[lwip-users] Can I tune the retransmit configuration?
From:
Chen
Subject:
[lwip-users] Can I tune the retransmit configuration?
Date:
Mon, 22 Nov 2010 13:29:33 -0500
Hi All,
Please see the packet capture file attached:
My lwip-based device is sending out packets of 1200 byte at a rate of
around 64Kb/s, and the PC will ACK once for every two packets sent
out by lwip.
At packet 148, the ACK from the PC may have lost on the wire (I can only
assume this since wireshark can't capture exactly what my hardware is
actually seeing), and lwiP retransmit at 149.
Since my transmit buffer is not that big, the wait between packet 148 to
149 is too long (1 sec), my buffer overflow and the data stream has a
glitch.
Nothing is really wrong with lwip's handling, I have to say
But in my other project, their tcp will keep sending out data to pc, even
though a single ACK is lost, and since the PC will send another ACK after
two more packets, everything is back in sync again once the newer ACK
arrives. The retransmit will be triggered only after a programmable
time-out period is reached and we still haven't received any
ACK.