Console And Auxiliary Port Considerations - Cisco CISCO1841 - 1841 Integrated Services Router Hardware Installation Manual

Connecting to a Console Terminal or Modem
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This section describes how to connect a console terminal or PC to the console port and how to connect
a modem to the auxiliary port.
Table 4-3 System Management Connections
Port
Console
Auxiliary
For information about cable pinouts, see the
document.
To avoid electric shock, do not connect safety extra-low voltage (SELV) circuits to telephone-network
Warning
voltage (TNV) circuits. LAN ports contain SELV circuits, and WAN ports contain TNV circuits. Some
LAN and WAN ports both use RJ-45 connectors. Use caution when connecting cables. Statement 1021
Hazardous network voltages are present in WAN ports regardless of whether power to the unit is OFF
Warning
or ON. To avoid electric shock, use caution when working near WAN ports. When detaching cables,
detach the end away from the unit first. Statement 1026
Before opening the unit, disconnect the telephone-network cables to avoid contact with
Warning
telephone-network voltages. Statement 1041

Console and Auxiliary Port Considerations

The router includes an asynchronous serial console port and an auxiliary port. The console and auxiliary
ports provide access to the router either locally (using a console terminal connected to the console port)
or remotely (using a modem connected to the auxiliary port). This section provides important
information about cabling that you should consider before you connect the router to a console terminal
or a modem.
The main difference between the console port and the auxiliary port is that the auxiliary port supports
hardware flow control and the console port does not. Flow control paces the transmission of data
between a sending device and a receiving device. Flow control ensures that the receiving device can
absorb the data sent to it before the sending device sends more. When the buffers on the receiving device
are full, a message is sent to the sending device to suspend transmission until the data in the buffers has
been processed. Because the auxiliary port supports flow control, it is ideally suited for use with the
high-speed transmissions of a modem. Because console terminals send data at slower speeds than
modems, the console port is ideally suited for use with console terminals.
Cisco 1800 Series Integrated Services Routers (Fixed) Hardware Installation Guide
4-6
One console cable (RJ-45-to-DB-9, blue)
One DB-9-to-DB-25 adapter
Color Connected Device
Light blue PC or ASCII terminal communication port
(usually labeled COM)
Black Modem for remote access
Chapter 4
Table 4-3 summarizes the system management connections.
Cisco Modular Access Router Cable Specifications
Power, Cable, and Antenna Connection Procedures
Cable
RJ-45-to-DB-9 console cable
RJ-45-to-DB-9 console cable with a
DB-9-to-DB25 adapter
OL-6425-03