Understanding ISDN: Key Components and Functionality

ISDN: A digital network from start to finish, which allows integration of multiple services into a single access.
Network Terminal: It is a device that converts the 2 wires that come in 4 needed to communicate.
Access Basic: Contains 2 B channels (64 kbps data rate) and D (signaling speed 16 kbps).
Primary Access: 2048 kbps speeds. The entrance to the building is through radio links, fiber optic... Sometimes the B channel is called H.
Terminal Adapter (TA): Devices to work with old equipment (faxes) in an ISDN installation.
Doorman: In the installation of 1 keeper, 4 wires are needed to connect the housing with the street, or 3 if we combine the negative. To select the call, the plant must send a signal, for example, by the common negative. If we want to open the door from the housing, we need another wire.
Elements:

• Entrance: As homes vary in size, buttons are used to make calls, and an amplifier allows us to communicate acoustically.
• Amplifier: Audio system operation. Adjusts the sound volume in both the home and on the street.
• Buttons: The board on the street has a button for each home. Its function is to send the signal to the corresponding housing intercom.
• Intercom: They have several buttons to call for counseling and special functions.
• Power Supply: Responsible for converting the voltage needed by the system.
• Mechanisms Openers: Open the front door automatically.

Videoporters:

• Telecamera: Allows you to focus on the person you are calling.
• Monitors: Lets you see the person you are calling.
• Feeder Video: Provides 18V DC to power the two above.
• Generator: Responsible for generating signals and checking the polarity of the line.
• Inductive Receiver: Receives signals from the generator and generates an audible tone.
• Check the Polarity of the Line: The generator does not send signals. If LINE1 is ignited, it is correct; if LINE2 is ignited, it is incorrect.
• Check the Continuity of the Cables: If there is continuity, LINE1 lights up; if there is no continuity, it does not light up.
• Tracking a Cable Laying: The generator injects an audible frequency in the cable, and the receiver detects a magnetic field, electric field, and makes it through an amplifier, producing sound from a loudspeaker.

Breakdown:

• It Does Not Work: 1) Pair open circuit, 2) Pair shorted, 3) Pair derived ground, 4) Two pairs bartered.
• Work: 1) Pair polarity backwards.
• Irrigation Supply: 1) Presence of strangers in the pair potential.
• You Hear Other Conversations in Our Line: 1) Even with bad insulation.
• Noise: 1) Noise on the line.