From: Ashwin [mailto:email@example.com
Sent: Thursday, December 16, 2010 4:55 PM
Subject: Re: [Madwifi-users] [SPAM] Madwifi v0.9.4 latest release: Frames
transmitted out of sequence
As it seems, the issue is more with the setup that you have. Maybe you
can try tweaking (increasing) buffers settings under sysctl ?
Could also be an issue with the "wired" interface with low buffers (in
the hardware itself). Use a very high quality ethernet card.
On 12/16/2010 01:21 PM, Mohan R wrote:
> Hi Dennis& Wayne,
> Thanks for your response.
> In my application I receive UDP/IPV4 packets from a wired interface. I
> no control on this protocol.
> My application has a peek of the data in frame, collects some statistics
> just forwards the frame over the wireless interface using dev_queue_xmit.
> One of the nodes is configured as AP& the other as Station. There is a
> sequence number associated with the payload. That is how I know that the
> packets are out of order when I receive them at the far end.
> I have Linux version 2.6.18 running on MIPS platform with AR5414A chipset
> based mini-PCI.
> When I started work on this application, I had examined the packet
> from the wired i/f. They seemed to be in order. I will verify this once
> My question now is are there any circumstances under which madwifi or
> dev_queue_xmit can reorder packets ?
> -----Original Message-----
> From: Wayne Johnson [mailto:firstname.lastname@example.org
> Sent: Wednesday, December 15, 2010 11:52 PM
> To: Dennis Borgmann; MOHAN.R.
> Cc: email@example.com
> Subject: RE: [Madwifi-users] [SPAM] Madwifi v0.9.4 latest release: Frames
> transmitted out of sequence
>> -----Original Message-----
>> From: Dennis Borgmann [mailto:firstname.lastname@example.org
>> Sent: Wednesday, December 15, 2010 5:39 AM
>> To: MOHAN.R.
>> Cc: email@example.com
>> Subject: Re: [Madwifi-users] [SPAM] Madwifi v0.9.4 latest release:
>> Frames transmitted out of sequence
>> Hi Mohan!
>> Maybe this is not an issue of madwifi, but an issue of you IP
>> Are you using UDP? If so, try TCP since it guarantees the sequence of
>> packet transmission.
>> Dennis Borgmann
> I don't think your statement is necessarily correct. With TCP, data
> leaving the transport layer and entering the application layer is
> guaranteed to be in order but packets can still arrive on the network
> layer out of order.
> It has been some time since I have done a lot of TCP/IP work but it is
> my understanding the out of order typically not a problem unless there
> is routing going on.
>> MOHAN.R. schrieb:
>>> Dear All,
>>> Occasionally I find that frames are being transmitted out of
>>> both AP as well as Station.
>>> This is not desirable for my application.
>>> Can anyone tell me why this happens and how to ensure that frames
>>> always sent in sequence.
> Without making quite a few assumptions it's not possible to even
> understand what you are asking here. A lot more detail is required. How
> are you sending the packets? How are you determining they are out of
> order? What hardware and software are you using on both ends? What are
> you trying to do?
> I don't want you to take this the wrong way, I am still trying to be
> helpful. Even though engineers are known for their literary skills ;-),
> answering questions still takes quite a bit of effort. I have found that
> most people try hard to be helpful when they can see that you are trying
> hard to figure it out. Most likely you are working very hard to figure
> out your problem but your email does not convey that and will probably
> be ignored by the people who (unlike me) can be most helpful.