[lwip-users] Re: curious large packets and transmit stuck

[Andre Puschmann]

hi kieran,
here are my lwip opts.h and one trace using the netconn-api and another
one using the raw api ..
if you have a look at the first trace (netconn) you can see that the
packets slowly dropping out/in .. it seems that lwip "forgets" acks the
other end send. you can't see the large packets directly, i mean there
is one large and another small one, but before the stuck all packets
were 1000bytes long. so it seems that it has something to do with that.
if i use the raw api there are no "large" packets .. since as long as
lwip has something to send it sends packet with max size (1456byte). but
nevertheless, after a while the whole system shows the same behavior.

do you think it has something to do with my timer/semaphore/mbox
implementation?


many thanks

andre



1: http://www.puschmann.net/public/dropping_packets_rawapi.cap
2: http://www.puschmann.net/public/large_and_small_packet.cap
3: http://www.puschmann.net/public/opt.h


Kieran Mansley wrote:
> On Tue, 2007-01-30 at 21:56 +0100, Andre Puschmann wrote:
>> i am aware of this fact. the curious thing IMO is the correlation
>> between the occurrences of this "larger packets" and the stuck of the
>> whole stack.
> 
> Sounds like you may either have a locking problem (the usual cause of
> deadlock) or possibly a resource allocation issue.  Is lwIP sending or
> receiving the large packet?  Could you get a packet trace using
> something like ethereal?  Your lwipopts.h configuration might throw some
> light on the problem too.
> 
> Kieran