VeEX MPA User Manual page 821

MPA_e_manual_D07-00-129P_RevA00
Term Definitions
To transmit two or more signals over a single channel.
N
N2 byte
Allocated for Tandem Connection Monitoring for the VC2, VC-12, and VC-11 level.
NDF
New Data Flag. The first four bits of the Payload Pointer in the Transport Overhead
portion of the Synchronous Transport Frame. These bits indicate a change in the
payload, and thus a change in the Payload Pointer.
NPJ
Negative Pointer Justification.
NPJC
Negative Pointer Justification Count.
O
OA1
The OTU FAS is a 6-byte structure that occupies row 1, columns 1 to 6 of the OTU
overhead. The first three bytes (columns 1 to 3) of the OTU FAS are OA1. The default
value is 111 0110.
OA2
The OTU FAS is a 6-byte structure that occupies row 1, columns 1 to 6 of the OTU
overhead. The second three bytes (columns 4 to 6) of the OTU FAS are OA2. The
default value is 0010 1000.
OC
A SONET optical signal. Results from direct electrical-to-optical mapping of the
corresponding STS signal. The base rate for OC signals is 51.84 Mbps (OC-1).
OC-1
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