Check the listing for details. Consultronics CoBRA HH - ISDN BRI / PRI Analyzer and Emulator. Condition: Used. Listed at 700.00 USD. #183Consultronics CoBRA HH - ISDN BRI / PRI Analyzer and Emulator. This unit is used and in good condition. or some years, ISDN has been the technology of choice for voice sessions and remote radio broadcasts. ISDN stands for Integrated Services Digital Network. It is a set of communication standards for transmission on the traditional copper lines of the Public Switched Telephone (PSTN)Network. It is capable of transmitting voice as well as data using a digital line. You can make phone calls, video calls, transmit data, and other network services over the circuits of the traditional phone lines.How does ISDN work?ISDN splits the traditional copper telephone line into multiple channels that operate concurrently on a single copper line.·A B channel, or Bearer channel, is used for voice and user data.·A D channel, or Delta channel, is a combination of data, packet networking, control, and signaling.B channel transmits the signal in a circuit-switch network, whereas the D channel transmits data with the help of packets. Each B channel has a capacity of 64 Kbps, and each D channel comes with a capacity of 16 Kbps. Combined, these channels help ISDN control the transmission of information.ISDN BRI And ISDN PRI are the two types of ISDN services. Both PRI and BRI ISDN use B channels for sending data and D channels for other forms of communication. The difference lies in the number of channels they use to accomplish this. What you see in the pictures is what you will receive.