I have two ESP32 sending data more or less simultaneously to a server over WIFI. If one of the ESP is further away (i.e. is close to the border of it's connection range) than wireshark running on the server shows spurious retransmissions. This means that the ESP sends data to the server, the server sends back an acknowledgment but the ESP does not receive the ACK in time or not at all. So the ESP sends the data again and the server acknowledges it again. This is called a spurious retransmission.
This behaviour might be normal since the ESP is further away. What is weird now is that the second ESP (in close proximity to the server) does the same thing just after it started with the first ESP.
The server is a windows machine creating a hotspot via a virtual hosted network adapter with the IP: .137.1. The ESPs have the IPs .137.100 & .137.102.
- wireshark3.png (64.65 KiB) Viewed 4210 times
Since the server actually received the data but the ESP didn't get the ACK (in time?) might it be possible to increase the retransmission timeout of the ESP?
Thanks and best regards
*Edit*
Setting TcpAckFrequency to 1 in the Windows registry has helped dramatically!