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How TM Forum Open APIs are accelerating innovation & delivery at Cerillion


We all use APIs on a daily basis, without even realising; from signing into websites with a social media account to making payments online. Brian Coombs, Cerillion's Product Director, explains how TM Forum Open APIs are powering Cerillion products and continue to drive innovation.

We all use APIs on a daily basis, without even realising; from signing into websites with a social media account to making payments online. Brian Coombs, Cerillion's Product Director, explains how TM Forum Open APIs are powering Cerillion products and continue to drive innovation.

Open APIs are the publicly available interfaces with which software developers can gain programmatic access to other applications. Put simply, they are the “interpreter” between systems that want to share data and interact with one another.

With ongoing innovations to mobile and cloud technologies and the increasing portability of data across systems, open APIs are allowing Communications Services Providers (CSPs) to speed up integration, improve customer experience and monetise new services.

In this Q&A, Brian Coombs, our resident Product Director, explains how Cerillion has put the implementation of TM Forum Open APIs at the forefront of its product strategy:
Hi Brian, what’s the difference between open APIs and TM Forum Open APIs?
Open APIs are publicly accessible APIs that have been built using open programming standards. The TM Forum is the industry body for the telecommunications sector and, in collaboration with its members, has put together a set of standard APIs – TM Forum Open APIs – to cover the core functions of a service provider’s business, the idea being that if all systems integrate using a standard set of APIs and a common language, then it’ll be much simpler to integrate different systems together.
Are they just for telecom companies then?
No, not at all, as just about every company is a digital service provider these days their reach is broad. We’ve spoken to a major car manufacturer, for example, who wanted to use them to sell services and bill for them. The operations are very generic; they just happen to be things that the telecoms industry has been doing for years.
And why is Cerillion interested in them?
As a provider of BSS/OSS products we are always looking ahead to what our customers will be asking us to support in our product. It was clear a few years back that the TM Forum Open APIs were a good idea and very likely to get a good take up as the advantages to operators are obvious.

With that in mind, we took the decision in 2018 to sign up to the Open API Manifesto, committing to use the APIs in our products going forward.
Is it just a commitment or have you started implementing them yet?
The timing was quite good for us as we had just started to embark on a project to incorporate the best of our two product lines, Skyline and Enterprise BSS/OSS, into the latest version of our product suite. This necessitated the creation of new REST APIs, so it made perfect sense to take the TM Forum Open APIs as the base for this, and to date, we’ve implemented 16 of the Open APIs.
Sounds simple – was it?
There are two ways you could implement APIs like this, the fastest being to add a separate integration layer to the outside of your product – a ‘wrapper’ that’s independent of the core functionality and used only by external systems. This can get you up and running quickly, but in the longer term means you have different paths into the system and have to maintain all of them.

So instead, we have put the Open APIs at the heart of our system, developed as microservices. Our products call these Open APIs to carry out operations in exactly the same way as a third-party system would. This has the advantage of having a single point of entry, and being sure that they will always be up to date, but it is a much larger rewrite of the system.
Did you have any problems implementing them?
The biggest task has been the mapping between the Open API structure, based on the TM Forum’s Information Framework, and our own database schema, which is an implementation of that, but with the variety and breadth you’d expect from a system that has evolved over many years.

Getting our teams to understand and talk the language of the TM Forum has been a big part of that, so to help with this we have recently completed a company-wide training program from the TM Forum.
Are you done now or are there more Open APIs to be implemented?
There’s definitely more to come. The TM Forum has defined more than 50 Open APIs so far, although not all are directly relevant to us. So we are creating them as we need them to feed new parts of the product suite, as part of our continuous agile development process. This means those we’ve done are there and ready to be used immediately rather than sitting on a shelf waiting until they are all finished.

We have projects underway now that will integrate with those we’ve done, and we’ll continue over the next few product releases to increase the number and functionality available through the Open APIs.

And finally, what tips would you have for service providers or other vendors looking to use the TM Forum Open APIs?
It’s really important to have a solid understanding of the Information Framework so you can have sensible discussions about how the Open APIs fit into your architecture and map to your data model. It is much harder if you are trying to figure that out at the same time as doing the development. So, make sure you get the foundation right, and then you can start building out the Open APIs incrementally as and where you need them.

About the author

Adam Hughes


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