[closed] Which is the best protocol to test retransmissions over a wan link?

Hi, which is the best protocolo for test the number of retransmissions over a wan link? I did a test copying a file vía shared folders between a windows server 2008 and a windows seven client, but the first day the 2 mb file got transfered in 4 seconds without retransmissions and the second day there where like 25% number of packets utilized for retransmissions mechanisms (dup acks, retranmsmissions, fast retransmissions), it was not a bandwith problem. I didn't know that SMB is not the best protocol for WAN transfers, but my cuestion is that if I want to check the posible number of retransmissions over a WAN, wan protocol I can use to take those captures?

Regards!