Length: 12 hours (divided into three ½-day, four-hour, sessions)


Description: With the emergence of new technologies and services like mobile broadband, the need for Authentication, Authorization, and Accounting (AAA) functionality has never been greater. Diameter serves as a base protocol that allows peers to exchange a great variety of messages and can be extended in order to provide AAA services to new access technologies. It is the primary signaling protocol for AAA and mobility management in IMS; it finds extensive application for policy and charging in 4G Long Term Evolution (LTE); and is also an integral part of the NGN network. The Diameter base protocol is intended to provide an AAA framework for applications such as network access or IP mobility. It is also intended to work in both local and roaming situations. This course covers the architecture, message format, transport, error reporting, message flows, accounting and security services to be used by Diameter applications.

Course Outline

Diameter Base Protocol

  •  Authentication, Authorization & Accounting (AAA) overview
  • Introduction to Diameter
  • Diameter specification
  • Protocol stack overview
  • Diameter applications
  • Diameter architecture – clients, servers & agents
  • Stateful agents
  • Stateless agents
  • Relay agents
  • Proxy agents
  • Redirect agents
  • Translation agents
  • Realm-based routing
  • Connections & sessions
  • Initiating messages
  • Diameter requests& answers
  • Security framework – TLS
  • Protocol structure
  • IP structure
  • TCP structure
  • SCTP structure
  • Diameter structure
  • AVP structure
  • Command codes
  • Attribute Value Pair (AVP) codes
  • Diameter base protocol commands and answers
  • Uses & examples
  • AVPs
  • Mobile IPv4 application
  • Architecture& entities
  • Diameter messages
  • AVPs
  • Network Access Server (NASREQ) application
  • Messages and call flows
  • AVPs
  • Other applications
  • 3GPP, credit control SIP

Diameter in IMS

  •  Overview of IP Multimedia System (IMS) architecture
  • IMS entities
  • IMS reference points
  • Cx & Dx reference points
  • Diameter messages on the Cx and Dx interfaces
  • Sh reference point
  • Diameter messages on the Sh interface
  • Charging architecture
  • Offline charging
  • Online charging
  • Policy in the IMS
  • Policy Control Function (PCF)
  • Call flows using SIP and Diameter

Diameter in LTE/EPC

  •  LTE architecture
  • EPC architecture
  • The Home Subscriber Server (HSS)/AAA
  • Enhanced Packet Core (EPC) reference points
  • S6a & S6d interfaces
  • Diameter messages on the S6a and S6d interfaces
  • S13 & S13’ interfaces reference point
  • Diameter messages on the S13 & s13’ interfaces
  • Mobility management call flows
  • Charging
  • Offline charging
  • Online charging
  • Policy in the EPC
  • Policy Control Function (PCF)
  • hPCRF (home)
  • vPCRF (visited)
  • Rx interface& Diameter messages
  • Gx interface& Diameter messages
  • Charging in the EPC
  • Online Charging
  • Gy interface& Diameter messages
  • Offline charging
  • Gz interface & Diameter messages

SCTP Link Issues

  •  Stream Transmission Control Protocol (STCP)
  • Functions
  • SCTP packets
  • SCTP chunk types
  • Payload
  • Control
  • Establishing an association
  • Data transfer & flow control
  • Terminating an association
  • Examples of messages and message flows

Exercises are provided throughout the course, re-enforcing a practical understanding of the material. In addition, each student will receive a high-quality workbook and all of the necessary supplies.

What You Will Learn

This course will give the student a solid background in the architecture, message format, technical specifications and uses of the Diameter protocol.

Who Will Benefit From This Course

This course will be an invaluable tool for those individuals responsible for maintenance and surveillance of the LTE or IMS network.. This is especially true for personnel working in a control center environment such as the NOC, INAC, ESAC, etc. Others that would benefit include those involved with network engineering, surveillance and planning.

Course Prerequisites

Knowledge of data communications and TCP or SCTP / IP would be helpful, but not necessary.


All of our instructors have years of experience developing and teaching technical courses at Telcordia Technologies (Bellcore) Learning Services in Lisle, IL.  They are all SS7 certified and CompTIA CTT+ Certified Professionals.

* This course is provided through special agreement with Telecom Training Associates, Inc.