Phone: (469) 634-4200

dsTest supports both server emulation and client interface simulator capabilities for the 3GPP LTE Nt Diameter interface.   The Nt reference point is located between the Policy and Charging Rules Function (PCRF) and the Service Capability Exposure Function (SCEF). The Nt reference point is used for reporting the transfer policies from the PCRF to the SCEF.  The PCRF uses the information received from SCEF and other available information to determine one or more transfer policies for background data to the application service provider.

Use the Nt Interface application on our simulated SCEF to test the capacity and performance of a PCRF.  Use our PCRF simulator node with the Nt interface application to test your SCEF/CIoT Device Management Gateway.  Customize Nt messages using our SmartAVP feature.  If you are testing CIoT/NB-IoT, dsTest can surround a device management gateway with all the interfaces needed to verify the SCEF, MTC-IWF and SCS functions required of the Device Management Gateway.   The Nt reference point is specified in 3GPP TS 29.154.

Comprehensive sets of Operational Measurements for the Nt application, Diameter, and socket level are collected at user-specified intervals and stored in a SQLite database on the dsTest server.  Real-time measurements may be retrieved through our dsClient CLI interface or graphed via our dsClient GUI interface.


The Nt application implements the following 3GPP procedures:

  • Background Transfer Data Request/Answer (BTR/BTA) – command code 8388723

The Nt Diameter application application ID is 16777348, is stateless, and the vendor identifier is 10415 (3GPP).

A complete set of events that can be generated with the Nt interface can be found here, and our Diameter Dictionary can be used to design, test, validate and interpret the results of your testing.

SCEF Testing (Server Emulation)

Our PCRF server emulator supplies an appropriate response  when applicable, eliminating the need to dedicate a production server to lab activities.  The Nt application allows users to validate SCEF functionality, performance and capacity in a realistic network environment, replicating a deployment configuration.

PCRF Testing (Client Simulation)

The Nt application simulates a SCEF Nt interface to your PCRF to determine the functionality, processing capacity and performance of the PCRF.   Execute timed chains of test events with a run-time command or during an automated test using our SmartEvents feature to trigger SCEF-initiated procedures.

Multiple nodes can be instantiated on a single server, each with scalable subscriber loads and transaction rates. In this mode the Nt interfaces of up to 1000 independent client nodes may be simultaneously simulated.  The nodes are fully independent and their subscriber configurations may also be independent, overlap, or be duplicated.

Supporting StandardsNt Stack, Diameter, dsTest, Developing Solutions

General Reference Guides

Read more about dsTest.