Hi, Walter; Is my understanding of the usage of jitter reserved parameter in your new BIRD correct? Tx jitter if GetWave exists Usage Info/Out: jitter added by simulator Usage In/InOut: jitter added by model dll if no GetWave always added by simulator Rx jitter if GetWave exists and returns clock ticks Info/Out: jitter added by simulator In/InOut: jitter added by model dll if no GetWave, or GetWave exists but doesn't return clock ticks always added by simulator Thanks, Fangyi