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prpl Foundation HL-API Certification - What You Need to Know

Watch the prpl Foundation's webinar on HL-API certification here:

As many operators move towards open-source broadband gateway platforms, several industry organizations have formed to standardize and facilitate their development. The prpl Foundation is one of the most prominent of these projects, whose membership has funded the creation of the prplOS, LCM, and prplMesh solutions.

One of the main advantages of having an industry organization backing solutions like these is the availability of clear, standardized testing and certification for your products. The prpl Foundation launched the first of these certifications, the prpl High-Level (HL) API certification, in November of 2023.

Here’s what you need to know about running the prpl HL-API certification testing in CDRouter and how to obtain certification for your products.

What is the prpl HL-API

The prplWare architecture Source:

prplWare is the name given to the suite of open-source libraries and APIs that are produced by the prpl Foundation. Its main components are:

  • prplOS - the underlying gateway operating system based on OpenWRT.
  • prplMesh - an open-source implementation of the Wi-Fi Alliance EasyMesh standard.
  • LCM -  Life-Cycle Management (LCM) project creates the open-source tools to dynamically deploy and remotely manage downloaded applications and services for service providers.

The remote management interface into prplWare is the High-Level API, or HL-API. The HL-API is defined using the Broadband Forum’s TR-181 Device:2 Data Model, and operated using the Broadband Forum’s User Services Platform (USP). USP gives applications a direct interface to manipulate and read the broadband gateway that is running prplOS. The HL-API also enables downloadable applications and services from LCM to be made portable between RDK-B and prplOS deployments using USP 1.3 Broker and Service mechanism.

The prpl Foundation defines a profile that must be implemented by prplWare devices. This profile is what is validated during the certification process.

How prpl HL-API self-certification works

The prpl HL-API certification program is a self-testing program. That means that, rather than having a third-party entity perform the testing on your device, you can use an approved tool with approved test cases and test your device in your own environment.  Once you have a set of passing results, you can export the results and submit them to the prpl Foundation for certification.

QA Cafe’s CDRouter is the official test tool of the prpl HL-API certification. A CDRouter system with the prpl HL-API certification and USP test expansions is used to test your product and produce results that you can submit for certification. This testing is fully automated and can be re-run as many times as necessary to aid in debugging and troubleshooting.

What is tested in the prpl HL-API certification

The prpl Foundation has worked to develop a set of test cases specific to achieving prpl HL-API certification.This testing involves validating the device’s implementation of the TR-181 data model in accordance with the data model profiles defined for prplOS. Five major test scripts iterate over the product’s TR-181 implementation in the following ways:

prpl_hl-api.1.1 (Profile GetSupportedDM) - This test performs the USP GetSupportedDataModel operation on the device to ensure that all of the data model objects, parameters, commands, and events defined in the prplWare profile are present and supported.

prpl_hl-api.1.2 (Profile Parameters Write) - This test performs the USP GetSupportedDataModel operation on the device and checks to make sure that all parameters that are meant to be writable as defined in the prplWare profile are reported as writable parameters.

prpl_hl-api.1.3 (Get) - This test iterates over the device’s supported data model and verifies that the data defined by the prplWare profile can be retrieved and that their data types and validation criteria are met.

prpl_hl-api.1.4 (Set) - This test verifies that all of the writable parameters defined by the prplWare profile can be set to valid values and that the change is applied to the data model.

prpl_hl-api.1.5 (Add and Delete) - This test verifies that the writable objects defined by the prplWare profile can be added and deleted.

How to get certified after you have passing results

When used with certification programs, CDRouter results can be exported and signed to ensure their integrity. These results are then submitted to the prpl Foundation certification committee.

The full details of the certification requirements are outlined in the prpl Foundation Program Guide for Certification but the most basic requirements include:

  1. Applicants must be members of the prpl Foundation.
  2. Testing must be conducted on prplWare components only.  
  3. The device considered for certification must have passed all of the required test cases.
  4. The results cannot have been altered in any way. CDRouter can sign certification results to guarantee they are legitimate.
  5. The committee must review the results for validity.

Where to learn more

Are you considering certification? Reach out to us at QA Cafe to learn more about getting your device certified for the prpl HL-API, or if you have any questions about the test plan or testing process. You can also learn more about prpl Foundation and membership options at