Re: wi problem with message > 7400 bytes

On Thu, 30 Oct 2003, Lars Eggert wrote:

> Daniel Eischen wrote:
> 
> > Greetings,
> > 
> > I'm having a problem receiving UDP messages over a wi interface:
> > 
> > wi1: <Dell TrueMobile 1150 Series PC Card> at port 0x180-0x1bf irq 11 function 0 config 1 on pccard0
> > wi1: 802.11 address: 00:02:2d:4a:d8:7d
> > wi1: using Lucent Technologies, WaveLAN/IEEE
> > wi1: Lucent Firmware: Station (6.10.1)
> > wi1: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
> > 
> > (wi0 is also a 'Dell TrueMobile 1150 Series PC Card' in
> >  a mini-PCI card, but hangs the system when you try and
> >  configure it -- so it obviously isn't configured in this
> >  set up.)
> > 
> > I have a small program that does a trivial UDP test:
> > 
> >   http://people.freebsd.org/~deischen/udptest.c
> > 
> > My results show that:
> > 
> >   o Receiving large (> 7400 bytes) messages does not work.
> > 
> >   o Sending large messages works.
> > 
> >   o Sending & receiving large messages over a wired
> >     interface (dc, fxp, etc) works.
> > 
> > Am I suppose to be able to receive UDP messages larger
> > than 7400 bytes over the air?
> 
> Could you post a tcpdump for each case? I wonder if this is related to a 
> fragmentation issue I've seen in the past.

22:46:43.513038 gpz.foo.bar.com.38340 > vespa.12345: udp 7393 (frag 52198:1480_at_0+)
22:46:48.522475 gpz.foo.bar.com.38340 > vespa.12345: udp 7393 (frag 52199:1480_at_0+)
22:46:53.532018 gpz.foo.bar.com.38340 > vespa.12345: udp 7393 (frag 52200:1480_at_0+)
22:46:58.541178 gpz.foo.bar.com.38340 > vespa.12345: udp 7393 (frag 52201:1480_at_0+)
22:47:03.553048 gpz.foo.bar.com.38340 > vespa.12345: udp 7393 (frag 52202:1480_at_0+)
22:47:08.568862 gpz.foo.bar.com.38340 > vespa.12345: udp 7393 (frag 52203:1480_at_0+)
22:47:13.583328 gpz.foo.bar.com.38340 > vespa.12345: udp 7393 (frag 52204:1480_at_0+)
22:47:18.578512 gpz.foo.bar.com.38340 > vespa.12345: udp 7393 (frag 52205:1480_at_0+)
22:47:23.609098 gpz.foo.bar.com.38340 > vespa.12345: udp 7393 (frag 52206:1480_at_0+)
22:47:28.597680 gpz.foo.bar.com.38340 > vespa.12345: udp 7393 (frag 52207:1480_at_0+)
22:47:33.607059 gpz.foo.bar.com.38340 > vespa.12345: udp 7393 (frag 52208:1480_at_0+)

In this case, I ran:

  gpz $ udptest -D -c -a 192.168.3.31 -m 7393

  vespa $ udptest -D

vespa (192.168.3.31) is the affected notebook with wi interface.
I ran udptest as the server, so all it is doing is trying to
receive a message.  The tcpdump was done on vespa.

The kernel is current from Monday or Tuesdays sources, and
I had the same problem with a kernel from August.

-- 
Dan Eischen