WIZnet Developer Forum

Data loss in reception

Hi,
I am using W7500S2E-R1 module with serial configurations - 384k baud, 8 bits, No parity, 1 stop bit and setting the module as TCP/IP client. While receiving files more than 1MB data from server, i consistently getting communication drop and loss of data in the middle of sending packets.

I was checking with the wireshark. After communication is established with (TCP parameter MSS=1460), the server starts to send a 1MB file with TCP packet of 1514 bytes at a time(payload = 1460). At one point, when the Server sends a TCP packet , the module doesn’t acknowledge the receiving data and so the server timesout and sends RST. In the receiving end, i get only half the bytes (around ~700 bytes). Other bytes are missing. I checked my application, it does went through any buffer overflow or any UART errors.

What might be the possible error?

How to reduce the transmission packet length to be send over TCP/IP in Wiz module?
For instance, if i want to reduce the Maximum segment size(MSS) in TCP protocol, what settings i have to do to the module?

Thanks in advance

Hello,

In case of W7500S2E-r1, mss cannot be set.
In case of the product which firmware is released, it can be set by modifying firmware.
But I do not think this is a solution to this problem.
Your serial applicatiion overflows and seems to be causing problems on the ethernet side.
So I recommend to change or modify serial application.

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