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Liaison statement
LS on ITU-T Q14/15 work on the management model for time and frequency synchronization

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State Posted
Submitted Date 2016-03-08
From Group ITU-T-SG-15
From Contact Hiroshi Ota
To Group tictoc
To Contacts Yaakov Stein <>
Karen O'Donoghue <>
Cc Terry Manderson <>
Scott Mansfield <>
Yaakov Stein <>
John Drake <>
Timing over IP Connection and Transfer of Clock Discussion List <>
Brian Haberman <>
Karen O'Donoghue <>
Response Contact
Purpose For information
Attachments LS on ITU-T Q14/15 work on the management model for time and frequency synchronization
ITU-T Q14/15 has initiated work on the development of a protocol neutral
information model in UML to support the management of both time and frequency
synchronization. Q14/15 also plans to map the UML model into a YANG data model
for the management of time synchronization. This work does not cover time of
day distribution (e.g., using NTP).

Management view of the synchronization network

A NE that supports a slave clock function (i.e. a local frequency or time
reference) will terminate a number of interfaces that support trails and links
in one or more layer networks. These link may support user traffic and/or
synchronization information.

As described in Appendix A, the synchronization distribution trails will be
present within some of these interfaces. The selection of the synchronization
input and the distribution of the output of the slave clock are independent.
For example at the edge of a network a NE may have two links that support an
incoming synchronization signal but the output of the slave clock would not be
distributed to other NEs. It is more convenient to describe and model
synchronization using uni-directional constructs.

Please see attachment for liaison details.