Wiring
Connectors
RJ45 Jack and Plug Pinout.
Cable connector's picture.
Ethernet Cabling
The TIA/EIA-568-A specifies two wiring standards for a 8-position modular connector such as RJ45. The two wiring standards, T568A and T568B vary only in the arrangement of the colored pairs. We are using T568B.
Straight-Through Cable Pinout (T568B):
RJ45 Pin # Wire Color 10Base-T Signal 1000Base-T Signal
(T568B) 100Base-TX Signal
1 White/Orange Transmit+ BI_DA+
2 Orange Transmit- BI_DA-
3 White/Green Receive+ BI_DB+
4 Blue Unused BI_DC+
5 White/Blue Unused BI_DC-
6 Green Receive- BI_DB-
7 White/Brown Unused BI_DD+
8 Brown Unused BI_DD-
Cross Over Cable Pinout (T568B):
RJ45 Pin # Wire Color RJ45 Pin # Wire Color (END 1) (END 2) 1 White/Orange 1 White/Green 2 Orange 2 Green 3 White/Green 3 White/Orange 4 Blue 4 White/Brown 5 White/Blue 5 Brown 6 Green 6 Orange 7 White/Brown 7 Blue 8 Brown 8 White/Blue
NOTE: The cross over cable layout is suitable for 1000Base-T operation, all 4 pairs are crossed.
The following diagram shows the Normal use of Crossed and Straight cables:
straight--HUB,SWITCH--crossed--HUB,SWITCH--straight--PC
PC--crossed--PC
NOTE': To avoid the need for Crossed cables many vendors provide UPLINK ports on Hubs or Switches - these are specially designed to allow the use of a STRAIGHT cable when connecting back-to-back Hubs or Switches. Read the manufacturers documentation carefully.
RS-232 Cabling
RS-232 Name/Function DB-25 DB-9 RJ-45 RJ-45 Signal (Input/Output) (Standard) (Standard) (Cyclades) (Netra/Cisco) Chassis Safety Ground 1 Shell Shell Shell Gnd Signal Ground 7 5 4 4 TxD Transmit Data (O) 2 3 3 3 RxD Receive Data (I) 3 2 6 6 DTR Data Terminal Ready (O) 20 4 2 2 DSR Data Set Ready (I) 6 6 8 7 DCD Data Carrier Detect (I) 8 1 7 - RTS Request To Send (O) 4 7 1 1 CTS Clear To Send (I) 5 8 5 8