Lucent Technologies FT-2000 OC-48 User Manual

Maintenance Description
Issue 8.0 July 2002
9-71
Synchronization Mode Protection 9
Synchronization mode protection switching occurs in response to automatically
detected faults and external commands from a local/remote CIT or operations
system. Refer to the FAULT-Switch-Synchronization input in Volume I,
Section 11, "Craft Interface Terminal Usage."
Table 9-12 shows the standard protection switching priorities in descending order
of priority used by the FT-2000 OC-48 Add/Drop-Rings Terminal.
If the FT-2000 OC-48 Add/Drop-Rings Terminal is provisioned to operate in the
through timed mode, or externally timed mode (phase locked in releases prior to
Release 5) and all reference signals fail, the TG3 (DS1) circuit pack holds the
on-board oscillator frequency at the last good reference sample (holdover mode)
until the DS1 reference signals are repaired. In the holdover mode, the on-board
oscillator frequency will not degrade below the stratum 3 level.
Table 9-12. Synchronization Mode Protection Switching Priorities
Switch Priority (Descending Order) Source of Request
Reset* CIT/OS
Forced switch CIT/OS
Synchronization reference failure Automatic
* Resetting the synchronization switch priority
(FAULT-Switch-Synchronization- Mode-Priority:Reset) has no effect
on any automatic switch priority.

Lucent Technologies FT-2000 OC-48 Specifications

General

Brand	Lucent Technologies
Model	FT-2000 OC-48
Category	Network Hardware
Language	English