We seem to have a problem when using LWIP 1.3.2 to request a large file
from a remote server. Our target is an ST7101 running OS21.
Our application uses the netconn API to request a large file from a
remote server using HTTP GET
From what I can see from Wireshark, the transfer begins OK with correct
ACK's being sent.
However at what appear to be random points during the transfer, I start
to see duplicate ACK's. It seems LWIP is sending the same ACK for the
next few segmemts it receives.
I have experimented with adjusting the TCP_WND size in lwipopts.h with
mixed results. It would appear that if TCP_WND > 8*TCP_MSS, then we
start seeing the duplicate ACK problem. TCP_MSS is set to 1460. However
having a lower TCP_WND size results in a lower transfer performance.
I have attached a text file containing the Wireshark export.
Any help would be greatly appricated.
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