Cisco uses a proprietary cable pinout for their serial console cables.

Note: Pinout or pin-out is a term used in electronics to describe how an electrical cable is wired, or the function of each wire (pin) in a connector.

Given below are the pinout details for a Cisco cable.

9-pin Cisco Cable Cable Pinout

Signal DB9F RJ45
Receive Data 2 3
Transmit Data 3 6
Data Terminal Ready 4 7
Ground 5 4
Ground 5 5
Data Set Ready 6 2
Request to Send 7 8
Clear to Send 8 1

25-pin Cisco Cable Cable Pinout

Signal DB25F RJ45
Shield Ground 1  
Transmit Data 2 6
Receive Data 3 3
Request to Send 4 8
Clear to Send 5 1
Data Set Ready 6 2
Ground 7 4
Ground 7 5
Data Terminal Ready 20 7

This data was contributed by the team at The Hardware Book.