>From the wireshark, item 13, is a 1460 data resend,
but in terminal log, we confirmed the data is get, and ACK is also send to remote. So I think we just lost ACK. The problem is easy to meet in larger TSS 1460, but with 512 TSS , I could see the send/receive is very stable. But smaller TSS give a lower performance. If I increase the TSS, the resend cause the complete flow is low and not stable. I tried to make duplicate ACK sent to remote, so as to solve my current problem. I make resend ACK in different code, but still could not see the duplicate ACK in the server, so I think my changing is not correct. Kieran, could you guild me to add code for force send duplicate ACK THANKS. On Thu, Apr 15, 2010 at 5:49 PM, yueyue papa <[email protected]> wrote: > Kieran, > > thank you to review. > > > > On Thu, Apr 15, 2010 at 5:44 PM, Kieran Mansley <[email protected]> wrote: >> On Thu, 2010-04-15 at 15:32 +0800, yueyue papa wrote: >>> Hi All, >>> >>> I use lwIP in GPRS environment. Wireshark is setup in the server. I >>> find these information: >>> >>> lwip device <--------------------> server (Wireshark running there) >>> >>> if TSS = 512, the TCP stream is working very stable. >>> >>> if TSS = 1024, 1460, there is always TCP ACK lost in server. The >>> resend is always happen. >>> >>> The resend cause the performance down. >> >> Are you sure it is ACKs that are being lost rather than packets with >> payload? Could you post an example wireshark capture to show this? >> >>> Is there a solution I could configure lwIP make duplicate ACK send, so >>> as to decrease the ACK lost possibility? >> >> Not that I know of. >> >> Kieran >> >> >> >> _______________________________________________ >> lwip-users mailing list >> [email protected] >> http://lists.nongnu.org/mailman/listinfo/lwip-users >> > _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
