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Cisco 7401ASR Installation and Configuration Guide
OL-5419-01 B0
AppendixA Specifications
Console and Auxiliary Port Signals and Pinouts
To determine whether a UTP cable is a crossover cable or a straight-through cable, hold the two RJ-45
connectors next to each other so you can see the colored wires inside the ends.
Examine the sequence of colored wires to determine the type of cable, as follows:
•Straight-through—The colored wires are in the same sequence at both ends of the cable.
•Crossover—The first (far left) colored wire at one end of the cable is the third colored wire at the
other end of the cable.
Console and Auxiliary Port Signals and Pinouts
The Cisco 7401ASR router does not support Data Carrie r De te ct (D CD). Ta ble A- 9 lists the RJ-45
console port signals.
Table A -10 lists the RJ-45 auxiliary port signals.
TableA-9 Console Port Signals
Pin Signal Direction Description
1 CTS Out Clear To Send (tracks RTS)
2 DSR Out Data Set Ready (always on)
3 RXD Out Receive Data
4 GND —Si gnal Gr oun d
—— Not connected
6 TXD In Transmit Data
7 DTR In Data Terminal Ready
8 RTS In Ready To Send
TableA-10 Auxiliary Port Signals
Pin Signal Direction Description
1 RTS Out Ready To Send
2 DTR Out Data Terminal Ready
3 TXD Out Transmit Data
4RING
1
1. RING is not supported on Cisco-supplied adapters. To use this pin, you must create a customized
cable.
In Ring Indication
5GND —Signal Ground
6 RXD In Receive Data
72
2. Pin 7 can be used as a DCD input for connection to a modem. The RJ-45-to -DB-25F adapter maps
DCD to this pin when used with a straight-through cable.
DSR/DCD
(RLSD) In Data Set Ready / Data Carrier Detect
(Receive Line Signal Detect)
8 CTS In Clear To Send (tracks RTS)