Alcatel-Lucent 9500 MXC, Руководство пользователя

Страница: 193 / 916

9500 MXC User Manual
3DB 23063 ADAA - Rev 004 July 2007 Vol. II-3-99
• Rx synthesizer not locked
• Rx IF synthesizer not locked
• Demodulator not locked
• ODU Tx cable IF synthesizer not locked
• 10
-6
BER (user-selectable wrap and/or unwrap options)
• RAC plug-in is missing
• RAC software load failure
Fiber (DAC 155oM) Wrap Conditions
Conditions for ring wrapping:
• Loss of SDH/SONET frame
• DAC 155oM plug-in is missing
• DAC 155oM software load failure
Wrap and Unwrap Times
The wrapping process is performed without any participation of the alarmed
RAC or DAC 155oM, or potentially failed RAC/DAC in the instance of a silent
transmitter failure.
Ring wrapping and unwrapping is not hitless:
• 100 ms maximum service restoration time (detection, switching and recovery)
for a ring wrap based on a 16-hop ring, which is the maximum recommended
ring size. It will typically be between 40 and 100 ms, depending on the number
of hops and ring capacity; the higher the capacity, the lower the ring delay.
• The revertive switch command for return to normal service is initiated after the
relevant alarms on the failed link have been cleared for a period set by the
Error-Free Timer (default 5 minutes), or by the optional Delay Ring Unwrap
Timer, which sets a time of day for an unwrap. Full restoration of normal traffic
(unwrapped) on the ring occurs within 100 ms of receipt of the revertive switch
command.
Unwrap Timers
An
Error-free Timer
in the Protection configuration screen sets the period of
error-free operation needed prior to initiation of an unwrap. When a wrap has
occurred this timer counts down towards an unwrap as soon as all wrap
conditions are cleared. The count begins anew should a wrap condition re-occur
during the countdown. The time options are 10 seconds, or 1, 5, or 10 minutes. 5
minutes is default (recommended).
A
Delay Ring Unwrap
timer in the Protection configuration screen allows