Specifications

IPmux-1/1E Installation and Operation Manual Chapter 4 Troubleshooting and Diagnostics
Performance Monitoring and Troubleshooting Statistics 4-9
Table 4-3 E1/T1 Alarms (Cont.)
Alarm Description
FEBE A Far End Block Error is sent to transmitting device notifying that a flawed block has been
detected at the receiving device. Exists only for E1 MF-CRC4.
The FEBE counter will increase by one for each second during which the FEBE indication is
received.
Recommendation:
Check physical link integrity.
BES A Bursty Errored Seconds (also known as Errored second type B) is a second during which
fewer than 319 and more than one CRC errors occurred with neither AIS nor SEF (Severely
Errored Frame) detected. The BES counter will increase by one for each second containing
the condition described above. The CRC is calculated for the previous frame in order to
prevent processing delay.
Complies with AT&T TR-62411 and TR-54016 standards.
Not applicable if the line type is set to Unframed.
Available only at T1-ESF or E1-CRC4 modes (performance monitoring functionality).
Recommendations:
Check physical link integrity, G.704 frame format integrity and Sync. (The CRC bits are
included in TS0 for E1 multi-frame links and in the frame alignment bits for T1 ESF links).
DM A Degraded Minute is calculated by collecting all the available seconds, subtracting any SES
and sorting the result in 60-second groups.
The DM counter will increase by one for each 60-second group in which the cumulative
errors during the 60-second interval exceed 1E-6.
Available in T1-ESF or E1-CRC4 modes only, (performance monitoring functionality).
Recommendations:
See BES recommendations.
ES An Errored Second is a second containing one or more of the following:
CRC error
SEF (OOF)
AIS (T1 only)
If SES is active ES runs for 10 seconds and then stops.
Recommendations:
Check physical link integrity. Follow the recommendation concerning LOF, BEF and AIS.