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List:       linux-usb-devel
Subject:    Re: [linux-usb-devel] babble errors
From:       Johannes Erdfelt <johannes () erdfelt ! com>
Date:       2002-03-28 0:00:55
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On Wed, Mar 27, 2002, Petko Manolov <pmanolov@Lnxw.COM> wrote:
> Johannes Erdfelt wrote:
> > I understand that when it receives a 0 packet, it handles the packet
> > correctly, but does it *send* a 0 packet when it's transferring to the
> 
> It is not mentioned anywhere in the documentation, and i don't get
> packets with 0 length from the device.  I have code which warns me
> about any packet less than 64 bytes and i didn't see any with payload
> 0.

You're confusing two things here. I'm talking the lower level USB
packet. You won't see those returned to you.

There's typically many of those per logical packet that you receive (or
in your case, ethernet frame).

> > When you say 1090 bytes long, is that the size of the packet, or the
> > size of the data it sends? I presume there's some sort of header that it
> 
> It is the raw ethernet packet - everything.  Later tcp/ip layer strips
> the first 14 bytes (eth dest and src addresses 6 bytes each and frame
> tupe 2 bytes).

Ethernet calls them frames BTW.

How do you figure out how long the frame is?

JE


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