1 Introduction to Diameter Signaling Router

Mobile data traffic is growing exponentially, fueled by the introduction of smart phones, laptop dongles, flat-rate plans, social networking, and applications like mobile video. Operators are looking at Internet protocol (IP) networks such as Long Term Evolution (LTE) and IP multimedia subsystem (IMS) to provide the bandwidth required to support high data traffic requirements and applications. The CSPs need cost-effective solutions to address the growing gap between traffic and revenue growth.

The 3GPP Evolved Packet core (EPC) and IP Multimedia Subsystem (IMS) network architectures have specified the use of Diameter over Stream Control Transmission Protocol (SCTP) or Transmission Control Protocol (TCP) for many network interfaces such as for policy, charging, authentication, and mobility management. Many of interfaces are illustrated in the figure below. 3GPP and ETSI defines the Diameter protocol, it is the foundation Authentication, Authorization, and Accounting (AAA) functions in the Next Generation Network (NGN).

Figure 1-1 Selected Diameter Interfaces in LTE and IMS