Accelero™ Diameter Application Platform

Enabling Policy, Charging and Subscription in EPC, IMS, MMD Networks

The promise of converged networks with an all-IP interconnectivity comes closer with the IP Multimedia Subsystem (IMS) in the UMTS/WCDMA/HSPA 3G network, the Multimedia Domain (MMD) of the CDMA2000/EV-DO 3G network and more recently with the Evolved Packet Core (EPC) of the LTE 4G network. While RADIUS was the original the protocol of choice, the Diameter protocol has been adopted as the standard for all aspects of policy, charging and subscription management.

Diameter is based on RADIUS but has been enhanced to support failover, transmission security, reliable transport, agent support, server initiated messages, capability negotiation, peer discovery and configuration and is expandable with command codes (CC) and attribute-value pairs (AVP). The base Diameter protocols have been defined in the IETF and these have been extended using additional CCs and AVPs by the 3GPP and 3GPP2 to support interfaces between the IMS, MMD and EPC network elements.

Charging/Policy functions include the On-line Charging System (OCS), Off-line Charging System (OFCS), Policy and Charging Rules Function (PCRF) that use Ro, Rf, Rx, Gx, Gy, Gz S6a, S6b, s6d and S9 interfaces. Subscription management functions include the Home Subscriber Server (HSS), Subscriber Location Function (SLF) that use Sh, Dh, Cx, Dx, and AAA that uses Wa, Wd, Wx, Wm, Wg, SWa, Swd, SWx, SWm  interfaces.

Diametriq’s Diameter

A key element of Diametriq’s Diameter Solution Suite™ is the Accelero™ Diameter Application Platform. Diametriq offers a very high performance, scalable, reliable carrier-grade Diameter-based platform that can be used to build 3G and 4G core network elements. Accelero Diameter has been used by tier one mobile equipment vendors and deployed in tier one operator networks around the globe.

Accelero Diameter includes support for the most popular Diameter interfaces used by EPC, IMS and MMD. As an option, the platform can also include the Accelero suite of SS7 interfaces to enable interworking with legacy technologies.

Another option offers the Diameter Relay, Proxy and Redirect agents allowing the developer to build Diameter-based network elements and applications.

Object-Oriented API

The Diameter protocol and applications are specified with a set of commands (or messages). Each command contains a set of Attribute Value Pairs (AVP). The Accelero Diameter implementation provides a user-friendly API that provides classes for each command, AVPs and the complex types. Simple Set, Get and Print methods are provided to enable access to the AVPs.

This interface provides a type-safe programming approach. Cumbersome searching within a command to retrieve the elements and the onerous task of encoding tags, etc. is completely abstracted from the developer. This results in clean, easy-to-use code.

The API also provides a flexible mechanism to support known vendor-specific extensions in this uniform format. Any unknown extensions received during runtime can be passed to the application for inspection and action. The API presents a uniform signature for all interfaces. For example, an application can use Sh and Rf interfaces seamlessly.

Distributed Server Mode

The Distributed Server Mode Package is designed to provide a single point of Diameter access to a set of distributed clients. The clients may be implemented as multiple processes, multiple nodes or a combination of both. The application clients communicate with the Diameter front-end server via an IP socket-based interface.

The Accelero Diameter front-end server provides a highly available 1+1 active-standby redundancy mechanism that synchronizes session and state information to enable recovery in the event of a failure. The front-end server provides a health monitor process to enable switchovers.

Linkable Library Mode

For compact architectures based on a single process the linkable library mode provides a seamless approach whereby the process can harness the features of the Diameter implementation in a multi-threaded model. Accelero Diameter runs in its own thread of execution, providing support for all features of capabilities exchange, watchdog, peer and session control.

Accelero Diameter also provides a multi-threaded dispatch and receive mechanism for communicating with the application worker threads. The Accelero platform extends a complete process infrastructure environment that can accelerate new application development. Library mode also supports Active/Hot Standby redundant operation.

Benefits of the Diametriq Diameter Platform

• Well deployed by Tier 1 operators around the globe
• Comprehensive Diameter application development environment
• Designed for high performance, small footprint requirements
• Distributed and Library Modes
• Supports Diameter application interfaces to support IMS and LTE domains
• Both C++ and Java API support on Lintel servers
• Adheres to the latest RFC 6733
• High performance stack suited for PCRF,  OCS, HSS

 Sample Accelero™ Diameter Deployments

• Motorola Solutions  is using Accelero™ Diameter for the LTE Public Safety Network based on Rel11 3GPP standards.
• Amdocs/Bridgewater  Systems uses Accelero™ Diameter in its AAA Service Controller for multiple access networks, including WiMAX and CDMA.
• Cisco uses Accelero™ Diameter in the LTE version of its SCE Service Control Engine family for credit control.
• TeleCommunication Systems (TCS) uses Accelero™ Diameter in its RFC 4006 compliant Rf/Ro Credit Control Client application for their GMLC product line as a part of Release 8 LTE specific charging upgrade.
• XIUS-bcgi uses Accelero™ Diameter in its RFC 4006 compliant Credit Control application.