EXFO FTB/IQS-88000 Series Power Blazer for FTB-2/2Pro/500/IQS-600 - Manual (Page 477)

Test Functions
Power Blazer 465
OH - SONET/SDH

For OC-768: The combination of the M1 byte located in the
STS-1 #7 and the M0 byte indicates BIP violations.
Z2: Growth. Available with OC-3, OC-12, and OC-48 signal, this byte is
located in STS-1 #1 up to STS-1 #48 except for timeslots used by M0
and M1.
Undefined “--” for all other timeslots not covered by M0, M1, and Z2.

M0 or M1 (SDH)
M0: MS-REI. STM-1 channel #1 of a STM-0 signal; channel #2 of an
STM-64/STM-256 signal.
M1:MS-REI. STM-1 channel #1 of a STM-1 signal; channel #3 of an
STM-N signal (N>1).
Undefined “--” for all other channels not covered by M0, and M1.

E2
1
: Orderwire. Provides a 64 Kbit/s voice channel for communication
between LTEs.
M0
Located in STS-1 #4
M1
Located in STS-1 #7
Indicates
0000 0000 0000 0000 0 BIP violation
0000 0000 0000 0001 1 BIP violation
: : :
0001 1000 0000 0000 6144 BIP violations
0001 1000 to
1111 1111
0000 0001 to
1111 1111
0 BIP violation
1. This byte is only defined for the first STS-1/STM-1 frame of a composite signal.