About us

Decades on the wire, from X.25 to SIP

GENVoice is the telephony arm of GEN, Global Enterprise Networks, a UK partnership that has run communications for businesses since 1989. We started with EDI over X.25 and leased circuits, ran one of the largest dial-up networks in the world, and became a VoIP provider on Asterisk in 2000.

The senior partners who founded GEN still run it, every day, and our own telephony runs on the same switches we build for customers.

Telecoms heritage

We have carried calls for a long time

Before the internet, we ran Electronic Data Interchange over X.25 and X.400 on point to point leased circuits, then some of the first commercial dial-up internet access in the UK. As dial-up grew we built on Hayes Century remote access platforms, each rack carrying an E1 with 30 channels, and grew to 80 of them with points of presence in ten countries: the largest Hayes Century operation in the world.

We were the first to offer bonded ISDN2 for 128k digital access, toll-free dial-in a year before it reached the rest of the UK, and early cellular data over BT Cellnet. In 1990 we built our first machine learning network, to predict when telephone calls would end, an idea that lives on in our predictive dialler.

In 2000 we became a VoIP provider on Asterisk, offering IAX2 and then SIP to replace branch exchanges, and in 2005 launched the first public encrypted voice service. More than twenty-five years on, voice is still encrypted between handset and switch on every system we provide.

The whole story is on GEN's history page.

Milestones in voice and data

1989The partnership formed, running EDI over X.25 and then X.400
1990Our first machine learning network, predicting when telephone calls would end
1997The first 128k digital internet service, over bonded ISDN2
1997Hayes Century remote access, growing to 80 racks in ten countries
1999The first mobile data interface, over BT Cellnet
2000The first VoIP provider on Asterisk, with IAX2 and then SIP
2005The first public encrypted voice service, encrypted IAX2 and RTP
2007The first mobile dial-up and fax, over BT, O2 and Cellnet
TodayAsterisk and FreePBX switches from a handful of extensions to more than 10,000 endpoints

How we work

A partnership, not a corporation

Run by its founders

GEN is a general partnership under the law of England and Wales, with three senior and two junior partners. The senior partners founded it in 1989 and are involved every day, in client relationships and running the infrastructure as well as strategy.

Confidential by default

We publish no client names, logos, testimonials or case studies. Your business is yours, not ours to promote, and displaying it would make you a target.

Our own UK data centres

Hosted switches run on our own hardware and network, in data centres fully green powered since 2020. Nothing is sublet to a third party platform and nothing leaves the country.

Engineers, not call handlers

Every case is taken by an in-house UK engineer, averaging over 15 years on Asterisk, through the HelpDesk at any hour.

No lock-in

We abolished fixed-price, multi-year support contracts in 2010. Support is bought in hours at published rates, with no minimum term or notice period.

Manufacturer partners

We are partners of Yealink and Fanvil, two manufacturers still investing in open SIP, and supply, provision and support their handsets.