Yes, it is a four-line with intercom. Claims to work with up to 16 stations (there are 16 one-touch buttons, default programmed to extensions 11 through 26). Whether it is mass marketed, I don't know.
{{I have one going with five extensions (one is OPX). Existing customer found it on the internet and I agreed to provide and install. It has been working with no complaints since last Fall.}}
This system operates properly on unaltered loop current (ca. 50mA), but exhibits crosstalk. Neither I nor the telco could see any evidence of shorts. With loop current attenuated to 25mA, crosstalk is eliminated, but system operation suffers, particularly: dropped calls on transfer (also reported by local user on hold from afar), and unintended barge-in. Privacy can be released, but has not been.
Does anyone know, or know where I can find, the standards for local telephone loop? I am in Washington state and our regulatory agency referred me to IEEE. I tried ANSI and ATIS. Any other suggestions?
