This read-write timer, in milliseconds, sets the Distributed_Services_Timeout Value (D_S_TOV), which governs how long a distributed Fibre Channel service requester on this switch waits for a response before giving up. An administrator tunes this in fabrics with longer inter-switch latency to avoid premature timeouts on distributed service requests. For example, in a fabric spanning a longer-distance link, increasing fcTimerDstov prevents distributed services from timing out simply due to added round-trip delay.