I tried on a MacBook Pro i7 8GB and on a Lenovo Y50 i7-4720, 16GB of RAM, same problem!
The network is a based on an Asus RT-N16, Server-Router is 1GB/s and Computer-Router is 100MB/s (pass through a Cisco 7940 in switch mode). I also tried the computer in wifi mode, and on an external network using NAT.
Thanks!