+ The timestamp upper "too-distant-future" limit
+ at the moment of invoking the Tx burst routine
+ can be estimated as ``tx_pp`` option (in nanoseconds) multiplied by 2^23.
+ Please note, for the testpmd txonly mode,
+ the limit is deduced from the expression::
+
+ (n_tx_descriptors / burst_size + 1) * inter_burst_gap
+