3Com 3C63311 Reference Guide - Page 182

170 CHAPTER 5: PATHBUILDER S330 DIAGNOSTICS AND PERFORMANCE STATISTICS Table 27 Alarms Common to Several Modules (continued) Alarm Loss of Signal(LOS) Network Card Loopback Network Line Loopback Out of Frame(OOF) Meaning Troubleshooting Steps Cannot detect a signal at a configured port. This alarm is applicable to DS3 UNI, E3 UNI, OC3/STM-1 UNI, DS1 IMA UNI, and E1 IMA UNI ports. Check the cable between the interface port and the service provider's equipment/terminal equipment. Check cable connections. Check transmit and receive pairs for proper connection. Check terminating equipment. Call your service provider. A loopback is configured on the port. Loopbacks are for troubleshooting only and should not be present under normal operating conditions. If you are not troubleshooting the port, turn off the loopback. A loopback is configured on the port. Loopbacks are for troubleshooting only and should not be present under normal operating conditions. If you are not troubleshooting the port, turn off the loopback. The configuration settings on the port are not correct for the line, or the port configuration is correct, but the line is experiencing errors that result in an alarm. Verify that the framing format configured on the port matches the framing format on the line. Check the port's statistics report for evidence of a bad line; bursts of LCVs could indicate a timing problem. If connected to local DS3/E3/OC3 equipment, check that equipment's output level to make sure it is not overdriving the input.