Lucent Technologies DDM-2000 OC-12 User Manual

363-206-295
Transmission and Synchronization Interfaces
Issue 1 December 1997 5-25
The sync quality unknown (SQU) message is sent to indicate where timing is
traceable to an external BITS and where it is valid to be used. Automatic
synchronization reconfiguration is not an option for externally timed DDM-2000
OC-3/OC-12 Multiplexers; therefore, a change in the synchronization message
will not cause an automatic synchronization reconfiguration.
The stratum level of the BITS clock at the CO (Site A) must be equal to or better
(more accurate) than the stratum level of the BITS clocks used at the other sites.
This is necessary to maintain the stratum level hierarchy.
Figure 5-9. Synchronization Reconfiguration — Externally Timed Access Ring
(Sheet 1 of 2)
SQU
SQU
SQU
SQU
DDM-2000
Site A
DDM-2000
Site B
DDM-2000
Site D
DDM-2000
Site C
BITS
CLOCK
BITS
CLOCK
BITS
CLOCK
SQU
SQU SQU
SQU
a) Synchronization Reconfiguration Example (Before Failure)
BITS
CLOCK
PRS Traceable
Source
Alternate PRS
Traceable Source

Lucent Technologies DDM-2000 OC-12 Specifications

General

Brand	Lucent Technologies
Model	DDM-2000 OC-12
Category	Multiplexer
Language	English