VeEX VePAL TX300M, User Manual

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J2 byte (VT path trace)
Used to transmit a configurable 16-byte identifier that enables the receiving path to continuously verify its
connection with the transmitter
Uses the same byte structure as the J0 and J1 bytes
Z6 byte (VT-TCM)
Provides VT tandem connection monitoring function (TCM-V) for the VT-1.5, VT-2 levels.
Bits 1-2: even parity error checking BIP-2 for the tandem connection
Bit 3: Set to “1”
Bit 4: Incoming AIS indicator (0 = no defect; 1 = defect occurred before tandem connection)
Bit 5: TC-REI indicating errored blocks caused in the tandem connection
Bit 6: OEI indicating errored blocks of the egressing STS-1n
Bits 7-8: operate in a 76 multi-frame structure:
Multiframe structure consists of:
Frames 1-8 > Frame Alignment Signal (FAS)
Frames 9-72 > The Access Point Identifier of the Tandem Connection (TC-API)
Frames 73-76 > TC-RDI indicating defects that have occurred in the tandem connection to the far-end
Frame 74 > ODI indicating to the far-end that AIS-P/V has been inserted into egressing STS-1n VT-n due to
defects before or within the tandem connection
Frames 73-76 > Reserved capacity
Z6 Byte (VT-TCM)
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