EXFO FTB-8510B Guia Del Usuario página 931

Bit-Oriented Messages
The Bit-Oriented Messages are priority messages sent over the Data-Link.
These messages are mostly used for networking operation and
maintenance. A Bit-Oriented Message consists of 8 consecutive ones
followed by a byte starting and ending by zeros.
Priority
On/Off allows generating the selected codeword priority message.
SONET/SDH Application
Priority Codeword
RAI
Loopback Retention and Acknowledge 00101010 11111111
RAI-CI
Pattern
00000000 11111111
00111110 11111111
DSn Tabs
FDL TX
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