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Path Overhead
The Path Overhead (POH) is a 1 byte field in a DS3 PLCP frame that provides specific functions. The Z bytes
Path Overhead Identifier (POI)
The Path Overhead Identifier (POI) is the label for the function of each Path Overhead byte in a PLCP frame.
POI - POI Value (8 bit) | POH | ||
P11- | 00101100 | Z6 | |
P10- | 00101001 | Z5 | |
P9 | - | 00100101 | Z4 |
P8 | - | 01000000 | Z3 |
P7 | - | 00011100 | Z2 |
P6 | - | 00011001 | Z1 |
P5 | - | 00010101 | X |
P4 | - | 00010000 | B1 |
P3 | - | 00001101 | G1 |
P2 | - | 00001000 | X |
P1 | - | 00000100 | X |
P0 | - | 00000001 | C1 |
Payload
The payload of an ATM cell is the 48 bytes available for data. This field is also called the Cell Payload or Data Payload.
Payload Type (PT)
A field in the header of an ATM cell used to identify the type of information being transported that may require different handling by the network or terminating equipment.
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