However with the windows scaling factor it informs the peer of 2^16+2^16 windows size so that it could send more data in one go. As I am yet to receive an update from our engineering team can we try enabling Windows Scaling factor along with SACK to see the behavior. This possibly might address the slowness issue were data received could increase for the client and could give better performance. I couldn’t see any other issue in the working and non-working trace. The communication is working fine as expected. I would suggest to test this during off peak hours, since enabling windows Scaling would inform the Server/Client that more amount of data could be sent in one go. This should not affect much, but it’s safe to test during off peak hours.