Check POS interface state with "display interface pos" command and there is B1, B2 and B3 under SDH error, what is their meaning?
For the output of display interface pos, there is B1, B2 and B3 under SDH error. e.g.
<NE80E>displsy interface pos 1/0/0
Pos1/0/0 current state : UP
Line protocol current state : UP
section layer: B1 463371
line layer: B2 29095741 REI 220764795
path layer: B3 1208277
B1: bit interleaved parity order 8, BIP-8
B2: multiplex section BIP-24. Except RSOH, parity check before scramble and it is used for bit error monitoring of multiplex monitoring.
REI: Remote Error Indication
B3: channel BIP-8. B3 is to monitor error performance of VC4 transmission in STM-N, namely, error performance of 140mb/s signal in STM―N. It is similar to B1 and B2. B3 has BIP―8 check for VC4 frame.