The docs specify for DDS_BY_SOURCE_TIMESTAMP_DESTINATIONORDER_QOS that samples will be dropped if they've got a timestamp "in the future" and where that threshold is set by source_timestamp_tolerance.
What's the default value for source_timestamp_tolerance?
The defaults are described in our API docs. source_timestamp_tolerance is 100ms for datawriters and 30 seconds for datareaders (at least for Connext version 6.1.1, you may want to check your specific version's API docs)
https://community.rti.com/static/documentation/connext-dds/6.1.1/doc/api/connext_dds/api_cpp/structDDS__DestinationOrderQosPolicy.html#a692d1a1f1117dbb9eadb980a41f8a156
source_timestamp_tolerance has a difference meaning (and default value) depending on if it is being set within the DataReaderQos or the DataWriterQos. I think you are asking about the DataReaderQos, but I will give you both:
Within the DataReaderQos, the default is 30 seconds. Here it represents the maximum allowed separation between the source timestamp and reception timestamp of a sample (assuming source timestamp is further in the future than the reception timestamp). So if the reception timestamp is 16:13:01, the source timestamp cannot be furhter in the future than 16:13:31.
Within the DataWriterQos, the default is 100 milliseconds. If a DataWriter writes a sample at time X, the next sample it writes cannot be more than source_timestamp_tolerance in the past (e.g., X - 100 ms). If the sample being written is in the past, but within the tolerance, the previous sample's timestamp is used.
This is documented in the API reference (e.g., for 6.1.0, C API)
Note that all of the above only applies if the destination order kind is set to BY_SOURCE_TIMESTAMP.
Thank you - I did search for source_timestamp_tolerance without finding those default values. I'm grateful for your reply.