Telephony Wiring Components and Connection Standards

Telephony Infrastructure Terminology

Signaling Concepts

Signaling: The set of signals that are sent and received to and from central to establish one call.

• Pulse Dialing: We transmit the same number of pulses that represents the digit marked.
• Tone Dialing: Sends a tone for each digit dialed. The tone frequency sent is the result of adding the frequency of the row with the frequency of the column.

Network Interface Devices

• BAT (Database Access Terminal): Database access from a phone or rosette terminal responsible for uniting the internal network with each telephone terminal.
• PAU (Point of Entry Unit): Its function is the union between the network that comes from outside the housing and the domestic network of the user.
• RJ-11 Contact: It has 2 contacts.

Telephony Connectors

Connectors Found in Telephony:

• 4P4C: Used to connect the headset with the phone's body.
• 6P2C: Used to connect the phone to the phone line through the rosette (RJ-11).
• 6P4C (RJ-14): Used to connect RBT 2 lines, a PBX to a telephone, and an ISDN line to a PBX.
• 6P6C: Used to connect RBT 3 lines to a switchboard and a telephone switchboard.
• 8P8C (RJ-48): Used to connect ISDN telephone lines to the wall and TR1 to a passive bus.

Housing and Termination Points

Record-making (Junction Boxes): Boxes where BATs or rosettes are housed.

Cabling Types

Cables:

• Flat Cable: For 2, 4, 6, and 8 conductors (threads). Very useful for patch cords. It is often used for installation within corrugated tubing.
• Round Cable: For 2, 4, 6, and 8 conductors. It is the most used, as its round shape fits best for pipelines.
• Ladder Line: It consists of 2 wires individually coated by an insulator.
• Ribbon Cable: From 25, 50, 75, and 100 conductors. Used for switchboards, intercoms, and ICT installations.

Rosettes (Wall Sockets)

Rosettes:

• Surface: Bolted onto the surface. The cables are connected by screws.
• Recessed: Boxes built into the wall. Cables are connected through screws. This type is more commonly used.
• Keystone: Used for modular facilities. The cables are connected by means of a cutting tool and insert.

User Internal Piping

User-Pipe Internal:

• Individual tubes, corrugated or smooth, with a diameter of 20mm (plastic or PVC).
• Canaletas (Trunking) of 3 compartments: (TF, TVC, and TV/FM). The width of each compartment is 1.3 times the diameter of the largest cable to be installed.

Installation Practices in Older Facilities:

• If using bare wire, staples are often placed every 25cm.
• Separate telephony wires by about 25cm from low-voltage transmission lines.
• If telephone gutters are used, no other cables should pass through the same channels.