About ESI - Legal


About Us

ESI-Legal, a part of Estech Systems, Inc. (ESI), delivers high-performance cloud phone systems that are easy to use and uniquely integrated, specializing in legal services and law firms. ESI provides end-to-end solutions that give businesses the power to choose the features that they need to meet their goals. ESI is a privately-held corporation headquartered in Plano, Texas.

What We Do

Founded in 1987, the company has sold over 350,000 phone systems and deployed more than three million phones nationwide.
ESI was the first company to build a truly combined telephone and voice mail system, as well as the first to build a purely IP-based business communications system, and has numerous patents granted or pending on its products' unique designs and capabilities. ESI is highly regarded for supporting uniquely integrated, real-world applications with practical and effective features.



ESI has numerous U.S. Patents either granted or pending on its product design. ESI's innovative products use significantly less hardware, resulting in increased reliability. Due to these and other advantages, ESI products provide significant benefits and greater long-term customer satisfaction. Patents that have been granted to ESI include:

6,067,349 and 7,221,741 - Dialing using Caller ID.

6,252,944 - Telephone call/voice processing system.

6,842,505 - Communications system enhanced with human presence-seeking capabilities.

6,925,167 - Service observing in a voice over IP telephone system.

6,940,962 - Dial-on-hold.

7,068,684 - Quality of service in a voice over IP telephone system.

7,123,699 - Voice mail in a voice over IP telephone system.

7,564,834 - Shared knowledge in a telephone system.


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