Bill, what version of lwIP are you using? 1.3.0? On Tue, Oct 7, 2008 at 1:24 PM, bill <[EMAIL PROTECTED]> wrote:
> > Kieran Mansley wrote: > > >> Thank you for any feedback on this. > > >> > > > > > > I don't know of any timers that have that periodicity in lwIP. > > None. > > > It might > > > be useful to get a packet capture from just before the poor performance > > > that we could look at in ethereal - that might give a clue about why > the > > > performance is poor. > > > > > The first thing I would do is to check whether this is a real delay in > > your device or a simple TCP retransmission delay (i.e. the first > > response has a bad checksum or something like that and the PC has to > > wait for the device to retransmit). > > I strongly suspect the latter. > > Thanks to both of you. I wanted to add to lwIP_stats when retransmissions > occur so I know if something was missed or there are errors. I had trouble > finding where all of the error recovery retransmissions occur. > > Is putting debug traces in tcp_rexmit_rto sufficient to catch when they > occur? > > One point is truly interesting. I can send 10MB/S (1MB every 100mS) for > ~9.5 minutes, or sit for 9 minutes while sending the 836 byte "I'm here" > packet once per second and then start the 1MB/100mS transfers and at ~9:30 > it fails. There have been a few times that I've seen a program crash or > memory corruption but most often the drop in bandwidth is what starts > things > off, and it is repeatable (from 9:25 to 9:40). The time seems to start > then > the connection is made. It doesn't matter how long the firmware is running > before the connection takes place. The connection can be terminated from > the PC and reconnected and it still times out at 9:30 or so from the first > connection. It makes it seem like an uninitialized variable in the > connection management. > > Thank you. If I learn anything, I'll let you know. I must resolve this. > :-) > > Bill > > > > _______________________________________________ > lwip-users mailing list > [email protected] > http://lists.nongnu.org/mailman/listinfo/lwip-users > -- Michael Williamson 315-425-4045x230 www.criticallink.com
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