Subject: What is the pinout for RJ45 cables?
Date: 09/13/97
Pinouts for RJ45 jacks (Serial and 10Base-T)
A 10Base-T cable is wired with a straight thru cable.
Often either T568A or T568B is used instead of 10Base-T wiring:
10Base-T Wiring Chart
| Pin | Color | Signal |
| 1 | White-Blue | TD+ |
| 2 | Blue | TD- |
| 3 | White-Orange | RD+ |
| 4 | - | - |
| 5 | - | - |
| 6 | Orange | RD- |
| 7 | - | - |
| 8 | - | - |
|
T568A Wiring Chart
| Pin | Color | Signal |
| 1 | White-Green | T3 |
| 2 | Green | R3 |
| 3 | White-Orange | T2 |
| 4 | Blue | R1 |
| 5 | White-Blue | T1 |
| 6 | Orange | R2 |
| 7 | White-Brown | T4 |
| 8 | Brown | R3 |
|
T568B Wiring Chart
| Pin | Color | Signal |
| 1 | White-Orange | T2 |
| 2 | Orange | R2 |
| 3 | White-Green | T3 |
| 4 | Blue | R1 |
| 5 | White-Blue | T1 |
| 6 | Green | R3 |
| 7 | White-Brown | T4 |
| 8 | Brown | R4 |
|
A 10Base-T Cross-over swaps TD and RD.
That is, swap pins 1 and 3 as well as pins 2 and 6, on one
end of the cable.
AT&T 258A wiring is comparable to T568B
Serial cables must be pin-swapped ( 1 - 8, 2 - 7, etc.)
The serial pinout is the same as used by SCCS, though
the documentation in the USENET Serial Board II Owner's Manual
has the pin numbering swapped from above. These are their tables,
modified for the above pin numbering.
The USOC 4-Pair wiring can be used (swapping one side)
USOC 4-Pair Wiring Chart
| Pin | Color | Signal |
| 1 | White-Brown | T4 |
| 2 | White-Green | T3 |
| 3 | White-Orange | T2 |
| 4 | Blue | R1 |
| 5 | White-Blue | T1 |
| 6 | Orange | R2 |
| 7 | Green | R3 |
| 8 | Brown | R4 |
Serial Pinout Applications
| Connector | Pinout | Connect to | Pretend to be |
| DB25-M | DCE | Modem | IBM PC 25-pin |
| DB25-M | DTE | Terminal | |
| DB25-F | DTE | IBM PC 25-pin | Modem |
| DE9-M | DCE | Mouse | IBM PC 9-pin |
| DE9-F | DTE | IBM PC 9-pin | |
Serial Pinout Details
| RJ45 Pin | Wire Color | | DTE | | DCE |
| Name | DE9 | DB25 | | Name | DB9 | DB25 |
| 1 | blue | | CTS | 8 | 5 | | RTS | 7 | 4 |
| 2 | orange | | DCD | 1 | 8 | | DTR | 4 | 20 |
| 3 | black | | TD | 3 | 2 | | RD | 2 | 3 |
| 4 | red | | Gnd | 5 | 7 | | Gnd | N/C | 1 |
| 5 | green | | Gnd | N/C | 1 | | Gnd | 5 | 7 |
| 6 | yellow | | RD | 2 | 3 | | TD | 3 | 2 |
| 7 | brown | | DTR | 4 | 20 | | DCD | 1 | 8 |
| 8 | white | | RTS | 7 | 4 | | CTS | 8 | 5 |
Make Equinox terminal server cables as straight through with
pins 5 and 6 swapped on the Equinox side.
On cisco routers, as well as SPARC Netras, RJ45 jacks are also used.
The wiring is slightly different than the one listed above. They
have RTS/CTS flipped as well as DTR and DCD (actually, they use DSR
instead of DCD). Below is a table that reflects these changes.
Serial Pinout Details - cisco
| RJ45 Pin | Wire Color | | DTE | | DCE |
| Name | DE9 | DB25 | | Name | DB9 | DB25 |
| 1 | blue | | RTS | 7 | 4 | | CTS | 8 | 5 |
| 7 | orange | | DTR | 4 | 20 | | DSR | 1 | 6 |
| 3 | black | | TD | 3 | 2 | | RD | 2 | 3 |
| 4 | red | | Gnd | 5 | 7 | | Gnd | 5 | 7 |
| 5 | green | | Gnd | 5 | 7 | | Gnd | 5 | 7 |
| 6 | yellow | | RD | 2 | 3 | | TD | 3 | 2 |
| 7 | brown | | DSR | 1 | 6 | | DTR | 4 | 20 |
| 8 | white | | CTS | 8 | 5 | | RTS | 7 | 4 |
BayTech RPC and DS series data switches and power controllers have
yet another pinout. Below is a table that reflects their pinout.
Serial Pinout Details - BayTech
| RJ45 Pin | Wire Color | | DTE | | DCE |
| Name | DE9 | DB25 | | Name | DB9 | DB25 |
| 1 | blue | | DTR | 4 | 20 | | CTS | 8 | 5 |
| 7 | orange | | N/C | - | - | | GND | 5 | 7 |
| 3 | black | | RTS | 7 | 4 | | DSR | 1 | 6 |
| 4 | red | | TX | 3 | 2 | | RD | 2 | 3 |
| 5 | green | | RD | 2 | 3 | | TD | 3 | 2 |
| 6 | yellow | | DSR | 1 | 6 | | RTS | 7 | 4 |
| 7 | brown | | GND | 5 | 7 | | N/C | - | - |
| 8 | white | | CTS | 8 | 5 | | DTR | 4 | 20 |
If you are using a 10baseT patch cable to connect two serial ports,
one end must be changed from DTE to DCE or DCE to DTE.
The wire colors given here are those used in the adapters offered
by South Coast Computing Services, Inc. Verify the color code of
any connector you use by comparing pin numbers and configuration
with the pin number map in figures 1 and 2.