HP ProCurve 7000dl Series Basic Management And Configuration Manual page 292

Configuring Serial Interfaces for E1- and T1-Carrier Lines
Troubleshooting a Serial Connection
5-20
Figure 5-10 shows a serial interface that is down.
ser 2/1 is down, line protocol is DOWN
Encapsulation is not set
Transmit clock source is TCLK
DCD=up DSR=up
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame
0 abort, 0 discards, 0 overruns
0 packets output, 0 bytes, 0 underruns
s
Figure 5-10. Using the show interfaces serial Command to Troubleshoot the Serial
Interface
Some possible problems and solutions are listed below:
The router is not receiving a signal from the CSU/DSU.
• Verify that you have configured the correct serial-mode setting for
the cable that you are using. For example, if you are using an X.21
cable, verify that you have configured serial-mode X21 for the
interface.
• Check the connections to make sure that the cable is not loose.
• If you have an extra X.21, V.35, or EIA 530 cable, try using that cable
to connect the serial module to the CSU/DSU.
• Check the LEDs on the CSU/DSU and ensure that it is up. The CSU/
DSU may be turned off, or it may have experienced a hardware failure.
The serial module is misconfigured.
• Compare the list of settings that you received from your public carrier
with the settings configured on the serial module. To view both the
settings you have entered and the default settings for the interface,
enter the following command. (See Figure 5-11.)
ProCurve# show running-config interface serial <slot>/<port> verbose
• Correct any settings so that the configuration for the serial module
matches that used on CSU/DSU.
DTR=down RTS=down CTS=up