[lwip-users] TCP not sending initial ACK

[Chuck Kuecker]

Hello,

 

I’ve got another problem. I am receiving a large (~132 K) HTTP file via TCP. The very first packet, which has the file length, is received, but not ACKed. The server times out and resends this packet, which is properly ACKed and all subsequent packets are handled properly.

 

I had this code working a couple of months ago, and something has changed since. I’ve tried changing the frequency of LWIP interrupt handler calls, both greatly slowing and speeding them up, with no apparent change in behavior. It’s only with TCP reception in this case that I see a problem. Other TCP exchanges work fine, with the same code structure in the two callback functions.

 

Any ideas?

 

Chuck Kuecker