Overview
AudioCodes is a leading vendor of advanced communications software, products and productivity solutions for the digital workplace. Our products are deployed on-premises or delivered from the cloud. Providing software communications, cloud-based platforms, customer premise equipment and software applications, our solutions and products are geared to meet the growing needs of enterprises and service providers realigning their operations towards the transition to all-IP networks and hosted unified communications and collaboration business services. In addition, we offer a complete suite of professional and managed services that allow our partners and customers to choose a service packages (or complement their own offering) from a modular portfolio of professional services.
Our products are deployed globally in enterprise and service provider cloud networks. Our products include session border controllers, or SBC, life cycle management solutions, VoIP network routing solutions, media gateways, multi-service business routers, IP phones, value added applications and professional services. Our high-definition VoIP technologies and products provide enhanced intelligibility and a better end user experience in emerging voice communications services. We have tens of millions of SBC, media gateway and media server sessions deployed in over 100 countries across the globe. Our high availability platforms cover the spectrum of low, mid and high-density applications for service providers and large enterprises.
With over 25 years in the telecommunications market, we offer a broad range of solutions and services for both enterprise and service provider deployments. These solutions are built around our field-proven VoIP product range. Our VoIP technology contains voice quality enhancements and best-of-breed VoIP network elements and applications, and has a proven track record in product and network interoperability with the industry’s leading companies. With full support for industry standard protocols such as SIP, and proven interoperability with industry leading soft switches, private branch exchanges, or PBXs, IP-PBXs, unified communications and contact center platforms, we deliver innovative solutions for virtually any voice communications environment, offering reduced total cost of ownership, enhanced features, and superior voice quality.
We have invested significant development resources in complying with Microsoft’s requirements for the purpose of becoming a Microsoft recognized partner for their unified communication solutions for the enterprise market, which are known as Microsoft Skype for business and Microsoft Teams. We have adapted some of our gateway products, IP phones, session border controllers, survivable branch applications, value added applications and professional services to operate in the Microsoft Skype for business and Microsoft Teams environment. Our products to the Skype for Business and Microsoft Teams Unified Communications market are sold primarily to our channel partners that distribute and integrate the Skype for business solution to enterprises.
In November 2019, we and our former Israeli subsidiary, AudioCodes Development Ltd. (which was merged into our company effective January 1, 2020), entered into a royalty buyout agreement, or the Royalty Buyout Agreement with the IIA relating to certain grants they had received from the IIA. The contingent net royalty liability to the IIA at the time of the Royalty Buyout Agreement with respect to these grants was approximately $49 million, or in this section, the Debt, including interest to the date of the Royalty Buyout Agreement. As part of the Royalty Buyout Agreement, we agreed to pay approximately $32.2 million to the IIA (to settle the Debt in full) in three annual installments starting in 2019. The annual installments were linked to the NIS and bore interest. Pursuant to the Royalty Buyout Agreement, we eliminated all royalty obligations related to our future revenues with respect to these grants. In December 2021, December 2020, and November 2019, we paid three installments of approximately $12.2, $11.6 and $10.7 million, respectively, due under the Royalty Buyout Agreement.
We offer a comprehensive professional services program intended to provide responsive, preventive, and consultative support of our networking products. Our professional services support networking devices, applications and infrastructures, allowing large organizations and service providers to realize the potential of a high-performance multi-service network.
Our headquarters and research and development facilities are located in Israel with research and development extensions in the U.S. and China. We have other offices located in Europe, Asia, Latin America and Australia.
Historically, a substantial portion of our revenue has been derived from large purchases by a limited number of OEMs, NEPs, systems integrators and distributors. Westcon Group, our largest customer, accounted for approximately 15.44%, 13.03% and 13.50% of our revenues in the years ended December 31, 2021, 2020 and 2019, respectively. In addition, ScanSource Communications Group accounted for approximately 10.9%, 13.47% and 16.0%, of our revenues in the years ended December 31, 2021, 2020 and 2019, respectively. Our top five customers accounted for approximately 38.70%, 37.70% and 41.50% of our revenues in the years ended December 31, 2021, 2020 and 2019, respectively. If we lose a large customer and fail to add new customers to replace the associated