Chapter 5 Cable Information And Specifications For Cisco 1800 Series Routers (Modular); Console And Auxiliary Port Considerations; Console Port Connections - Cisco 1841 - 3G Bundle Router Hardware Installation Manual

Cable Information and Specifications for Cisco
1800 Series Routers (Modular)
This chapter gives cable information and specifications for the console port, auxiliary port, and network
ports on your Cisco 1800 series integrated services router (modular). It contains the following sections:
•
•
For cable connection procedures, see
(Modular)".

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 cabling
information to consider before connecting the router to a console terminal or modem.
The main difference between the console and auxiliary ports is that the auxiliary port supports flow
control, whereas 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. Console terminals send data at slower speeds than modems;
therefore, the console port is ideally suited for use with console terminals.

Console Port Connections

The router has an EIA/TIA-232 asynchronous serial console port (RJ-45). Depending on the cable and
the adapter used, this port will appear as a data terminal equipment (DTE) or data communications
equipment (DCE) device at the end of the cable.
For connection to a PC running terminal emulation software, your router is provided with an
RJ-45-to-DB-9 cable.
To connect the router to an ASCII terminal, use the RJ-45-to-DB-9 cable and a DB-9-to-DB-25 adapter
(provided).
OL-5876-03
Console and Auxiliary Port Considerations, page 5-1
Preparing to Connect to a Network, page 5-2
C H A P T E R
"Cable Connection Procedures for Cisco 1800 Series Routers
Cisco 1800 Series Routers (Modular) Hardware Installation Guide
5
5-1