What is the console cable?
Hello guys!
Today, I would like to present a little about the console cable.
Objetive
The purpose of this article is to introduce the console cable.
What is the console cable for?
A console port allows connection to the equipment without using any network protocol, such as TCP/IP, and uses a different “pinout” than the network ports (interfaces).

Figure 1 - Console cable appearance

Figure 2 - Console Cable Structure
How to use console cable?
How to Connect:
Install your adapter cable driver.
Use the RJ45 connector of the console cable to connect to the Console port on the Huawei device.
Use the console cable's DB9 connector to plug into the adapter cable.
Use the USB connector on your adapter cable to connect to your notebook.
How to access switch through console port?
Use the RJ45 console port as the configuration port.
Connect the RJ45 connector of the console cable to the RJ45 console port of the NIP.
Connect the console cable's DB9 connector to the PC's COM port.

Use the mini USB console port as the configuration port.
Connect the mini USB connector of the USB cable to the mini USB console port of the NIP.
Connect the USB connector of the USB cable to the USB port on the PC.

What is a serial port for?
The serial port is considered one of the most basic external connections to a computer.

Figure 3 - Console Cable Structure and Appearance
These ports use different pins that enable full-duplex communication, in which information can travel in both directions at the same time.
| RJ45 | Direction | DB25 | DB9 | Signal |
| 1 | -> | 5 | 8 | CTS (Clear to Send) |
| 2 | -> | 6 | 6 | DSR (Data Set Ready) |
| 3 | -> | 3 | 2 | RXD (Receive Data) |
| 4 | — | 7 | 5 | GND |
| 5 | — | 8 | 1 | GND |
| 6 | <- | 2 | 3 | TXD (Transmit Data) |
| 7 | <- | 20 | 4 | DTR (Data Terminal Ready) |
| 8 | <- | 4 | 7 | RTS (Request to Send) |
Table 1 - Pin assignment on the console interface cable
Console Cable Types
When we buy a new Huawei switch or router, the console cable with RJ-45/DB-9 tip comes in the box, but this must be specified by the Huawei partner responsible for your order.
It is currently possible to specify the common cable or USB if your Huawei router or switch supports console via USB.
For the conventional console cable there are two models:
Cable with RJ-45 end for the Huawei switch or router and another DB-9 for the computer.
Cable with two RJ-45 ends and an RJ-45/DB-9 adapter for the computer.

Conventional console cables are also known as “Rollover” cables, as their pinout is from 1 to 8 at one end and the connection is reversed at the other, that is, from pins 8 to 1.
If your computer or laptop does not have a DB-9 serial port, you can still use a USB/Serial adapter and connect the Huawei router to this adapter, and the adapter will be connected to your computer's USB.

This is a very popular option these days, especially if the Huawei switch or router does not have a USB console option.
These adapters are easily found on the market at computer stores. See illustrative image below.
Software and Settings for Local Console Access
To access the command line or CLI (Command Line Interface) of the Huawei switch or router you must now have Terminal Emulation Software.
When you start studying the subject you will notice Windows HyperTerminal as the first option, many times even the configuration screens will be shown as a reference.
But there are other options like Putty, TeraTerm, SecureCRT and many others.
I personally use Putty for both local connection via console and remote connection via Telnet and SSH, as it is free software and very simple to operate.
The default configuration that you must enter in your terminal emulator is as follows to access the CLI via console:
9600 bps
8 data bits
1 stop bit
no parity
no flow control
See the image below for an example of Putty's configuration.

To make the connection after configuring Putty you must choose Serial and your COM port number.
On computers with Windows and the serial port will normally be COM1, however with USB/Serial adapters or USB drivers this port may vary in numbering.


