Re: [lwip-users] Delayed ACKs

[Sergio R. Caprile]

Your problem seems to correlate to lost frames problems.
It is common for vendor provided "demos" to pull just one frame out of
the Ethernet controller per int/poll, so they lose frames on high
throughput.
You have:
- an application using an API
- the lwIP stack
- its port to your architecture (OS and micro)
- a driver for some Ethernet chip.
- some task getting frames out of the chip and putting them to lwIP

You should remove the unknown variables first. Consider running a known
good application from the contrib tree, preferably for the same API you
use. Then you can check your port and driver with your vendor.
Also make sure the stack has not been altered by the vendor, otherwise
check with them.
There are restrictions on threading, and that depends on the API you
use, and if you use NO_SYS=0 or =1. I can only help on RAW API and NO_SYS=1