Simplified Signalling 7

19th June 2020

By Neil Downing, VP Products at TMT Analysis.

This week has seen TMT Analysis do something that when I would have thought was totally impossible when started my career.

When I first came into Telecoms in the mid-1990s, I was involved in putting voice communications onto new technologies like IP. One of the significant challenges that I remember well was getting this new stuff to inter-work with something that had already been around for more than a decade, namely Signalling System number 7 (also known as SS7/C7).

For those unfamiliar with SS7 it is the main signalling system used in the telephony network, providing the language for all telecoms operators World-Wide to speak to one another. Most of us never think about it, but it actually takes a lot of complexity to tell the person in London that the phone they are calling in Indonesia is actually engaged and play the right tones down the line to you. SS7 also contains a lot of inherent security to prevent rogue operators from inadvertently taking down the telephony network, something that governments have always feared.

Because it was complex, back then it was only for large operators, who could afford the people and systems needed to manage that complexity, so those from the new world created a range of other protocols for their needs, and only considered inter-working with SS7 as an absolute last resort.

However, in recent weeks I have been amazed by what I have seen. Whilst I was away from this area a couple of interesting things have happened. Firstly, the Internet standardisation bodies like the Internet Engineering Task Force (IETF) created a Signalling Transport (SIGTRAN) working group that worked with SS7 experts to come up with a viable inter-working standard between the Internet and SS7 worlds. Secondly, naturally flowing from this a community of software (and in some cases hardware) vendors have implemented gateway solutions that conform to these standards and ‘cross the divide’.

What does all this mean for someone like us at TMT Analysis?

It means that with a technically-gifted CTO and in particular a Director of Engineering (who just so happens is a subject matter expert on this) some commercially available software, a few virtual machines and a bit of time, our platform is now able to exchange SS7 signalling messages with other carriers, on a technically level playing field. This gives us access to a new level of richness in our number intelligence business and allows us to work with a much wider range of suppliers and partners.

It makes me very proud to see how the industry has worked together to break down and solve what was once a very complex problem and bring it into the realm of smaller, agile and innovative companies in the market, without compromising the experience for the millions of telephony users World-Wide that depend upon SS7, even if they don’t know it!

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