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Term Definitions
823
Conceptually similar to SONET, since both share the goal of providing end-to-end
networking.
Out of Frame
A condition entered when four consecutive frames are received with invalid (errored)
framing patterns.
Out of Frame Event
Indicates the actual event of going from correct framing condition to an Out of Frame
condition. As soon as frame is lost, this is one OOF Event regardless of how long it
lasts.
Overhead (OH)
Extra bits in a digital stream used to carry information besides traffic signals. Orderwire,
for example, would be considered overhead information.
P
-P (Suffix)
Suffix indicating Path level.
Passthru
A function that allows an incoming signal to pass through the unit without altering the
data in the signal.
-PFE
Suffix indicating Path Far End (Remote Path).
Path Overhead
Those bytes placed in an STS-N (or OC-N) frame by the Path Terminating Equipment
and that stay with the frame through its whole transport across the transmission path.
The Path Overhead consists of the first 9-byte column of the Synchronous Payload
Envelope and contains the identification of the originating source of the traffic, a parity
check, path status, a signal label (identifying what type of traffic is in the payload
envelope), and a data communications channel.
PAT Sync
MPA_e_manual_D07-00-129P_RevA00