Page 1139 - 5G Basics - Core Network Aspects

Transport aspects 2

 OTSiA-BDI-O

 OTSiA-TTI
 OTSiG-TSI

15.5.1 OCh and OTSiA forward defect indication – Payload (FDI-P)
For OCh and OTSiA trail monitoring, the OCh-FDI-P or OTSiA-FDI-P signal is defined to convey in the
downstream direction the OCh-P or OTSiG signal status (normal or failed).
15.5.2 OCh and OTSiA forward defect indication – Overhead (FDI-O)

For OCh and OTSiA trail monitoring, the OCh-FDI-O or OTSiA-FDI-O signal is defined to convey in the
downstream direction the OCh-O or OTSiG-O overhead signal status (normal or failed).
15.5.3 OCh and OTSiA open connection indication (OCI)

The OCh and OTSiA OCI is a signal sent downstream as an indication that upstream in a connection function
the OCh (i.e., OCh-P and OCh-O) or OTSiA (i.e., OTSiG and OTSiG-O) matrix connection is opened as a result
of a management command. The consequential detection of the OCh or OTSiA loss of signal condition at
the OCh or OTSiA termination point can now be related to an open matrix.
15.5.4 OCh-O transport over SOTUm interface

In the case of a MOTUm interface, the coding and method of OCh-O information transfer is vendor specific.
For a SOTUm interface, the OCh-O is transferred over the overhead communication network (OCN) as
described in [ITU-T G.7712].
NOTE – A SOTUm interface which transfers OCh-O over an OCN cannot provide fate-sharing of the OCh-O with the
OCh-P across this interface.
The OCh FDI-P, FDI-O and OCI Overhead primitives are communicated over the OCN. The specification of
the encapsulation, identification and transmission of this information is outside the scope of this
Recommendation and specified in [ITU-T G.7712]. This information must be communicated with the peers
such that the OCh-O primitives come into sync within one second in the absence of changes to OCh FDI-P,
FDI-O or OCI. In the event of changes to any OCh-O primitive, the update must be sent within 10 ms of the
change and with a mechanism to guarantee receipt in the event of packet loss.

15.5.5 OTSiA backward defect indication – Payload (BDI-P)

For OTSiA path monitoring, the OTSiA-BDI-P signal is defined to convey in the upstream direction the OTSiG
signal fail status detected in the OTSiG termination sink function.

15.5.6 OTSiA backward defect indication – Overhead (BDI-O)
For OTSiA path monitoring, the OTSiA-BDI-O signal is defined to convey in the upstream direction the
OTSiG-O signal fail status detected in the OTSiG-O termination sink function.

15.5.7 OTSiA trail trace identifier (TTI)
The OTSiA-TTI is defined to transport a 64-byte TTI as specified in clause 15.2 for OTSiA path monitoring.

15.5.8 OTSiG transmitter structure identifier (TSI)
The OTSiG-TSI is defined to transport a TSI for monitoring consistent configuration of the OTSiG
transmitter(s) at source end points and OTSiG receiver(s) at sink end points.

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