I'm wondering how CTT in OPC UA test center evaluates the statement "This error may be suppressed" in OPC UA Part 4, Release 1.04, Table 106 - Certificate Validation Steps.
For example in "Validity Period" step the statement is applicable. I could imagine this error might occur if the OPC UA Server under test is not equipped with a working time synchronization solution such as network time protocol (NTP). If this is the case then would the Server implementation fail the conformance test?
the "May be Suppressed" is indicating that an application may provide a configuration option to temporarily suppress this check. This is no requirement for an application to have such an option. Therefore, an application not having this option would be considered compliant. If an application does provide this option, the testing makes sure that it is not activated by default.
Regarding the certificates, the CTT is generating certificates which already expired for those tests.
I hope this helps.