EXFO FTB-8510B Guia Del Usuario página 1151

OEI (Outgoing Error Indication): The OEI indicates errored blocks of
the outgoing VTn/VC-n (bit 6 of the N1 byte).
TC-IEC (Tandem Connection - Incoming Error Count): The TC-IEC
indicates the number of B3 parity violations detected at the TC Source
for STS-1 SPE/VC-3 and above (bits 1 to 4 of the N1 byte). Available for
HOP only.
0
1
2
3
4
5
6
7
8
0
0
0
0
0
0 (IAIS)
0
SONET/SDH Application
Number of BIP-8 violations
Common Tabs
Bit 1 Bit 2 Bit 3
0 0 0
0 0 0
0 0 1
0 0 1
0 1 0
0 1 0
0 1 1
0 1 1
1 0 0
1 0 0
1 0 1
1 0 1
1 1 0
1 1 0
1 1 1
1 1 1
TCM RX
Bit 4
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
501