Troubleshooting guide

10-45
ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-01
Chapter 10 Troubleshooting Ethernet, ATM Uplink, and POS Uplink Interfaces
Troubleshooting Packet-over-SONET Uplink with Enhanced Gigabit Ethernet Interface Modules
Step 2 Check LOF (loss of frame)—LOF is detected when a severe error framing (SEF) defect on the incoming
SONET signal persists for 3 ms.
Step 3 Check LOS (loss of signal)—LOS is detected when an all-zeros pattern on the incoming SONET signal
lasts 19 plus or minus 3 ms or longer. This defect might also be reported if the received signal level drops
below the specified threshold.
Step 4 Check whether a Bit interleaved parity (BIP [B1]/BIP [B2]/BIP [B3]) error has been reported.
• For B1, the bit interleaved parity error report is calculated by comparing the BIP-8 code with the
BIP-8 code extracted from the B1 byte of the following frame. Differences indicate that section level
bit errors have occurred.
• For B2, the bit interleaved parity error report is calculated by comparing the BIP-8/24 code with the
BIP-8 code extracted from the B2 byte of the following frame. Differences indicate that line level
bit errors have occurred.
• For B3, the bit interleaved parity error report is calculated by comparing the BIP-8 code with the
BIP-8 code extracted from the B3 byte of the following frame. Differences indicate that path level
bit errors have occurred.
Step 5 Check the Alarm indication signal (AIS) field.
• Line alarm indication signal is sent by the section terminating equipment (STE) to alert the
downstream line terminating equipment (LTE) that a LOS or LOF defect has been detected on the
incoming SONET section.
• Path alarm indication signal is sent by the LTE to alert the downstream path terminating equipment
(PTE) that it has detected a defect on its incoming line signal.
Step 6 Check the Remote defect indication (RDI) field.
• Line remote defect indication is reported by the downstream LTE when it detects LOF, LOS, or AIS.
• Path remote defect indication is reported by the downstream PTE when it detects a defect on the
incoming signal.
Step 7 Check the Far end block errors (FEBE) field.
• Line far end block error (accumulated from the M0 or M1 byte) is reported when the downstream
LTE detects BIP(B2) errors.
• Path far end block error (accumulated from the G1 byte) is reported when the downstream PTE
detects BIP(B3) errors.
Step 8 Check the loss of pointer (LOP) Path field —LOP is reported as a result of an invalid pointer (H1, H2)
or an excess number of new data flag (NDF) enabled indications.
Step 9 Check the NEWPTR Inexact count field for of the number of times the SONET framer has validated a
new SONET pointer value (H1, H2).
Step 10 Check the PSE Inexact count field for of the number of times the SONET framer has detected a positive
stuff event in the received pointer (H1, H2).
Step 11 Check the NSE Inexact count field for of the number of times the SONET framer has detected a negative
stuff event in the received pointer (H1, H2).
Step 12 Check the Active Alarms field—It is a list of current Alarms as enforced by Sonet Alarm Hierarchy.
Step 13 Check the Active Defects field—It is a list of all currently active SONET defects.
Step 14 Check the Alarm reporting enabled field—It is a list of alarms that you enabled reporting for with the
pos report interface command.
Step 15 Check the COAPS fields—These are an inexact count of the number of times a new APS value has been
detected in the K1 and K2 bytes. These fields indicate the following: