VeEX MPA User Manual page 825

MPA_e_manual_D07-00-129P_RevA00
Term Definitions
PLM
Payload Label Mismatch alarm.
PM
Path Monitoring
Pointer
The Payload pointer indicates the offset between the VC payload and the STM-N frame
by identifying the location of the first byte of the VC in the payload. In other words, the
VC is allowed to "float" within the STM-1 frame capacity.
PTR-ADJ
Pointer Adjustment. In the Quick Status LEDs area, an event LED indicating a Pointer
adjustment has been received.
Pointer Value
The offset in bytes from the pointer to the first byte of the VC, which is the J1 byte.
Because the Section Overhead bytes are not counted, and starting points are at 3-byte
increments for a VC-4 payload, the possible range is: Total STM-1 bytes minus Section
Overhead bytes = Pointer value range.
PoS
Packet over SDH/SONET. Uses SONET/SDH as the Layer 1 (physical layer) protocol,
encapsulating IP or other packet traffic in High Level Data Link Control (HDLC) frames
and using Point-to-Point Protocol at Layer 2 (data link layer), with IP traffic running at
Layer 3 (network layer). See section on SONET Versus SDH Terminology.
Power Loss Alarm
The duration that the unit was without power (turned off) during a Real-Time test.
P-Parity Error
An error in the P-bit channel (P1 and P2) that provides parity information for the
preceding M-frame.
PPJ
Positive Pointer Adjustment.
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