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ATCA-F125 (6873M Artwork) Installation and Use (6806800J94N)
Functional Description
Functional Description
4.11.2
BITS/SSU Support
Many facilities where the ATCA-F125 is likely to be deployed, such as central offices, will
include a central Building Integrated Timing Supply (BITS) or Source Synchronization Unit
(SSU).
A BITS is typically an output-only device that provides a precision timing reference, known
as the T[3] clock, to shelf-level products that use this for synchronizing the local telecom
clocks. An SSU is similar to a BITS but can in turn synchronize itself to a linecard derived
reference known as a T[4] clock.
The ATCA-F125 provides dual T1/E1 interfaces to support both BITS and SSU operation.
Figure 4-13 BITS/SSU Clock Flow
