VeEX MPA User Manual page 839

MPA_e_manual_D07-00-129P_RevA00
Term Definitions
TU
For SDH, a Tributary Unit is an information structure which provides adaption between
the Lower-Order path layer and the Higher-Order path layer. It contains the VC, plus a
tributary unit pointer.
TUG
For SDH, a Tributary Unit Group contains several Tributary Units (TU)
U
UAS
Unavailable Seconds.
UAS-L
Near End Unavailable Seconds - Line. Reports the number of seconds that the Line
layer was considered unavailable. A line is unavailable when 10 consecutive seconds
that qualify as SES-L seconds occur.
UAS-P
Near End Unavailable Seconds - Path. Reports the number of seconds that the STS
path layer was considered unavailable. A path is unavailable when 10 consecutive
seconds that qualify as SES-P seconds occur.
UAS-PFE
Far End Unavailable Seconds. This is a counter that indicates the number of seconds
that an SES-PFE error was present at the far-end LTE. At least 10 consecutive errored
seconds of SES-PFE errors must be present before a UAS-PFE is declared.
UASR
Unavailable Seconds Ratio.
UDP
User Data Protocol.
UNEQ-P
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