Excalibur ISX 5312, Руководство по эксплуатации

Страница: 166 / 228

Excalibur ISX 5312/5314 T-1 Multiplexer Installation and Operation
5-26
Table 5-1. ISX 5312/5314 Error Statistics
Statistic Definition
CRC-6 Error Event A CRC-6 error event occurs when the CRC-6 field
calculated by the ISX 5312/5314, based on the
incoming DS1 signal, does not agree with the DS1
signal received from the network.
Out of Frame (OOF)
Not reported as a
separate event An OOF begins when any two of five consecutive
frame synchronizing bits received from the network
interface are incorrect. An OOF state ends when
reframe occurs.
ESF Error Event
Not reported as a
separate event Each ESF is examined for an error event. An ESF
error event is determined by the logical ORing of a
CRC-6 error event and the occurrence of an OOF.
Errored Second (ES) An ES is a second with one or more ESF error events;
that is, one or more CRC-6 error events, or one or
more OOFs, or one or more Controlled Slips (CSs).
Severely Errored
Second (SES) An SES is a second with 320 or more CRC-6 error
events or one or more OOFs.
Bursty Errored
Second (BES) A BES is a second with more than 1, but less than 320
CRC-6 error events.
Loss of Frame Count
(LOFC) An LOFC is the accumulation of the number of times
a "Loss of Frame" condition is declared.
Loss of Frame Declare: On detection of an LOS or
OOF, a rise slope type integration process starts that
declares a Loss of Frame after 2.5 (
±
0.5) seconds of
continuous LOS or OOF. If the LOS or OOF is
intermittent, the integration process shall decay at a
slope of 1/5 rise slope during the period when the
signal is normal. Thus, if the ratio of a LOS or OOF
to a normal signal is greater than 1/5, a Loss of Frame
will be declared.
Loss of Frame Clear: Clear a Loss of Frame if in at
least a 1-second interval, but no more than 15
contiguous 1-second intervals, no LOS or OOF
conditions occur.