Troubleshooting T1/E1 & T3/E3 Links
XSR User’s Guide 4-9
2. Restart the controller:
XSR(config-controller<T1/0>)#no shutdown
If the T1/E1or T3/E3 controller and line are not up, check that either the T3/E3 NIM LOS or LOF
LEDs are shining or one of the following messages displays in the show controller output:
• Receiver has loss of frame (LOF), or
• Receiver has loss of signal (LOS)
Complete the following steps if the receiver has loss of frame:
1. Ensure the framing format set on the port matches the framing format of the line. If needed,
change the framing format configuration.
2. Change the Line Build-Out (LBO) using cablelength long/short (T1) or cablelength (T3)
commands. If needed, contact your service provider for more details on LBO configuration.
Complete the following steps if the receiver has a loss of signal:
1. Ensure the cable between the interface port and the T1/E1 or T3/E3 service provider
equipment is connected correctly.
2. Check the cable integrity by looking for breaks or other physical abnormalities in the cable.
3. Check the cable connectors.
T1/E1 & T3/E3 Alarm Analysis
Perform the following steps to troubleshoot for various alarms that can occur within the T1/E1 or
T3/E3 subsystem. The following troubleshooting flowchart displays the procedures.
Figure 4-4 T1/E1 & T3/E3 A larm Analysis Troubleshooting Flowchart (Part 1)

Receive Alarm Indication Signal (AIS - Blue Alarm)

1. Check that the framing format of the controller port matches the framing format of the line
provided by your service provider.
If your T1/E1 or T3/E3 controller still
does not function as desired,
contact your service/network provider
What kind of alarm is reported?
Alarm Analysis
Receive Remote Alarm
If a Transmit Remote Alarm
Indication (Yellow alarm)
If a Receive Alarm Indication
Signal (Blue alarm) is reported,
contact your service/network
If a Transmit Sending Remote Alarm
(Red alarm) is reported, check
your settings at the remote end
Transmit Alarm Signal
(Blue alarm)
Indication (Yellow alarm) is
reported, check your
settings at the remote site
provider
- refer to Figure 1-4 - refer to Figure 1-4