We've recently dealing with a problem in the network that points out to client issues but unfortunately that is totally not possible as if we switch from corporate network and use VPN GW instead (without using Branch to DC path) it works every single time.
What I can see in the packet captures is that client stops sending ACK to the server after a certain interval in the transaction. The server sends ~500 packets after the last ACK we see from the client on the client capture. Server then waits 300ms (for ACKs) and start retransmisson based on last ACK seen. After 3 retries it sends a reset. After a delay of ~30s the client sends the next ACK (after last one) but with len=1 (window length).
Any ideas of what I should look for? This started when the WAN device was changed on both of the branches which have problems.
