HDH installs and programs Telephone systems from all the top manufacturers, Panasonic, Avya, Nortel and more. On the residential side we give homeowners the ease of use they are looking for. The ability to intercom every room in the house, to use cordless phones without interruption, door control and baby monitoring. Commercially, HDH installs larger PBX systems that will support up to 60 extensions. We also program Voicemail systems for automated attendant and other key features.