This counts the number of times a duplicate FCIP Special Frame was received on this link -- the same handshake frame arriving more than once. Duplicates during the handshake phase often indicate retransmission happening at the IP/TCP layer due to a lossy or high-latency path, or overlapping connection setup attempts, either of which is worth correlating with the link's TCP-level statistics for the same connection. A rising count here alongside a low TCP receiver window and long round-trip time on the same link's TCP connection stats would together suggest the handshake is being slowed and retried due to underlying network latency rather than a configuration bug.