport layer. The NetEngine 8000 F supports IP and does not support SCTP or IPsec.
When Diameter is used on the Gx interface, its extended application protocols are called Gx applications. Figure 2 shows the Gx interface protocol stack.
