Network Cabling - Formula Sheet

Network Cabling - Standards and Specification Sheet

This reference sheet summarizes the technical specifications, standards, and pin configuration formulas used in network cabling systems.

Ethernet Naming Syntax Formula

[Speed]BASE-[Medium]

• Speed: Defines the maximum transmission rate in Mega bits per second (e.g., 10 Mbps or 100 Mbps).
• BASE: Represents baseband signaling, meaning only one signal is transmitted over the physical medium at a time.
• Medium: The physical carrier standard, where 'T' represents Twisted Pair and letters like 'F', 'B', 'S', or 'X' designate fiber optic media.

Wiring Standard Pinout Formulas

Crossover Cable Mapping Relationship

The crossover connection is formulated by linking the transmit pins on End A to the receive pins on End B, and vice versa:

• Pin 1 (Tx+) on End A is mapped to Pin 3 (Rx+) on End B.
• Pin 2 (Tx-) on End A is mapped to Pin 6 (Rx-) on End B.
• Pin 3 (Rx+) on End A is mapped to Pin 1 (Tx+) on End B.
• Pin 6 (Rx-) on End A is mapped to Pin 2 (Tx-) on End B.

Rollover Cable Mapping Formula

The rollover cable reverses the entire pinout order. For any pin number i on End A (where 1 is less than or equal to i, and i is less than or equal to 8):

Pin (End B) = 9 - i

• Pin 1 on End A connects to Pin 8 on End B.
• Pin 2 on End A connects to Pin 7 on End B.
• Pin 3 on End A connects to Pin 6 on End B.
• Pin 4 on End A connects to Pin 5 on End B.
• Pin 5 on End A connects to Pin 4 on End B.
• Pin 6 on End A connects to Pin 3 on End B.
• Pin 7 on End A connects to Pin 2 on End B.
• Pin 8 on End A connects to Pin 1 on End B.