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Nt Nodes

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), and it reports 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. The Nt reference point is stateless, and it is specified in 3GPP TS 29.154.

Use the Nt Interface application on our simulated SCEF to test the capacity and performance of a PCRF. Use our PCRF Emulator with the Nt interface application to test your SCEF/CIoT Device Management Gateway. 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.

Read more about our MTC/CIoT test solution.


The Nt application implements the following 3GPP procedures:

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

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.

As with all dsTest products, the node configurations and test scenarios are easily defined and configured with XML files that are validated against a published XML Schema to avoid invalid definitions. With our dsClient GUI, you can create, run, and archive tests, capture, graph and archive operational measurements, capture real-time data flows, and manage your dsTest servers and testing scenarios with a standalone application that runs on your PC.

SCEF Testing (Server Emulation)

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

PCRF Testing (Client Simulation)

The Nt application simulates the 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.

Advanced Testing Features

SmartEvents — Alter application behavior or coordinate multiple interface applications with SmartEvents. Our programmable, subscriber-level state machine gives you the ability to define handlers for specified application events that can then cause an event in another application to be executed. You can also configure handlers to modify subscriber information during run-time, introduce timers, or randomize subscriber behavior based on configurable probabilities to name a few of the many options in one of dsTest’s most powerful features.

SmartMessageElement — Insert, delete, or replace elements in Diameter, RADIUS, MAP, LDAP, GTP, REST, or SOAP messages with our SmartMessageElement solution. Define proprietary signaling or corrupt elements to facilitate negative testing. Your SmartEvents configuration defines when your elements are activated.

Traffic Profile — Draw the shape of your test actions across time with Traffic Profile. You can define the rate for any action as a static rate or reference a Traffic Profile configuration, which also means that multiple Traffic Profiles can be running concurrently. Use Traffic Profile in conjunction with the randomizing features in SmartEvents to design a test that more truly simulates real-world network activity.

Diameter Dictionary — Define a set of message templates against which all messages will be validated with our Diameter Dictionary. Whether you’re load testing or testing functionality all messages are validated.

Operational Measurements

dsTest provides rich sets of measurements for the Nt interface:

  • Transaction and transport layer attempts, successes, and failures
  • Transaction duration, transactions-per-second, and round-trip delay
  • Message and byte counters
  • Errors encountered and error indications received in messages

See our Online Help for Nt measurements, Diameter measurements, and socket measurements.

You can read more about the reporting features offered with dsTest and dsClient here.

Supporting StandardsNt Protocol Stack