By 1999, the first phase of VoIP miracle had been achieved. People could make international calls for a fraction of the cost they previously paid. Companies like Vocaltec and ITXC had made significant contributions in making that happen. The next big thing in VoIP was pushing packetization to the trunk level. But the vision varied in the industry.
Service providers at the time had two choices: either continue using public Internet to transport national long distance voice traffic, or somehow re-engineer their own networks to become compatible with the data-voice convergence trend. The first option was simply not good enough because there was not enough IP bandwidth to transport high volumes of voice traffic. VoIP technology also was not mature and scalable enough to handle high volume voice traffic. Service providers therefore began a long march toward a re-engineered PSTN.
And there were several players around who bet on this move. Among them were Transmedia, IP Cell, IP Verse, Oresis, Santera, Telica, Convergent Networks, Sonus Networks, Rapid 5 Networks, EmpowerTel, Salix, Cisco etc. The legacy vendors also offered enhancements to their existing TDM switches.
The high density gateway and softswitch technology that these companies developed for the purpose is really the cornerstone of the re-engineering of public networks that is taking place around the world. It represented a giant leap for VoIP: from international arbitrage application to a robust carrier grade switching system. Had such carrier grade systems not been engineered, VoIP would not have developed the way it has.
The company that contributed the most in this significant industry development in VoIP history is Sonus Networks. Sonus has been a leader in changing the public network. Along with the vendors mentioned above, Sonus also built carrier grade media gateway and softswitching technology. The reason it made a more defining contribution comes down to a few factors that I have identified:
(1) The telecom equipment heavyweights were focused more on preserving their TDM footprint. Nortel and Lucent offered migration solutions in form of enhancements to the existing switches. This was not a compelling offer for service providers at the time. (2) The competing startup vendors like Telica and Santera were effectively looking to build cheaper circuit switches and package them with the IP interface. (3) Other competing vendors (which included some startups as well) were focused on RAS type platforms that integrated dial-up traffic. Since the dial-up traffic was a declining application (due to proliferation of broadband), the platforms failed to get much traction. (4) Cisco, which would have given Sonus the toughest time decided to focus on enterprise VoIP.
Sonus stayed clear of the universal port gateway trend. The company built its solution as IP from ground up. It optimized its product around PSTN-to-IP type of voice flow. In the process, it played a bigger role in transformation of public networks than any other equipment vendor.
In absence of Sonus, I think there would have been a delay in the deployment of VoIP trunking. The RAS type platforms would never have prevailed. In absence of Sonus, the service providers would have continued with slow deployment of patch enhancements from legacy vendors. Either that, or (possibly more likely) they would have bought more TDM switches.