EXFO FTB-800 Series for FTB-1 - Manual (Page 329)

Test Results
NetBlazer 319
Quality Level (1588 PTP)
Quality Level (1588 PTP)
The quality level characterizes the clock quality in terms of network
synchronization.
From the Test menu, tap Results, and the Quality Level tab.

Last QL Received indicates the last Quality Level value received. The
pass/fail verdict is also displayed when both QL Mismatch Monitoring
and Pass/Fail Verdict check boxes are selected.

Last Change indicates the date and time of the Last QL has changed.

QL Mismatch Monitoring when selected (default) enables the Quality
Level mismatch monitoring.

Expected QL allows the selection of the Expected Quality Level value.
Available when the QL Mismatch Monitoring check box is selected.
Quality Level
value
PTP Clock
Class
Description
QL-PRS
(default)
80 Primary Reference Source Traceable (G.811)
QL-STU/UNK 82 Synchronized - Traceability Unknown
QL-PRC 84 Primary Reference Clock Traceable (G.811)
QL-ST2 86 Traceable to Stratum 2 (G.812 Type II)
QL-INV3 88 Quality Level Invalid 3
QL-SSU-A/TNC 90 Type I or V slave clock (G.812)
Traceable to Transit Node Clock (G.812 Type V)
QL-INV5 92 Quality Level Invalid 5
QL-INV6 94 Quality Level Invalid 6
QL-SSU-B 96 Type VI slave clock (G.812)
QL-INV9 98 Quality Level Invalid 9
QL-ST3E 100 Traceable to Stratum 3E (G.812 Type III)