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.
o Bits 1-2: even parity error checking BIP-2 for the tandem connection
o Bit 3: Set to “1”
o Bit 4: Incoming AIS indicator (0 = no defect; 1 = defect occurred before tandem connection)
o Bit 5: TC-REI indicating errored blocks caused in the tandem connection
o Bit 6: OEI indicating errored blocks of the egressing STS-1n
o Bits 7-8: operate in a 76 multi-frame structure;
Multiframe structure consists of;
o Frames 1-8 >Frame Alignment Signal (FAS)
o Frames 9-72 > The Access Point Identifier of the tandem connection (TC-API)
o Frames 73-76 > TC-RDI indicating defects that have occurred in the tandem connection to the far end
o 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
o Frames 73-76 > Reserved capacity
TX150 e-Manual D07-00-023 Rev A02
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