Maintenance Description
Issue 8.0 July 2002
9-65
Synchronization Protection 9
General 9
The FT-2000 OC-48 Lightwave System provides three types of synchronization
protection: synchronization hardware protection, synchronization reference
protection, and synchronization mode protection.
Synchronization Hardware Protection 9
General 9
Synchronization hardware 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 9-10 shows the standard protection switching priorities in descending order
of priority used by the FT-2000 OC-48 Add/Drop-Rings Terminal.
The FT-2000 OC-48 Lightwave System provides protection for all the
synchronization circuit packs. The Timing Generator, Stratum 3 - DS1 [TG3
(DS1)] circuit packs are 1x1 protected and use revertive switching. The FT-2000
OC-48 Add/Drop-Rings Terminal must be equipped with two TG3 (DS1) circuit
packs on the Low Speed Shelf - System Controller.
FT-2000 OC-48 Add/Drop-Rings Terminal 9
Figure 9-22 shows the TG3 (DS1) circuit pack protection architecture of the
FT-2000 OC-48 Add/Drop-Rings Terminal.
Table 9-10. Synchronization Hardware Protection Switching Priorities
Switch Priority (Descending Order) Source of Request
Reset* CIT/OS
Circuit pack failure/removal Automatic
Manual switch CIT/OS
Circuit pack warming up Automatic
* Resetting the synchronization switch priority
(FAULT-Switch-Synchronization- Hardware-Priority:Reset) has no effect on
any automatic switch priority.