Console And Auxiliary Port Considerations; Console Port Connections - Cisco Network Device 2800 Introduction Manual

Port and Cable Information for Cisco 2800 Series
Routers
This document provides information about cables needed to install your Cisco 2800 series integrated
services router. It includes the following sections:
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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 discusses 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 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. 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 appears as a DTE or 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 adapter 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 with the Cisco 2801 router only).
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Console and Auxiliary Port Considerations, page 1
Preparing to Connect to a Network, page 2