| Description | The current status of the APS group.
modeMismatch
Modes other than 1+1 unidirectional monitor protection line
K2 bit 5, which indicates the architecture and K2 bits
6-8, which indicate if the mode is unidirectional or
bidirectional. A conflict between the current local mode
and the received K2 mode information constitutes a
mode mismatch.
channelMismatch
This bit indicates a mismatch between the transmitted K1
channel and the received K2 channel has been detected.
psbf
This bit indicates a Protection Switch Byte Failure (PSBF) is
in effect. This condition occurs when either an inconsistent
APS byte or an invalid code is detected. An inconsistent APS
byte occurs when no three consecutive K1 bytes of the last 12
successive frames are identical, starting with the last frame
containing a previously consistent byte. An invalid code occurs
when the incoming K1 byte contains an unused code or a code
irrelevant for the specific switching operation (e.g., Reverse
Request while no switching request is outstanding) in three
consecutive frames. An invalid code also occurs when the
incoming K1 byte contains an invalid channel number in three
consecutive frames.
feplf
Modes other than 1+1 unidirectional monitor the K1 byte
for Far-End Protection-Line failures. A Far-End
Protection-Line defect is declared based on receiving
SF on the protection line.
extraTraffic
This bit indicates whether extra traffic is currently being
accepted on the protection line. |