[lwip-users] Problem of tcp_write with more then about 20 kBytes

[Daniel Klingler]

Hi,

I am using LWIP 1.3 with Xilinx (SDK).

My settings:
- TCP_SND_BUF 64240
- TCP_MSS 1460

My problem:
- If I am do tcp_write with 18720 Bytes the transfer is well going.
- If I am writing with 19968 Bytes the transfer with some PCs is well going,
but with other PCs the return of tcp_write is -1.
- If I am writing with 21504 Bytes or more then with all connected PCs I
will return -1 of tcp_write.

Does anybody know this issue or has any idea to solve this?

Thanks for your replies.
Regards,
Daniel