Man-Machine E1 maintenance interface software 309Figure 73Display Status (D S) screenPerformance counters and reportingThe MMI monitors the performance of the E1 link according to severalperformance criteria including errored, bursty, unavailable, loss-of-frameand frame-slip seconds. It registers the performance of these criteria byreading their status every second and counting their results. These countsare accumulated for an hour, then reset to 0. Previous hour count resultsare maintained for each of the previous 24 hours.The LEI counts CRC-4 errors when CRC-4 is enabled and Bipolar Violations(BPV) when CRC-4 is disabled. The performance criteria for which thesecounts are maintained as follows:• Errored seconds are seconds in which one or more CRC-4 / BPV errors,or one or more out-of-frame errors in one second.• Bursty seconds are seconds in which more than one and less than 320CRC-4 / BPV errors in a second.• Severely errored seconds are seconds in which more than 320 CRC-4 /BPV errors, or one or more out-of-frames in a second.• Unavailable seconds are seconds in which unavailable state starts with10 consecutive severely errored seconds and ends with 10 consecutivenon-severely errored seconds (excluding the final 10 non-severelyerrored seconds).• Loss-of-frame seconds are seconds in which loss-of-frame orloss-of-signal conditions exist for three consecutive seconds.• Frame slip seconds are seconds in which one or more frame slips occur.The MMI also maintains an overall error counter which is the sum of allerrors counted for the performance criteria listed above. The error countercan only be cleared by entering the Clear Error (C E) command. Itstops counting at 65,000. The error counter provides an easy methodNortel Communication Server 1000Circuit Card ReferenceNN43001-311 01.04 StandardRelease 5.0 23 May 2008Copyright © 2003-2008, Nortel Networks.
