The retransmission timeout plays an important role in allowing TCP to recover from segment losses. Over the years, extensions to TCP have been developed to reduce the reliance of TCP on the retransmission timer. Recently, a SIGCOMM paper proposed to use microsecond resolution timers in TCP. A recent IETF draft summarizes the discussions on TCP's retransmission timer, but surprisingly it does not discuss these microsecond resolution TCP timers.