lpcware

lwip

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by slavka012 on Tue Sep 17 10:19:04 MST 2013
I'm running lwip1.4.1 on lpc1788 and I'm having multiple issues. As I fix one, another appears....

Attached is a wireshark trace of the access to a single file. It is sort of working, but I have questions.

1. Why all of my packets have "Frame check sequence incorrect"? The incoming frames appear not to have that field. LWIP explicitly tells that it does not deal with ethernet CRC, which should be calculated in HW. However, it seems that EMAC on LPC1788 can only do that for short frames, under 60 bytes. Then it should be done in driver? Then how come there is no one else having this issue?

2. Why do I get so many duplicates and retransmissions? When I access an html file that has about 10 images in it, the number of duplicates grows exponentionally and seem to swamp the server.

3. This log is received when server is connected to a router (pc is wireless). When I connect server directly to a PC I don't see that many dups and retransmissions.

Any help would be greatly appreciated. If you need additional details I will provide.

Thanks,

Original Attachment has been moved to: lpc1788.zip

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